February 2025 - Linux-stable-mirror

[PATCH v9 05/13] drm/bridge: cdns-dsi: Wait for Clk and Data Lanes to be ready

by Aradhya Bhatia

From: Aradhya Bhatia <a-bhatia1(a)ti.com> Once the DSI Link and DSI Phy are initialized, the code needs to wait for Clk and Data Lanes to be ready, before continuing configuration. This is in accordance with the DSI Start-up procedure, found in the Technical Reference Manual of Texas Instrument's J721E SoC[0] which houses this DSI TX controller. If the previous bridge (or crtc/encoder) are configured pre-maturely, the input signal FIFO gets corrupt. This introduces a color-shift on the display. Allow the driver to wait for the clk and data lanes to get ready during DSI enable. [0]: See section 12.6.5.7.3 "Start-up Procedure" in J721E SoC TRM TRM Link: http://www.ti.com/lit/pdf/spruil1 Fixes: e19233955d9e ("drm/bridge: Add Cadence DSI driver") Cc: stable(a)vger.kernel.org Tested-by: Dominik Haller <d.haller(a)phytec.de> Reviewed-by: Tomi Valkeinen <tomi.valkeinen(a)ideasonboard.com> Signed-off-by: Aradhya Bhatia <a-bhatia1(a)ti.com> Signed-off-by: Aradhya Bhatia <aradhya.bhatia(a)linux.dev> --- drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c b/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c index 87921a748cdb..6a77ca36cb9d 100644 --- a/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c +++ b/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c @@ -769,7 +769,7 @@ static void cdns_dsi_bridge_enable(struct drm_bridge *bridge) struct phy_configure_opts_mipi_dphy *phy_cfg = &output->phy_opts.mipi_dphy; unsigned long tx_byte_period; struct cdns_dsi_cfg dsi_cfg; - u32 tmp, reg_wakeup, div; + u32 tmp, reg_wakeup, div, status; int nlanes; if (WARN_ON(pm_runtime_get_sync(dsi->base.dev) < 0)) @@ -786,6 +786,19 @@ static void cdns_dsi_bridge_enable(struct drm_bridge *bridge) cdns_dsi_hs_init(dsi); cdns_dsi_init_link(dsi); + /* + * Now that the DSI Link and DSI Phy are initialized, + * wait for the CLK and Data Lanes to be ready. + */ + tmp = CLK_LANE_RDY; + for (int i = 0; i < nlanes; i++) + tmp |= DATA_LANE_RDY(i); + + if (readl_poll_timeout(dsi->regs + MCTL_MAIN_STS, status, + (tmp == (status & tmp)), 100, 500000)) + dev_err(dsi->base.dev, + "Timed Out: DSI-DPhy Clock and Data Lanes not ready.\n"); + writel(HBP_LEN(dsi_cfg.hbp) | HSA_LEN(dsi_cfg.hsa), dsi->regs + VID_HSIZE1); writel(HFP_LEN(dsi_cfg.hfp) | HACT_LEN(dsi_cfg.hact), -- 2.34.1

4 months

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[PATCH v9 04/13] drm/bridge: cdns-dsi: Check return value when getting default PHY config

by Aradhya Bhatia

From: Aradhya Bhatia <a-bhatia1(a)ti.com> Check for the return value of the phy_mipi_dphy_get_default_config() call, and in case of an error, return back the same. Fixes: fced5a364dee ("drm/bridge: cdns: Convert to phy framework") Cc: stable(a)vger.kernel.org Reviewed-by: Tomi Valkeinen <tomi.valkeinen(a)ideasonboard.com> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov(a)linaro.org> Signed-off-by: Aradhya Bhatia <a-bhatia1(a)ti.com> Signed-off-by: Aradhya Bhatia <aradhya.bhatia(a)linux.dev> --- drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c b/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c index 19cc8734a4c8..87921a748cdb 100644 --- a/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c +++ b/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c @@ -575,9 +575,11 @@ static int cdns_dsi_check_conf(struct cdns_dsi *dsi, if (ret) return ret; - phy_mipi_dphy_get_default_config(mode_clock * 1000, - mipi_dsi_pixel_format_to_bpp(output->dev->format), - nlanes, phy_cfg); + ret = phy_mipi_dphy_get_default_config(mode_clock * 1000, + mipi_dsi_pixel_format_to_bpp(output->dev->format), + nlanes, phy_cfg); + if (ret) + return ret; ret = cdns_dsi_adjust_phy_config(dsi, dsi_cfg, phy_cfg, mode, mode_valid_check); if (ret) -- 2.34.1

