November 2021 - Linux-stable-mirror

FAILED: patch "[PATCH] PCI: aardvark: Fix support for bus mastering and PCI_COMMAND" failed to apply to 4.19-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.19-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 771153fc884f566a89af2d30033b7f3bc6e24e84 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Pali=20Roh=C3=A1r?= <pali(a)kernel.org> Date: Thu, 28 Oct 2021 20:56:56 +0200 Subject: [PATCH] PCI: aardvark: Fix support for bus mastering and PCI_COMMAND on emulated bridge MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit >From very vague, ambiguous and incomplete information from Marvell we deduced that the 32-bit Aardvark register at address 0x4 (PCIE_CORE_CMD_STATUS_REG), which is not documented for Root Complex mode in the Functional Specification (only for Endpoint mode), controls two 16-bit PCIe registers: Command Register and Status Registers of PCIe Root Port. This means that bit 2 controls bus mastering and forwarding of memory and I/O requests in the upstream direction. According to PCI specifications bits [0:2] of Command Register, this should be by default disabled on reset. So explicitly disable these bits at early setup of the Aardvark driver. Remove code which unconditionally enables all 3 bits and let kernel code (via pci_set_master() function) to handle bus mastering of Root PCIe Bridge via emulated PCI_COMMAND on emulated bridge. Link: https://lore.kernel.org/r/20211028185659.20329-5-kabel@kernel.org Fixes: 8a3ebd8de328 ("PCI: aardvark: Implement emulated root PCI bridge config space") Signed-off-by: Pali Rohár <pali(a)kernel.org> Signed-off-by: Marek Behún <kabel(a)kernel.org> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi(a)arm.com> Cc: stable(a)vger.kernel.org # b2a56469d550 ("PCI: aardvark: Add FIXME comment for PCIE_CORE_CMD_STATUS_REG access") diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c index 389ebba1dd9b..d7db03da4d1c 100644 --- a/drivers/pci/controller/pci-aardvark.c +++ b/drivers/pci/controller/pci-aardvark.c @@ -31,9 +31,6 @@ /* PCIe core registers */ #define PCIE_CORE_DEV_ID_REG 0x0 #define PCIE_CORE_CMD_STATUS_REG 0x4 -#define PCIE_CORE_CMD_IO_ACCESS_EN BIT(0) -#define PCIE_CORE_CMD_MEM_ACCESS_EN BIT(1) -#define PCIE_CORE_CMD_MEM_IO_REQ_EN BIT(2) #define PCIE_CORE_DEV_REV_REG 0x8 #define PCIE_CORE_PCIEXP_CAP 0xc0 #define PCIE_CORE_ERR_CAPCTL_REG 0x118 @@ -514,6 +511,11 @@ static void advk_pcie_setup_hw(struct advk_pcie *pcie) reg = (PCI_VENDOR_ID_MARVELL << 16) | PCI_VENDOR_ID_MARVELL; advk_writel(pcie, reg, VENDOR_ID_REG); + /* Disable Root Bridge I/O space, memory space and bus mastering */ + reg = advk_readl(pcie, PCIE_CORE_CMD_STATUS_REG); + reg &= ~(PCI_COMMAND_IO | PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER); + advk_writel(pcie, reg, PCIE_CORE_CMD_STATUS_REG); + /* Set Advanced Error Capabilities and Control PF0 register */ reg = PCIE_CORE_ERR_CAPCTL_ECRC_CHK_TX | PCIE_CORE_ERR_CAPCTL_ECRC_CHK_TX_EN | @@ -612,19 +614,6 @@ static void advk_pcie_setup_hw(struct advk_pcie *pcie) advk_pcie_disable_ob_win(pcie, i); advk_pcie_train_link(pcie); - - /* - * FIXME: The following register update is suspicious. This register is - * applicable only when the PCI controller is configured for Endpoint - * mode, not as a Root Complex. But apparently when this code is - * removed, some cards stop working. This should be investigated and - * a comment explaining this should be put here. - */ - reg = advk_readl(pcie, PCIE_CORE_CMD_STATUS_REG); - reg |= PCIE_CORE_CMD_MEM_ACCESS_EN | - PCIE_CORE_CMD_IO_ACCESS_EN | - PCIE_CORE_CMD_MEM_IO_REQ_EN; - advk_writel(pcie, reg, PCIE_CORE_CMD_STATUS_REG); } static int advk_pcie_check_pio_status(struct advk_pcie *pcie, bool allow_crs, u32 *val) @@ -753,6 +742,37 @@ static int advk_pcie_wait_pio(struct advk_pcie *pcie) return -ETIMEDOUT; } +static pci_bridge_emul_read_status_t +advk_pci_bridge_emul_base_conf_read(struct pci_bridge_emul *bridge, + int reg, u32 *value) +{ + struct advk_pcie *pcie = bridge->data; + + switch (reg) { + case PCI_COMMAND: + *value = advk_readl(pcie, PCIE_CORE_CMD_STATUS_REG); + return PCI_BRIDGE_EMUL_HANDLED; + + default: + return PCI_BRIDGE_EMUL_NOT_HANDLED; + } +} + +static void +advk_pci_bridge_emul_base_conf_write(struct pci_bridge_emul *bridge, + int reg, u32 old, u32 new, u32 mask) +{ + struct advk_pcie *pcie = bridge->data; + + switch (reg) { + case PCI_COMMAND: + advk_writel(pcie, new, PCIE_CORE_CMD_STATUS_REG); + break; + + default: + break; + } +} static pci_bridge_emul_read_status_t advk_pci_bridge_emul_pcie_conf_read(struct pci_bridge_emul *bridge, @@ -854,6 +874,8 @@ advk_pci_bridge_emul_pcie_conf_write(struct pci_bridge_emul *bridge, } static struct pci_bridge_emul_ops advk_pci_bridge_emul_ops = { + .read_base = advk_pci_bridge_emul_base_conf_read, + .write_base = advk_pci_bridge_emul_base_conf_write, .read_pcie = advk_pci_bridge_emul_pcie_conf_read, .write_pcie = advk_pci_bridge_emul_pcie_conf_write, };

3 years, 1 month

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FAILED: patch "[PATCH] PCI: aardvark: Fix checking for link up via LTSSM state" failed to apply to 4.19-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.19-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 661c399a651c11aaf83c45cbfe0b4a1fb7bc3179 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Pali=20Roh=C3=A1r?= <pali(a)kernel.org> Date: Tue, 5 Oct 2021 20:09:51 +0200 Subject: [PATCH] PCI: aardvark: Fix checking for link up via LTSSM state MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Current implementation of advk_pcie_link_up() is wrong as it marks also link disabled or hot reset states as link up. Fix it by marking link up only to those states which are defined in PCIe Base specification 3.0, Table 4-14: Link Status Mapped to the LTSSM. To simplify implementation, Define macros for every LTSSM state which aardvark hardware can return in CFG_REG register. Fix also checking for link training according to the same Table 4-14. Define a new function advk_pcie_link_training() for this purpose. Link: https://lore.kernel.org/r/20211005180952.6812-13-kabel@kernel.org Fixes: 8c39d710363c ("PCI: aardvark: Add Aardvark PCI host controller driver") Signed-off-by: Pali Rohár <pali(a)kernel.org> Signed-off-by: Marek Behún <kabel(a)kernel.org> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi(a)arm.com> Reviewed-by: Marek Behún <kabel(a)kernel.org> Cc: stable(a)vger.kernel.org Cc: Remi Pommarel <repk(a)triplefau.lt> diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c index 2c66cdbb8dd6..f831f7d197bd 100644 --- a/drivers/pci/controller/pci-aardvark.c +++ b/drivers/pci/controller/pci-aardvark.c @@ -165,8 +165,50 @@ #define CFG_REG (LMI_BASE_ADDR + 0x0) #define LTSSM_SHIFT 24 #define LTSSM_MASK 0x3f -#define LTSSM_L0 0x10 #define RC_BAR_CONFIG 0x300 + +/* LTSSM values in CFG_REG */ +enum { + LTSSM_DETECT_QUIET = 0x0, + LTSSM_DETECT_ACTIVE = 0x1, + LTSSM_POLLING_ACTIVE = 0x2, + LTSSM_POLLING_COMPLIANCE = 0x3, + LTSSM_POLLING_CONFIGURATION = 0x4, + LTSSM_CONFIG_LINKWIDTH_START = 0x5, + LTSSM_CONFIG_LINKWIDTH_ACCEPT = 0x6, + LTSSM_CONFIG_LANENUM_ACCEPT = 0x7, + LTSSM_CONFIG_LANENUM_WAIT = 0x8, + LTSSM_CONFIG_COMPLETE = 0x9, + LTSSM_CONFIG_IDLE = 0xa, + LTSSM_RECOVERY_RCVR_LOCK = 0xb, + LTSSM_RECOVERY_SPEED = 0xc, + LTSSM_RECOVERY_RCVR_CFG = 0xd, + LTSSM_RECOVERY_IDLE = 0xe, + LTSSM_L0 = 0x10, + LTSSM_RX_L0S_ENTRY = 0x11, + LTSSM_RX_L0S_IDLE = 0x12, + LTSSM_RX_L0S_FTS = 0x13, + LTSSM_TX_L0S_ENTRY = 0x14, + LTSSM_TX_L0S_IDLE = 0x15, + LTSSM_TX_L0S_FTS = 0x16, + LTSSM_L1_ENTRY = 0x17, + LTSSM_L1_IDLE = 0x18, + LTSSM_L2_IDLE = 0x19, + LTSSM_L2_TRANSMIT_WAKE = 0x1a, + LTSSM_DISABLED = 0x20, + LTSSM_LOOPBACK_ENTRY_MASTER = 0x21, + LTSSM_LOOPBACK_ACTIVE_MASTER = 0x22, + LTSSM_LOOPBACK_EXIT_MASTER = 0x23, + LTSSM_LOOPBACK_ENTRY_SLAVE = 0x24, + LTSSM_LOOPBACK_ACTIVE_SLAVE = 0x25, + LTSSM_LOOPBACK_EXIT_SLAVE = 0x26, + LTSSM_HOT_RESET = 0x27, + LTSSM_RECOVERY_EQUALIZATION_PHASE0 = 0x28, + LTSSM_RECOVERY_EQUALIZATION_PHASE1 = 0x29, + LTSSM_RECOVERY_EQUALIZATION_PHASE2 = 0x2a, + LTSSM_RECOVERY_EQUALIZATION_PHASE3 = 0x2b, +}; + #define VENDOR_ID_REG (LMI_BASE_ADDR + 0x44) /* PCIe core controller registers */ @@ -258,13 +300,35 @@ static inline u32 advk_readl(struct advk_pcie *pcie, u64 reg) return readl(pcie->base + reg); } -static int advk_pcie_link_up(struct advk_pcie *pcie) +static u8 advk_pcie_ltssm_state(struct advk_pcie *pcie) { - u32 val, ltssm_state; + u32 val; + u8 ltssm_state; val = advk_readl(pcie, CFG_REG); ltssm_state = (val >> LTSSM_SHIFT) & LTSSM_MASK; - return ltssm_state >= LTSSM_L0; + return ltssm_state; +} + +static inline bool advk_pcie_link_up(struct advk_pcie *pcie) +{ + /* check if LTSSM is in normal operation - some L* state */ + u8 ltssm_state = advk_pcie_ltssm_state(pcie); + return ltssm_state >= LTSSM_L0 && ltssm_state < LTSSM_DISABLED; +} + +static inline bool advk_pcie_link_training(struct advk_pcie *pcie) +{ + /* + * According to PCIe Base specification 3.0, Table 4-14: Link + * Status Mapped to the LTSSM is Link Training mapped to LTSSM + * Configuration and Recovery states. + */ + u8 ltssm_state = advk_pcie_ltssm_state(pcie); + return ((ltssm_state >= LTSSM_CONFIG_LINKWIDTH_START && + ltssm_state < LTSSM_L0) || + (ltssm_state >= LTSSM_RECOVERY_EQUALIZATION_PHASE0 && + ltssm_state <= LTSSM_RECOVERY_EQUALIZATION_PHASE3)); } static int advk_pcie_wait_for_link(struct advk_pcie *pcie) @@ -287,7 +351,7 @@ static void advk_pcie_wait_for_retrain(struct advk_pcie *pcie) size_t retries; for (retries = 0; retries < RETRAIN_WAIT_MAX_RETRIES; ++retries) { - if (!advk_pcie_link_up(pcie)) + if (advk_pcie_link_training(pcie)) break; udelay(RETRAIN_WAIT_USLEEP_US); } @@ -706,7 +770,7 @@ advk_pci_bridge_emul_pcie_conf_read(struct pci_bridge_emul *bridge, /* u32 contains both PCI_EXP_LNKCTL and PCI_EXP_LNKSTA */ u32 val = advk_readl(pcie, PCIE_CORE_PCIEXP_CAP + reg) & ~(PCI_EXP_LNKSTA_LT << 16); - if (!advk_pcie_link_up(pcie)) + if (advk_pcie_link_training(pcie)) val |= (PCI_EXP_LNKSTA_LT << 16); *value = val; return PCI_BRIDGE_EMUL_HANDLED;