4 months

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[PATCH v9 03/13] drm/bridge: cdns-dsi: Fix the clock variable for mode_valid()

by Aradhya Bhatia

From: Aradhya Bhatia <a-bhatia1(a)ti.com> The crtc_* mode parameters do not get generated (duplicated in this case) from the regular parameters before the mode validation phase begins. The rest of the code conditionally uses the crtc_* parameters only during the bridge enable phase, but sticks to the regular parameters for mode validation. In this singular instance, however, the driver tries to use the crtc_clock parameter even during the mode validation, causing the validation to fail. Allow the D-Phy config checks to use mode->clock instead of mode->crtc_clock during mode_valid checks, like everywhere else in the driver. Fixes: fced5a364dee ("drm/bridge: cdns: Convert to phy framework") Cc: stable(a)vger.kernel.org Reviewed-by: Tomi Valkeinen <tomi.valkeinen(a)ideasonboard.com> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov(a)linaro.org> Signed-off-by: Aradhya Bhatia <a-bhatia1(a)ti.com> Signed-off-by: Aradhya Bhatia <aradhya.bhatia(a)linux.dev> --- drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c b/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c index b0a1a6774ea6..19cc8734a4c8 100644 --- a/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c +++ b/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c @@ -568,13 +568,14 @@ static int cdns_dsi_check_conf(struct cdns_dsi *dsi, struct phy_configure_opts_mipi_dphy *phy_cfg = &output->phy_opts.mipi_dphy; unsigned long dsi_hss_hsa_hse_hbp; unsigned int nlanes = output->dev->lanes; + int mode_clock = (mode_valid_check ? mode->clock : mode->crtc_clock); int ret; ret = cdns_dsi_mode2cfg(dsi, mode, dsi_cfg, mode_valid_check); if (ret) return ret; - phy_mipi_dphy_get_default_config(mode->crtc_clock * 1000, + phy_mipi_dphy_get_default_config(mode_clock * 1000, mipi_dsi_pixel_format_to_bpp(output->dev->format), nlanes, phy_cfg); -- 2.34.1

4 months

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[PATCH v9 02/13] drm/bridge: cdns-dsi: Fix phy de-init and flag it so

by Aradhya Bhatia

From: Aradhya Bhatia <a-bhatia1(a)ti.com> The driver code doesn't have a Phy de-initialization path as yet, and so it does not clear the phy_initialized flag while suspending. This is a problem because after resume the driver looks at this flag to determine if a Phy re-initialization is required or not. It is in fact required because the hardware is resuming from a suspend, but the driver does not carry out any re-initialization causing the D-Phy to not work at all. Call the counterparts of phy_init() and phy_power_on(), that are phy_exit() and phy_power_off(), from _bridge_post_disable(), and clear the flags so that the Phy can be initialized again when required. Fixes: fced5a364dee ("drm/bridge: cdns: Convert to phy framework") Cc: stable(a)vger.kernel.org Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov(a)linaro.org> Reviewed-by: Tomi Valkeinen <tomi.valkeinen(a)ideasonboard.com> Signed-off-by: Aradhya Bhatia <a-bhatia1(a)ti.com> Signed-off-by: Aradhya Bhatia <aradhya.bhatia(a)linux.dev> --- drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c b/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c index 2f897ea5e80a..b0a1a6774ea6 100644 --- a/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c +++ b/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c @@ -680,6 +680,11 @@ static void cdns_dsi_bridge_post_disable(struct drm_bridge *bridge) struct cdns_dsi_input *input = bridge_to_cdns_dsi_input(bridge); struct cdns_dsi *dsi = input_to_dsi(input); + dsi->phy_initialized = false; + dsi->link_initialized = false; + phy_power_off(dsi->dphy); + phy_exit(dsi->dphy); + pm_runtime_put(dsi->base.dev); } @@ -1152,7 +1157,6 @@ static int __maybe_unused cdns_dsi_suspend(struct device *dev) clk_disable_unprepare(dsi->dsi_sys_clk); clk_disable_unprepare(dsi->dsi_p_clk); reset_control_assert(dsi->dsi_p_rst); - dsi->link_initialized = false; return 0; } -- 2.34.1