3 years, 1 month

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FAILED: patch "[PATCH] PCI: aardvark: Fix checking for link up via LTSSM state" failed to apply to 4.14-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.14-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 661c399a651c11aaf83c45cbfe0b4a1fb7bc3179 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Pali=20Roh=C3=A1r?= <pali(a)kernel.org> Date: Tue, 5 Oct 2021 20:09:51 +0200 Subject: [PATCH] PCI: aardvark: Fix checking for link up via LTSSM state MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Current implementation of advk_pcie_link_up() is wrong as it marks also link disabled or hot reset states as link up. Fix it by marking link up only to those states which are defined in PCIe Base specification 3.0, Table 4-14: Link Status Mapped to the LTSSM. To simplify implementation, Define macros for every LTSSM state which aardvark hardware can return in CFG_REG register. Fix also checking for link training according to the same Table 4-14. Define a new function advk_pcie_link_training() for this purpose. Link: https://lore.kernel.org/r/20211005180952.6812-13-kabel@kernel.org Fixes: 8c39d710363c ("PCI: aardvark: Add Aardvark PCI host controller driver") Signed-off-by: Pali Rohár <pali(a)kernel.org> Signed-off-by: Marek Behún <kabel(a)kernel.org> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi(a)arm.com> Reviewed-by: Marek Behún <kabel(a)kernel.org> Cc: stable(a)vger.kernel.org Cc: Remi Pommarel <repk(a)triplefau.lt> diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c index 2c66cdbb8dd6..f831f7d197bd 100644 --- a/drivers/pci/controller/pci-aardvark.c +++ b/drivers/pci/controller/pci-aardvark.c @@ -165,8 +165,50 @@ #define CFG_REG (LMI_BASE_ADDR + 0x0) #define LTSSM_SHIFT 24 #define LTSSM_MASK 0x3f -#define LTSSM_L0 0x10 #define RC_BAR_CONFIG 0x300 + +/* LTSSM values in CFG_REG */ +enum { + LTSSM_DETECT_QUIET = 0x0, + LTSSM_DETECT_ACTIVE = 0x1, + LTSSM_POLLING_ACTIVE = 0x2, + LTSSM_POLLING_COMPLIANCE = 0x3, + LTSSM_POLLING_CONFIGURATION = 0x4, + LTSSM_CONFIG_LINKWIDTH_START = 0x5, + LTSSM_CONFIG_LINKWIDTH_ACCEPT = 0x6, + LTSSM_CONFIG_LANENUM_ACCEPT = 0x7, + LTSSM_CONFIG_LANENUM_WAIT = 0x8, + LTSSM_CONFIG_COMPLETE = 0x9, + LTSSM_CONFIG_IDLE = 0xa, + LTSSM_RECOVERY_RCVR_LOCK = 0xb, + LTSSM_RECOVERY_SPEED = 0xc, + LTSSM_RECOVERY_RCVR_CFG = 0xd, + LTSSM_RECOVERY_IDLE = 0xe, + LTSSM_L0 = 0x10, + LTSSM_RX_L0S_ENTRY = 0x11, + LTSSM_RX_L0S_IDLE = 0x12, + LTSSM_RX_L0S_FTS = 0x13, + LTSSM_TX_L0S_ENTRY = 0x14, + LTSSM_TX_L0S_IDLE = 0x15, + LTSSM_TX_L0S_FTS = 0x16, + LTSSM_L1_ENTRY = 0x17, + LTSSM_L1_IDLE = 0x18, + LTSSM_L2_IDLE = 0x19, + LTSSM_L2_TRANSMIT_WAKE = 0x1a, + LTSSM_DISABLED = 0x20, + LTSSM_LOOPBACK_ENTRY_MASTER = 0x21, + LTSSM_LOOPBACK_ACTIVE_MASTER = 0x22, + LTSSM_LOOPBACK_EXIT_MASTER = 0x23, + LTSSM_LOOPBACK_ENTRY_SLAVE = 0x24, + LTSSM_LOOPBACK_ACTIVE_SLAVE = 0x25, + LTSSM_LOOPBACK_EXIT_SLAVE = 0x26, + LTSSM_HOT_RESET = 0x27, + LTSSM_RECOVERY_EQUALIZATION_PHASE0 = 0x28, + LTSSM_RECOVERY_EQUALIZATION_PHASE1 = 0x29, + LTSSM_RECOVERY_EQUALIZATION_PHASE2 = 0x2a, + LTSSM_RECOVERY_EQUALIZATION_PHASE3 = 0x2b, +}; + #define VENDOR_ID_REG (LMI_BASE_ADDR + 0x44) /* PCIe core controller registers */ @@ -258,13 +300,35 @@ static inline u32 advk_readl(struct advk_pcie *pcie, u64 reg) return readl(pcie->base + reg); } -static int advk_pcie_link_up(struct advk_pcie *pcie) +static u8 advk_pcie_ltssm_state(struct advk_pcie *pcie) { - u32 val, ltssm_state; + u32 val; + u8 ltssm_state; val = advk_readl(pcie, CFG_REG); ltssm_state = (val >> LTSSM_SHIFT) & LTSSM_MASK; - return ltssm_state >= LTSSM_L0; + return ltssm_state; +} + +static inline bool advk_pcie_link_up(struct advk_pcie *pcie) +{ + /* check if LTSSM is in normal operation - some L* state */ + u8 ltssm_state = advk_pcie_ltssm_state(pcie); + return ltssm_state >= LTSSM_L0 && ltssm_state < LTSSM_DISABLED; +} + +static inline bool advk_pcie_link_training(struct advk_pcie *pcie) +{ + /* + * According to PCIe Base specification 3.0, Table 4-14: Link + * Status Mapped to the LTSSM is Link Training mapped to LTSSM + * Configuration and Recovery states. + */ + u8 ltssm_state = advk_pcie_ltssm_state(pcie); + return ((ltssm_state >= LTSSM_CONFIG_LINKWIDTH_START && + ltssm_state < LTSSM_L0) || + (ltssm_state >= LTSSM_RECOVERY_EQUALIZATION_PHASE0 && + ltssm_state <= LTSSM_RECOVERY_EQUALIZATION_PHASE3)); } static int advk_pcie_wait_for_link(struct advk_pcie *pcie) @@ -287,7 +351,7 @@ static void advk_pcie_wait_for_retrain(struct advk_pcie *pcie) size_t retries; for (retries = 0; retries < RETRAIN_WAIT_MAX_RETRIES; ++retries) { - if (!advk_pcie_link_up(pcie)) + if (advk_pcie_link_training(pcie)) break; udelay(RETRAIN_WAIT_USLEEP_US); } @@ -706,7 +770,7 @@ advk_pci_bridge_emul_pcie_conf_read(struct pci_bridge_emul *bridge, /* u32 contains both PCI_EXP_LNKCTL and PCI_EXP_LNKSTA */ u32 val = advk_readl(pcie, PCIE_CORE_PCIEXP_CAP + reg) & ~(PCI_EXP_LNKSTA_LT << 16); - if (!advk_pcie_link_up(pcie)) + if (advk_pcie_link_training(pcie)) val |= (PCI_EXP_LNKSTA_LT << 16); *value = val; return PCI_BRIDGE_EMUL_HANDLED;

3 years, 1 month

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FAILED: patch "[PATCH] PCI: aardvark: Fix PCIe Max Payload Size setting" failed to apply to 4.14-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.14-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From a4e17d65dafdd3513042d8f00404c9b6068a825c Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Pali=20Roh=C3=A1r?= <pali(a)kernel.org> Date: Tue, 5 Oct 2021 20:09:41 +0200 Subject: [PATCH] PCI: aardvark: Fix PCIe Max Payload Size setting MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Change PCIe Max Payload Size setting in PCIe Device Control register to 512 bytes to align with PCIe Link Initialization sequence as defined in Marvell Armada 3700 Functional Specification. According to the specification, maximal Max Payload Size supported by this device is 512 bytes. Without this kernel prints suspicious line: pci 0000:01:00.0: Upstream bridge's Max Payload Size set to 256 (was 16384, max 512) With this change it changes to: pci 0000:01:00.0: Upstream bridge's Max Payload Size set to 256 (was 512, max 512) Link: https://lore.kernel.org/r/20211005180952.6812-3-kabel@kernel.org Fixes: 8c39d710363c ("PCI: aardvark: Add Aardvark PCI host controller driver") Signed-off-by: Pali Rohár <pali(a)kernel.org> Signed-off-by: Marek Behún <kabel(a)kernel.org> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi(a)arm.com> Reviewed-by: Marek Behún <kabel(a)kernel.org> Cc: stable(a)vger.kernel.org diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c index 596ebcfcc82d..884510630bae 100644 --- a/drivers/pci/controller/pci-aardvark.c +++ b/drivers/pci/controller/pci-aardvark.c @@ -488,8 +488,9 @@ static void advk_pcie_setup_hw(struct advk_pcie *pcie) reg = advk_readl(pcie, PCIE_CORE_PCIEXP_CAP + PCI_EXP_DEVCTL); reg &= ~PCI_EXP_DEVCTL_RELAX_EN; reg &= ~PCI_EXP_DEVCTL_NOSNOOP_EN; + reg &= ~PCI_EXP_DEVCTL_PAYLOAD; reg &= ~PCI_EXP_DEVCTL_READRQ; - reg |= PCI_EXP_DEVCTL_PAYLOAD; /* Set max payload size */ + reg |= PCI_EXP_DEVCTL_PAYLOAD_512B; reg |= PCI_EXP_DEVCTL_READRQ_512B; advk_writel(pcie, reg, PCIE_CORE_PCIEXP_CAP + PCI_EXP_DEVCTL);

3 years, 1 month

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FAILED: patch "[PATCH] PCI: aardvark: Fix PCIe Max Payload Size setting" failed to apply to 4.19-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.19-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From a4e17d65dafdd3513042d8f00404c9b6068a825c Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Pali=20Roh=C3=A1r?= <pali(a)kernel.org> Date: Tue, 5 Oct 2021 20:09:41 +0200 Subject: [PATCH] PCI: aardvark: Fix PCIe Max Payload Size setting MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Change PCIe Max Payload Size setting in PCIe Device Control register to 512 bytes to align with PCIe Link Initialization sequence as defined in Marvell Armada 3700 Functional Specification. According to the specification, maximal Max Payload Size supported by this device is 512 bytes. Without this kernel prints suspicious line: pci 0000:01:00.0: Upstream bridge's Max Payload Size set to 256 (was 16384, max 512) With this change it changes to: pci 0000:01:00.0: Upstream bridge's Max Payload Size set to 256 (was 512, max 512) Link: https://lore.kernel.org/r/20211005180952.6812-3-kabel@kernel.org Fixes: 8c39d710363c ("PCI: aardvark: Add Aardvark PCI host controller driver") Signed-off-by: Pali Rohár <pali(a)kernel.org> Signed-off-by: Marek Behún <kabel(a)kernel.org> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi(a)arm.com> Reviewed-by: Marek Behún <kabel(a)kernel.org> Cc: stable(a)vger.kernel.org diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c index 596ebcfcc82d..884510630bae 100644 --- a/drivers/pci/controller/pci-aardvark.c +++ b/drivers/pci/controller/pci-aardvark.c @@ -488,8 +488,9 @@ static void advk_pcie_setup_hw(struct advk_pcie *pcie) reg = advk_readl(pcie, PCIE_CORE_PCIEXP_CAP + PCI_EXP_DEVCTL); reg &= ~PCI_EXP_DEVCTL_RELAX_EN; reg &= ~PCI_EXP_DEVCTL_NOSNOOP_EN; + reg &= ~PCI_EXP_DEVCTL_PAYLOAD; reg &= ~PCI_EXP_DEVCTL_READRQ; - reg |= PCI_EXP_DEVCTL_PAYLOAD; /* Set max payload size */ + reg |= PCI_EXP_DEVCTL_PAYLOAD_512B; reg |= PCI_EXP_DEVCTL_READRQ_512B; advk_writel(pcie, reg, PCIE_CORE_PCIEXP_CAP + PCI_EXP_DEVCTL);