4 months

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[PATCH v9 01/13] drm/bridge: cdns-dsi: Fix connecting to next bridge

by Aradhya Bhatia

From: Aradhya Bhatia <a-bhatia1(a)ti.com> Fix the OF node pointer passed to the of_drm_find_bridge() call to find the next bridge in the display chain. The code to find the next panel (and create its panel-bridge) works fine, but to find the next (non-panel) bridge does not. To find the next bridge in the pipeline, we need to pass "np" - the OF node pointer of the next entity in the devicetree chain. Passing "of_node" to of_drm_find_bridge (which is what the code does currently) will fetch the bridge for the cdns-dsi which is not what's required. Fix that. Fixes: e19233955d9e ("drm/bridge: Add Cadence DSI driver") Cc: stable(a)vger.kernel.org Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov(a)linaro.org> Reviewed-by: Tomi Valkeinen <tomi.valkeinen(a)ideasonboard.com> Signed-off-by: Aradhya Bhatia <a-bhatia1(a)ti.com> Signed-off-by: Aradhya Bhatia <aradhya.bhatia(a)linux.dev> --- drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c b/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c index c7a0247e06ad..2f897ea5e80a 100644 --- a/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c +++ b/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c @@ -952,7 +952,7 @@ static int cdns_dsi_attach(struct mipi_dsi_host *host, bridge = drm_panel_bridge_add_typed(panel, DRM_MODE_CONNECTOR_DSI); } else { - bridge = of_drm_find_bridge(dev->dev.of_node); + bridge = of_drm_find_bridge(np); if (!bridge) bridge = ERR_PTR(-EINVAL); } -- 2.34.1

4 months

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[char-misc] mei: me: add panther lake P DID

by Alexander Usyskin

Add Panther Lake P device id. Cc: <stable(a)vger.kernel.org> Co-developed-by: Tomas Winkler <tomasw(a)gmail.com> Signed-off-by: Tomas Winkler <tomasw(a)gmail.com> Signed-off-by: Alexander Usyskin <alexander.usyskin(a)intel.com> --- drivers/misc/mei/hw-me-regs.h | 2 ++ drivers/misc/mei/pci-me.c | 2 ++ 2 files changed, 4 insertions(+) diff --git a/drivers/misc/mei/hw-me-regs.h b/drivers/misc/mei/hw-me-regs.h index c3a6657dcd4a..a5f88ec97df7 100644 --- a/drivers/misc/mei/hw-me-regs.h +++ b/drivers/misc/mei/hw-me-regs.h @@ -117,6 +117,8 @@ #define MEI_DEV_ID_LNL_M 0xA870 /* Lunar Lake Point M */ +#define MEI_DEV_ID_PTL_P 0xE470 /* Panther Lake P */ + /* * MEI HW Section */ diff --git a/drivers/misc/mei/pci-me.c b/drivers/misc/mei/pci-me.c index 6589635f8ba3..d6ff9d82ae94 100644 --- a/drivers/misc/mei/pci-me.c +++ b/drivers/misc/mei/pci-me.c @@ -124,6 +124,8 @@ static const struct pci_device_id mei_me_pci_tbl[] = { {MEI_PCI_DEVICE(MEI_DEV_ID_LNL_M, MEI_ME_PCH15_CFG)}, + {MEI_PCI_DEVICE(MEI_DEV_ID_PTL_P, MEI_ME_PCH15_CFG)}, + /* required last entry */ {0, } }; -- 2.43.0