3 years, 1 month

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FAILED: patch "[PATCH] PCI: aardvark: Fix PCIe Max Payload Size setting" failed to apply to 5.4-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From a4e17d65dafdd3513042d8f00404c9b6068a825c Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Pali=20Roh=C3=A1r?= <pali(a)kernel.org> Date: Tue, 5 Oct 2021 20:09:41 +0200 Subject: [PATCH] PCI: aardvark: Fix PCIe Max Payload Size setting MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Change PCIe Max Payload Size setting in PCIe Device Control register to 512 bytes to align with PCIe Link Initialization sequence as defined in Marvell Armada 3700 Functional Specification. According to the specification, maximal Max Payload Size supported by this device is 512 bytes. Without this kernel prints suspicious line: pci 0000:01:00.0: Upstream bridge's Max Payload Size set to 256 (was 16384, max 512) With this change it changes to: pci 0000:01:00.0: Upstream bridge's Max Payload Size set to 256 (was 512, max 512) Link: https://lore.kernel.org/r/20211005180952.6812-3-kabel@kernel.org Fixes: 8c39d710363c ("PCI: aardvark: Add Aardvark PCI host controller driver") Signed-off-by: Pali Rohár <pali(a)kernel.org> Signed-off-by: Marek Behún <kabel(a)kernel.org> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi(a)arm.com> Reviewed-by: Marek Behún <kabel(a)kernel.org> Cc: stable(a)vger.kernel.org diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c index 596ebcfcc82d..884510630bae 100644 --- a/drivers/pci/controller/pci-aardvark.c +++ b/drivers/pci/controller/pci-aardvark.c @@ -488,8 +488,9 @@ static void advk_pcie_setup_hw(struct advk_pcie *pcie) reg = advk_readl(pcie, PCIE_CORE_PCIEXP_CAP + PCI_EXP_DEVCTL); reg &= ~PCI_EXP_DEVCTL_RELAX_EN; reg &= ~PCI_EXP_DEVCTL_NOSNOOP_EN; + reg &= ~PCI_EXP_DEVCTL_PAYLOAD; reg &= ~PCI_EXP_DEVCTL_READRQ; - reg |= PCI_EXP_DEVCTL_PAYLOAD; /* Set max payload size */ + reg |= PCI_EXP_DEVCTL_PAYLOAD_512B; reg |= PCI_EXP_DEVCTL_READRQ_512B; advk_writel(pcie, reg, PCIE_CORE_PCIEXP_CAP + PCI_EXP_DEVCTL);

3 years, 1 month

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Re: Details and Specifications

by Root User

11/14/2021 01:47:31 pm Good day, I sent an earlier email to stable(a)vger.kernel.org with all the details, did you see it or do I resend it again? Regards, Juaquin Dabeer

3 years, 1 month

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FAILED: patch "[PATCH] PCI: pciehp: Ignore Link Down/Up caused by error-induced Hot" failed to apply to 4.19-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.19-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From ea401499e943c307e6d44af6c2b4e068643e7884 Mon Sep 17 00:00:00 2001 From: Lukas Wunner <lukas(a)wunner.de> Date: Sat, 31 Jul 2021 14:39:01 +0200 Subject: [PATCH] PCI: pciehp: Ignore Link Down/Up caused by error-induced Hot Reset Stuart Hayes reports that an error handled by DPC at a Root Port results in pciehp gratuitously bringing down a subordinate hotplug port: RP -- UP -- DP -- UP -- DP (hotplug) -- EP pciehp brings the slot down because the Link to the Endpoint goes down. That is caused by a Hot Reset being propagated as a result of DPC. Per PCIe Base Spec 5.0, section 6.6.1 "Conventional Reset": For a Switch, the following must cause a hot reset to be sent on all Downstream Ports: [...] * The Data Link Layer of the Upstream Port reporting DL_Down status. In Switches that support Link speeds greater than 5.0 GT/s, the Upstream Port must direct the LTSSM of each Downstream Port to the Hot Reset state, but not hold the LTSSMs in that state. This permits each Downstream Port to begin Link training immediately after its hot reset completes. This behavior is recommended for all Switches. * Receiving a hot reset on the Upstream Port. Once DPC recovers, pcie_do_recovery() walks down the hierarchy and invokes pcie_portdrv_slot_reset() to restore each port's config space. At that point, a hotplug interrupt is signaled per PCIe Base Spec r5.0, section 6.7.3.4 "Software Notification of Hot-Plug Events": If the Port is enabled for edge-triggered interrupt signaling using MSI or MSI-X, an interrupt message must be sent every time the logical AND of the following conditions transitions from FALSE to TRUE: [...] * The Hot-Plug Interrupt Enable bit in the Slot Control register is set to 1b. * At least one hot-plug event status bit in the Slot Status register and its associated enable bit in the Slot Control register are both set to 1b. Prevent pciehp from gratuitously bringing down the slot by clearing the error-induced Data Link Layer State Changed event before restoring config space. Afterwards, check whether the link has unexpectedly failed to retrain and synthesize a DLLSC event if so. Allow each pcie_port_service_driver (one of them being pciehp) to define a slot_reset callback and re-use the existing pm_iter() function to iterate over the callbacks. Thereby, the Endpoint driver remains bound throughout error recovery and may restore the device to working state. Surprise removal during error recovery is detected through a Presence Detect Changed event. The hotplug port is expected to not signal that event as a result of a Hot Reset. The issue isn't DPC-specific, it also occurs when an error is handled by AER through aer_root_reset(). So while the issue was noticed only now, it's been around since 2006 when AER support was first introduced. [bhelgaas: drop PCI_ERROR_RECOVERY Kconfig, split pm_iter() rename to preparatory patch] Link: https://lore.kernel.org/linux-pci/08c046b0-c9f2-3489-eeef-7e7aca435bb9@gmai… Fixes: 6c2b374d7485 ("PCI-Express AER implemetation: AER core and aerdriver") Link: https://lore.kernel.org/r/251f4edcc04c14f873ff1c967bc686169cd07d2d.16276381… Reported-by: Stuart Hayes <stuart.w.hayes(a)gmail.com> Tested-by: Stuart Hayes <stuart.w.hayes(a)gmail.com> Signed-off-by: Lukas Wunner <lukas(a)wunner.de> Signed-off-by: Bjorn Helgaas <bhelgaas(a)google.com> Cc: stable(a)vger.kernel.org # v2.6.19+: ba952824e6c1: PCI/portdrv: Report reset for frozen channel Cc: Keith Busch <kbusch(a)kernel.org> diff --git a/drivers/pci/hotplug/pciehp.h b/drivers/pci/hotplug/pciehp.h index 69fd401691be..918dccbc74b6 100644 --- a/drivers/pci/hotplug/pciehp.h +++ b/drivers/pci/hotplug/pciehp.h @@ -189,6 +189,8 @@ int pciehp_get_attention_status(struct hotplug_slot *hotplug_slot, u8 *status); int pciehp_set_raw_indicator_status(struct hotplug_slot *h_slot, u8 status); int pciehp_get_raw_indicator_status(struct hotplug_slot *h_slot, u8 *status); +int pciehp_slot_reset(struct pcie_device *dev); + static inline const char *slot_name(struct controller *ctrl) { return hotplug_slot_name(&ctrl->hotplug_slot); diff --git a/drivers/pci/hotplug/pciehp_core.c b/drivers/pci/hotplug/pciehp_core.c index ad3393930ecb..f34114d45259 100644 --- a/drivers/pci/hotplug/pciehp_core.c +++ b/drivers/pci/hotplug/pciehp_core.c @@ -351,6 +351,8 @@ static struct pcie_port_service_driver hpdriver_portdrv = { .runtime_suspend = pciehp_runtime_suspend, .runtime_resume = pciehp_runtime_resume, #endif /* PM */ + + .slot_reset = pciehp_slot_reset, }; int __init pcie_hp_init(void) diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c index 3024d7e85e6a..83a0fa119cae 100644 --- a/drivers/pci/hotplug/pciehp_hpc.c +++ b/drivers/pci/hotplug/pciehp_hpc.c @@ -862,6 +862,32 @@ void pcie_disable_interrupt(struct controller *ctrl) pcie_write_cmd(ctrl, 0, mask); } +/** + * pciehp_slot_reset() - ignore link event caused by error-induced hot reset + * @dev: PCI Express port service device + * + * Called from pcie_portdrv_slot_reset() after AER or DPC initiated a reset + * further up in the hierarchy to recover from an error. The reset was + * propagated down to this hotplug port. Ignore the resulting link flap. + * If the link failed to retrain successfully, synthesize the ignored event. + * Surprise removal during reset is detected through Presence Detect Changed. + */ +int pciehp_slot_reset(struct pcie_device *dev) +{ + struct controller *ctrl = get_service_data(dev); + + if (ctrl->state != ON_STATE) + return 0; + + pcie_capability_write_word(dev->port, PCI_EXP_SLTSTA, + PCI_EXP_SLTSTA_DLLSC); + + if (!pciehp_check_link_active(ctrl)) + pciehp_request(ctrl, PCI_EXP_SLTSTA_DLLSC); + + return 0; +} + /* * pciehp has a 1:1 bus:slot relationship so we ultimately want a secondary * bus reset of the bridge, but at the same time we want to ensure that it is diff --git a/drivers/pci/pcie/portdrv.h b/drivers/pci/pcie/portdrv.h index 6126ee4676a7..41fe1ffd5907 100644 --- a/drivers/pci/pcie/portdrv.h +++ b/drivers/pci/pcie/portdrv.h @@ -85,6 +85,8 @@ struct pcie_port_service_driver { int (*runtime_suspend)(struct pcie_device *dev); int (*runtime_resume)(struct pcie_device *dev); + int (*slot_reset)(struct pcie_device *dev); + /* Device driver may resume normal operations */ void (*error_resume)(struct pci_dev *dev); diff --git a/drivers/pci/pcie/portdrv_pci.c b/drivers/pci/pcie/portdrv_pci.c index c7ff1eea225a..1af74c3d9d5d 100644 --- a/drivers/pci/pcie/portdrv_pci.c +++ b/drivers/pci/pcie/portdrv_pci.c @@ -160,6 +160,9 @@ static pci_ers_result_t pcie_portdrv_error_detected(struct pci_dev *dev, static pci_ers_result_t pcie_portdrv_slot_reset(struct pci_dev *dev) { + size_t off = offsetof(struct pcie_port_service_driver, slot_reset); + device_for_each_child(&dev->dev, &off, pcie_port_device_iter); + pci_restore_state(dev); pci_save_state(dev); return PCI_ERS_RESULT_RECOVERED;