4 months

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[PATCH] crypto: ccp - Fix check for the primary ASP device

by Tom Lendacky

Currently, the ASP primary device check does not have support for PCI domains, and, as a result, when the system is configured with PCI domains (PCI segments) the wrong device can be selected as primary. This results in commands submitted to the device timing out and failing. The device check also relies on specific device and function assignments that may not hold in the future. Fix the primary ASP device check to include support for PCI domains and to perform proper checking of the Bus/Device/Function positions. Fixes: 2a6170dfe755 ("crypto: ccp: Add Platform Security Processor (PSP) device support") Cc: stable(a)vger.kernel.org Signed-off-by: Tom Lendacky <thomas.lendacky(a)amd.com> --- drivers/crypto/ccp/sp-pci.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) diff --git a/drivers/crypto/ccp/sp-pci.c b/drivers/crypto/ccp/sp-pci.c index 248d98fd8c48..157f9a9ed636 100644 --- a/drivers/crypto/ccp/sp-pci.c +++ b/drivers/crypto/ccp/sp-pci.c @@ -189,14 +189,17 @@ static bool sp_pci_is_master(struct sp_device *sp) pdev_new = to_pci_dev(dev_new); pdev_cur = to_pci_dev(dev_cur); - if (pdev_new->bus->number < pdev_cur->bus->number) - return true; + if (pci_domain_nr(pdev_new->bus) != pci_domain_nr(pdev_cur->bus)) + return pci_domain_nr(pdev_new->bus) < pci_domain_nr(pdev_cur->bus); - if (PCI_SLOT(pdev_new->devfn) < PCI_SLOT(pdev_cur->devfn)) - return true; + if (pdev_new->bus->number != pdev_cur->bus->number) + return pdev_new->bus->number < pdev_cur->bus->number; - if (PCI_FUNC(pdev_new->devfn) < PCI_FUNC(pdev_cur->devfn)) - return true; + if (PCI_SLOT(pdev_new->devfn) != PCI_SLOT(pdev_cur->devfn)) + return PCI_SLOT(pdev_new->devfn) < PCI_SLOT(pdev_cur->devfn); + + if (PCI_FUNC(pdev_new->devfn) != PCI_FUNC(pdev_cur->devfn)) + return PCI_FUNC(pdev_new->devfn) < PCI_FUNC(pdev_cur->devfn); return false; } base-commit: cd26cd65476711e2c69e0a049c0eeef4b743f5ac -- 2.46.2

4 months

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FAILED: patch "[PATCH] tty: xilinx_uartps: split sysrq handling" 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>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y git checkout FETCH_HEAD git cherry-pick -x b06f388994500297bb91be60ffaf6825ecfd2afe # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025020900-irritate-payphone-afbb@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From b06f388994500297bb91be60ffaf6825ecfd2afe Mon Sep 17 00:00:00 2001 From: Sean Anderson <sean.anderson(a)linux.dev> Date: Fri, 10 Jan 2025 16:38:22 -0500 Subject: [PATCH] tty: xilinx_uartps: split sysrq handling lockdep detects the following circular locking dependency: CPU 0 CPU 1 ========================== ============================ cdns_uart_isr() printk() uart_port_lock(port) console_lock() cdns_uart_console_write() if (!port->sysrq) uart_port_lock(port) uart_handle_break() port->sysrq = ... uart_handle_sysrq_char() printk() console_lock() The fixed commit attempts to avoid this situation by only taking the port lock in cdns_uart_console_write if port->sysrq unset. However, if (as shown above) cdns_uart_console_write runs before port->sysrq is set, then it will try to take the port lock anyway. This may result in a deadlock. Fix this by splitting sysrq handling into two parts. We use the prepare helper under the port lock and defer handling until we release the lock. Fixes: 74ea66d4ca06 ("tty: xuartps: Improve sysrq handling") Signed-off-by: Sean Anderson <sean.anderson(a)linux.dev> Cc: stable(a)vger.kernel.org # c980248179d: serial: xilinx_uartps: Use port lock wrappers Acked-by: John Ogness <john.ogness(a)linutronix.de> Link: https://lore.kernel.org/r/20250110213822.2107462-1-sean.anderson@linux.dev Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c index beb151be4d32..92ec51870d1d 100644 --- a/drivers/tty/serial/xilinx_uartps.c +++ b/drivers/tty/serial/xilinx_uartps.c @@ -287,7 +287,7 @@ static void cdns_uart_handle_rx(void *dev_id, unsigned int isrstatus) continue; } - if (uart_handle_sysrq_char(port, data)) + if (uart_prepare_sysrq_char(port, data)) continue; if (is_rxbs_support) { @@ -495,7 +495,7 @@ static irqreturn_t cdns_uart_isr(int irq, void *dev_id) !(readl(port->membase + CDNS_UART_CR) & CDNS_UART_CR_RX_DIS)) cdns_uart_handle_rx(dev_id, isrstatus); - uart_port_unlock(port); + uart_unlock_and_check_sysrq(port); return IRQ_HANDLED; } @@ -1380,9 +1380,7 @@ static void cdns_uart_console_write(struct console *co, const char *s, unsigned int imr, ctrl; int locked = 1; - if (port->sysrq) - locked = 0; - else if (oops_in_progress) + if (oops_in_progress) locked = uart_port_trylock_irqsave(port, &flags); else uart_port_lock_irqsave(port, &flags);

4 months

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FAILED: patch "[PATCH] tty: xilinx_uartps: split sysrq handling" failed to apply to 5.10-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.10-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>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y git checkout FETCH_HEAD git cherry-pick -x b06f388994500297bb91be60ffaf6825ecfd2afe # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025020957-proofs-smilingly-7fac@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From b06f388994500297bb91be60ffaf6825ecfd2afe Mon Sep 17 00:00:00 2001 From: Sean Anderson <sean.anderson(a)linux.dev> Date: Fri, 10 Jan 2025 16:38:22 -0500 Subject: [PATCH] tty: xilinx_uartps: split sysrq handling lockdep detects the following circular locking dependency: CPU 0 CPU 1 ========================== ============================ cdns_uart_isr() printk() uart_port_lock(port) console_lock() cdns_uart_console_write() if (!port->sysrq) uart_port_lock(port) uart_handle_break() port->sysrq = ... uart_handle_sysrq_char() printk() console_lock() The fixed commit attempts to avoid this situation by only taking the port lock in cdns_uart_console_write if port->sysrq unset. However, if (as shown above) cdns_uart_console_write runs before port->sysrq is set, then it will try to take the port lock anyway. This may result in a deadlock. Fix this by splitting sysrq handling into two parts. We use the prepare helper under the port lock and defer handling until we release the lock. Fixes: 74ea66d4ca06 ("tty: xuartps: Improve sysrq handling") Signed-off-by: Sean Anderson <sean.anderson(a)linux.dev> Cc: stable(a)vger.kernel.org # c980248179d: serial: xilinx_uartps: Use port lock wrappers Acked-by: John Ogness <john.ogness(a)linutronix.de> Link: https://lore.kernel.org/r/20250110213822.2107462-1-sean.anderson@linux.dev Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c index beb151be4d32..92ec51870d1d 100644 --- a/drivers/tty/serial/xilinx_uartps.c +++ b/drivers/tty/serial/xilinx_uartps.c @@ -287,7 +287,7 @@ static void cdns_uart_handle_rx(void *dev_id, unsigned int isrstatus) continue; } - if (uart_handle_sysrq_char(port, data)) + if (uart_prepare_sysrq_char(port, data)) continue; if (is_rxbs_support) { @@ -495,7 +495,7 @@ static irqreturn_t cdns_uart_isr(int irq, void *dev_id) !(readl(port->membase + CDNS_UART_CR) & CDNS_UART_CR_RX_DIS)) cdns_uart_handle_rx(dev_id, isrstatus); - uart_port_unlock(port); + uart_unlock_and_check_sysrq(port); return IRQ_HANDLED; } @@ -1380,9 +1380,7 @@ static void cdns_uart_console_write(struct console *co, const char *s, unsigned int imr, ctrl; int locked = 1; - if (port->sysrq) - locked = 0; - else if (oops_in_progress) + if (oops_in_progress) locked = uart_port_trylock_irqsave(port, &flags); else uart_port_lock_irqsave(port, &flags);