3 years, 1 month

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FAILED: patch "[PATCH] PCI: pciehp: Ignore Link Down/Up caused by error-induced Hot" failed to apply to 4.14-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.14-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From ea401499e943c307e6d44af6c2b4e068643e7884 Mon Sep 17 00:00:00 2001 From: Lukas Wunner <lukas(a)wunner.de> Date: Sat, 31 Jul 2021 14:39:01 +0200 Subject: [PATCH] PCI: pciehp: Ignore Link Down/Up caused by error-induced Hot Reset Stuart Hayes reports that an error handled by DPC at a Root Port results in pciehp gratuitously bringing down a subordinate hotplug port: RP -- UP -- DP -- UP -- DP (hotplug) -- EP pciehp brings the slot down because the Link to the Endpoint goes down. That is caused by a Hot Reset being propagated as a result of DPC. Per PCIe Base Spec 5.0, section 6.6.1 "Conventional Reset": For a Switch, the following must cause a hot reset to be sent on all Downstream Ports: [...] * The Data Link Layer of the Upstream Port reporting DL_Down status. In Switches that support Link speeds greater than 5.0 GT/s, the Upstream Port must direct the LTSSM of each Downstream Port to the Hot Reset state, but not hold the LTSSMs in that state. This permits each Downstream Port to begin Link training immediately after its hot reset completes. This behavior is recommended for all Switches. * Receiving a hot reset on the Upstream Port. Once DPC recovers, pcie_do_recovery() walks down the hierarchy and invokes pcie_portdrv_slot_reset() to restore each port's config space. At that point, a hotplug interrupt is signaled per PCIe Base Spec r5.0, section 6.7.3.4 "Software Notification of Hot-Plug Events": If the Port is enabled for edge-triggered interrupt signaling using MSI or MSI-X, an interrupt message must be sent every time the logical AND of the following conditions transitions from FALSE to TRUE: [...] * The Hot-Plug Interrupt Enable bit in the Slot Control register is set to 1b. * At least one hot-plug event status bit in the Slot Status register and its associated enable bit in the Slot Control register are both set to 1b. Prevent pciehp from gratuitously bringing down the slot by clearing the error-induced Data Link Layer State Changed event before restoring config space. Afterwards, check whether the link has unexpectedly failed to retrain and synthesize a DLLSC event if so. Allow each pcie_port_service_driver (one of them being pciehp) to define a slot_reset callback and re-use the existing pm_iter() function to iterate over the callbacks. Thereby, the Endpoint driver remains bound throughout error recovery and may restore the device to working state. Surprise removal during error recovery is detected through a Presence Detect Changed event. The hotplug port is expected to not signal that event as a result of a Hot Reset. The issue isn't DPC-specific, it also occurs when an error is handled by AER through aer_root_reset(). So while the issue was noticed only now, it's been around since 2006 when AER support was first introduced. [bhelgaas: drop PCI_ERROR_RECOVERY Kconfig, split pm_iter() rename to preparatory patch] Link: https://lore.kernel.org/linux-pci/08c046b0-c9f2-3489-eeef-7e7aca435bb9@gmai… Fixes: 6c2b374d7485 ("PCI-Express AER implemetation: AER core and aerdriver") Link: https://lore.kernel.org/r/251f4edcc04c14f873ff1c967bc686169cd07d2d.16276381… Reported-by: Stuart Hayes <stuart.w.hayes(a)gmail.com> Tested-by: Stuart Hayes <stuart.w.hayes(a)gmail.com> Signed-off-by: Lukas Wunner <lukas(a)wunner.de> Signed-off-by: Bjorn Helgaas <bhelgaas(a)google.com> Cc: stable(a)vger.kernel.org # v2.6.19+: ba952824e6c1: PCI/portdrv: Report reset for frozen channel Cc: Keith Busch <kbusch(a)kernel.org> diff --git a/drivers/pci/hotplug/pciehp.h b/drivers/pci/hotplug/pciehp.h index 69fd401691be..918dccbc74b6 100644 --- a/drivers/pci/hotplug/pciehp.h +++ b/drivers/pci/hotplug/pciehp.h @@ -189,6 +189,8 @@ int pciehp_get_attention_status(struct hotplug_slot *hotplug_slot, u8 *status); int pciehp_set_raw_indicator_status(struct hotplug_slot *h_slot, u8 status); int pciehp_get_raw_indicator_status(struct hotplug_slot *h_slot, u8 *status); +int pciehp_slot_reset(struct pcie_device *dev); + static inline const char *slot_name(struct controller *ctrl) { return hotplug_slot_name(&ctrl->hotplug_slot); diff --git a/drivers/pci/hotplug/pciehp_core.c b/drivers/pci/hotplug/pciehp_core.c index ad3393930ecb..f34114d45259 100644 --- a/drivers/pci/hotplug/pciehp_core.c +++ b/drivers/pci/hotplug/pciehp_core.c @@ -351,6 +351,8 @@ static struct pcie_port_service_driver hpdriver_portdrv = { .runtime_suspend = pciehp_runtime_suspend, .runtime_resume = pciehp_runtime_resume, #endif /* PM */ + + .slot_reset = pciehp_slot_reset, }; int __init pcie_hp_init(void) diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c index 3024d7e85e6a..83a0fa119cae 100644 --- a/drivers/pci/hotplug/pciehp_hpc.c +++ b/drivers/pci/hotplug/pciehp_hpc.c @@ -862,6 +862,32 @@ void pcie_disable_interrupt(struct controller *ctrl) pcie_write_cmd(ctrl, 0, mask); } +/** + * pciehp_slot_reset() - ignore link event caused by error-induced hot reset + * @dev: PCI Express port service device + * + * Called from pcie_portdrv_slot_reset() after AER or DPC initiated a reset + * further up in the hierarchy to recover from an error. The reset was + * propagated down to this hotplug port. Ignore the resulting link flap. + * If the link failed to retrain successfully, synthesize the ignored event. + * Surprise removal during reset is detected through Presence Detect Changed. + */ +int pciehp_slot_reset(struct pcie_device *dev) +{ + struct controller *ctrl = get_service_data(dev); + + if (ctrl->state != ON_STATE) + return 0; + + pcie_capability_write_word(dev->port, PCI_EXP_SLTSTA, + PCI_EXP_SLTSTA_DLLSC); + + if (!pciehp_check_link_active(ctrl)) + pciehp_request(ctrl, PCI_EXP_SLTSTA_DLLSC); + + return 0; +} + /* * pciehp has a 1:1 bus:slot relationship so we ultimately want a secondary * bus reset of the bridge, but at the same time we want to ensure that it is diff --git a/drivers/pci/pcie/portdrv.h b/drivers/pci/pcie/portdrv.h index 6126ee4676a7..41fe1ffd5907 100644 --- a/drivers/pci/pcie/portdrv.h +++ b/drivers/pci/pcie/portdrv.h @@ -85,6 +85,8 @@ struct pcie_port_service_driver { int (*runtime_suspend)(struct pcie_device *dev); int (*runtime_resume)(struct pcie_device *dev); + int (*slot_reset)(struct pcie_device *dev); + /* Device driver may resume normal operations */ void (*error_resume)(struct pci_dev *dev); diff --git a/drivers/pci/pcie/portdrv_pci.c b/drivers/pci/pcie/portdrv_pci.c index c7ff1eea225a..1af74c3d9d5d 100644 --- a/drivers/pci/pcie/portdrv_pci.c +++ b/drivers/pci/pcie/portdrv_pci.c @@ -160,6 +160,9 @@ static pci_ers_result_t pcie_portdrv_error_detected(struct pci_dev *dev, static pci_ers_result_t pcie_portdrv_slot_reset(struct pci_dev *dev) { + size_t off = offsetof(struct pcie_port_service_driver, slot_reset); + device_for_each_child(&dev->dev, &off, pcie_port_device_iter); + pci_restore_state(dev); pci_save_state(dev); return PCI_ERS_RESULT_RECOVERED;

3 years, 1 month

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FAILED: patch "[PATCH] PCI: pciehp: Ignore Link Down/Up caused by error-induced Hot" failed to apply to 4.9-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.9-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From ea401499e943c307e6d44af6c2b4e068643e7884 Mon Sep 17 00:00:00 2001 From: Lukas Wunner <lukas(a)wunner.de> Date: Sat, 31 Jul 2021 14:39:01 +0200 Subject: [PATCH] PCI: pciehp: Ignore Link Down/Up caused by error-induced Hot Reset Stuart Hayes reports that an error handled by DPC at a Root Port results in pciehp gratuitously bringing down a subordinate hotplug port: RP -- UP -- DP -- UP -- DP (hotplug) -- EP pciehp brings the slot down because the Link to the Endpoint goes down. That is caused by a Hot Reset being propagated as a result of DPC. Per PCIe Base Spec 5.0, section 6.6.1 "Conventional Reset": For a Switch, the following must cause a hot reset to be sent on all Downstream Ports: [...] * The Data Link Layer of the Upstream Port reporting DL_Down status. In Switches that support Link speeds greater than 5.0 GT/s, the Upstream Port must direct the LTSSM of each Downstream Port to the Hot Reset state, but not hold the LTSSMs in that state. This permits each Downstream Port to begin Link training immediately after its hot reset completes. This behavior is recommended for all Switches. * Receiving a hot reset on the Upstream Port. Once DPC recovers, pcie_do_recovery() walks down the hierarchy and invokes pcie_portdrv_slot_reset() to restore each port's config space. At that point, a hotplug interrupt is signaled per PCIe Base Spec r5.0, section 6.7.3.4 "Software Notification of Hot-Plug Events": If the Port is enabled for edge-triggered interrupt signaling using MSI or MSI-X, an interrupt message must be sent every time the logical AND of the following conditions transitions from FALSE to TRUE: [...] * The Hot-Plug Interrupt Enable bit in the Slot Control register is set to 1b. * At least one hot-plug event status bit in the Slot Status register and its associated enable bit in the Slot Control register are both set to 1b. Prevent pciehp from gratuitously bringing down the slot by clearing the error-induced Data Link Layer State Changed event before restoring config space. Afterwards, check whether the link has unexpectedly failed to retrain and synthesize a DLLSC event if so. Allow each pcie_port_service_driver (one of them being pciehp) to define a slot_reset callback and re-use the existing pm_iter() function to iterate over the callbacks. Thereby, the Endpoint driver remains bound throughout error recovery and may restore the device to working state. Surprise removal during error recovery is detected through a Presence Detect Changed event. The hotplug port is expected to not signal that event as a result of a Hot Reset. The issue isn't DPC-specific, it also occurs when an error is handled by AER through aer_root_reset(). So while the issue was noticed only now, it's been around since 2006 when AER support was first introduced. [bhelgaas: drop PCI_ERROR_RECOVERY Kconfig, split pm_iter() rename to preparatory patch] Link: https://lore.kernel.org/linux-pci/08c046b0-c9f2-3489-eeef-7e7aca435bb9@gmai… Fixes: 6c2b374d7485 ("PCI-Express AER implemetation: AER core and aerdriver") Link: https://lore.kernel.org/r/251f4edcc04c14f873ff1c967bc686169cd07d2d.16276381… Reported-by: Stuart Hayes <stuart.w.hayes(a)gmail.com> Tested-by: Stuart Hayes <stuart.w.hayes(a)gmail.com> Signed-off-by: Lukas Wunner <lukas(a)wunner.de> Signed-off-by: Bjorn Helgaas <bhelgaas(a)google.com> Cc: stable(a)vger.kernel.org # v2.6.19+: ba952824e6c1: PCI/portdrv: Report reset for frozen channel Cc: Keith Busch <kbusch(a)kernel.org> diff --git a/drivers/pci/hotplug/pciehp.h b/drivers/pci/hotplug/pciehp.h index 69fd401691be..918dccbc74b6 100644 --- a/drivers/pci/hotplug/pciehp.h +++ b/drivers/pci/hotplug/pciehp.h @@ -189,6 +189,8 @@ int pciehp_get_attention_status(struct hotplug_slot *hotplug_slot, u8 *status); int pciehp_set_raw_indicator_status(struct hotplug_slot *h_slot, u8 status); int pciehp_get_raw_indicator_status(struct hotplug_slot *h_slot, u8 *status); +int pciehp_slot_reset(struct pcie_device *dev); + static inline const char *slot_name(struct controller *ctrl) { return hotplug_slot_name(&ctrl->hotplug_slot); diff --git a/drivers/pci/hotplug/pciehp_core.c b/drivers/pci/hotplug/pciehp_core.c index ad3393930ecb..f34114d45259 100644 --- a/drivers/pci/hotplug/pciehp_core.c +++ b/drivers/pci/hotplug/pciehp_core.c @@ -351,6 +351,8 @@ static struct pcie_port_service_driver hpdriver_portdrv = { .runtime_suspend = pciehp_runtime_suspend, .runtime_resume = pciehp_runtime_resume, #endif /* PM */ + + .slot_reset = pciehp_slot_reset, }; int __init pcie_hp_init(void) diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c index 3024d7e85e6a..83a0fa119cae 100644 --- a/drivers/pci/hotplug/pciehp_hpc.c +++ b/drivers/pci/hotplug/pciehp_hpc.c @@ -862,6 +862,32 @@ void pcie_disable_interrupt(struct controller *ctrl) pcie_write_cmd(ctrl, 0, mask); } +/** + * pciehp_slot_reset() - ignore link event caused by error-induced hot reset + * @dev: PCI Express port service device + * + * Called from pcie_portdrv_slot_reset() after AER or DPC initiated a reset + * further up in the hierarchy to recover from an error. The reset was + * propagated down to this hotplug port. Ignore the resulting link flap. + * If the link failed to retrain successfully, synthesize the ignored event. + * Surprise removal during reset is detected through Presence Detect Changed. + */ +int pciehp_slot_reset(struct pcie_device *dev) +{ + struct controller *ctrl = get_service_data(dev); + + if (ctrl->state != ON_STATE) + return 0; + + pcie_capability_write_word(dev->port, PCI_EXP_SLTSTA, + PCI_EXP_SLTSTA_DLLSC); + + if (!pciehp_check_link_active(ctrl)) + pciehp_request(ctrl, PCI_EXP_SLTSTA_DLLSC); + + return 0; +} + /* * pciehp has a 1:1 bus:slot relationship so we ultimately want a secondary * bus reset of the bridge, but at the same time we want to ensure that it is diff --git a/drivers/pci/pcie/portdrv.h b/drivers/pci/pcie/portdrv.h index 6126ee4676a7..41fe1ffd5907 100644 --- a/drivers/pci/pcie/portdrv.h +++ b/drivers/pci/pcie/portdrv.h @@ -85,6 +85,8 @@ struct pcie_port_service_driver { int (*runtime_suspend)(struct pcie_device *dev); int (*runtime_resume)(struct pcie_device *dev); + int (*slot_reset)(struct pcie_device *dev); + /* Device driver may resume normal operations */ void (*error_resume)(struct pci_dev *dev); diff --git a/drivers/pci/pcie/portdrv_pci.c b/drivers/pci/pcie/portdrv_pci.c index c7ff1eea225a..1af74c3d9d5d 100644 --- a/drivers/pci/pcie/portdrv_pci.c +++ b/drivers/pci/pcie/portdrv_pci.c @@ -160,6 +160,9 @@ static pci_ers_result_t pcie_portdrv_error_detected(struct pci_dev *dev, static pci_ers_result_t pcie_portdrv_slot_reset(struct pci_dev *dev) { + size_t off = offsetof(struct pcie_port_service_driver, slot_reset); + device_for_each_child(&dev->dev, &off, pcie_port_device_iter); + pci_restore_state(dev); pci_save_state(dev); return PCI_ERS_RESULT_RECOVERED;

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Linux-stable-mirror November 2021