4 months

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FAILED: patch "[PATCH] tty: xilinx_uartps: split sysrq handling" failed to apply to 5.15-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.15-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>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y git checkout FETCH_HEAD git cherry-pick -x b06f388994500297bb91be60ffaf6825ecfd2afe # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025020955-handbook-simplify-cf71@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From b06f388994500297bb91be60ffaf6825ecfd2afe Mon Sep 17 00:00:00 2001 From: Sean Anderson <sean.anderson(a)linux.dev> Date: Fri, 10 Jan 2025 16:38:22 -0500 Subject: [PATCH] tty: xilinx_uartps: split sysrq handling lockdep detects the following circular locking dependency: CPU 0 CPU 1 ========================== ============================ cdns_uart_isr() printk() uart_port_lock(port) console_lock() cdns_uart_console_write() if (!port->sysrq) uart_port_lock(port) uart_handle_break() port->sysrq = ... uart_handle_sysrq_char() printk() console_lock() The fixed commit attempts to avoid this situation by only taking the port lock in cdns_uart_console_write if port->sysrq unset. However, if (as shown above) cdns_uart_console_write runs before port->sysrq is set, then it will try to take the port lock anyway. This may result in a deadlock. Fix this by splitting sysrq handling into two parts. We use the prepare helper under the port lock and defer handling until we release the lock. Fixes: 74ea66d4ca06 ("tty: xuartps: Improve sysrq handling") Signed-off-by: Sean Anderson <sean.anderson(a)linux.dev> Cc: stable(a)vger.kernel.org # c980248179d: serial: xilinx_uartps: Use port lock wrappers Acked-by: John Ogness <john.ogness(a)linutronix.de> Link: https://lore.kernel.org/r/20250110213822.2107462-1-sean.anderson@linux.dev Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c index beb151be4d32..92ec51870d1d 100644 --- a/drivers/tty/serial/xilinx_uartps.c +++ b/drivers/tty/serial/xilinx_uartps.c @@ -287,7 +287,7 @@ static void cdns_uart_handle_rx(void *dev_id, unsigned int isrstatus) continue; } - if (uart_handle_sysrq_char(port, data)) + if (uart_prepare_sysrq_char(port, data)) continue; if (is_rxbs_support) { @@ -495,7 +495,7 @@ static irqreturn_t cdns_uart_isr(int irq, void *dev_id) !(readl(port->membase + CDNS_UART_CR) & CDNS_UART_CR_RX_DIS)) cdns_uart_handle_rx(dev_id, isrstatus); - uart_port_unlock(port); + uart_unlock_and_check_sysrq(port); return IRQ_HANDLED; } @@ -1380,9 +1380,7 @@ static void cdns_uart_console_write(struct console *co, const char *s, unsigned int imr, ctrl; int locked = 1; - if (port->sysrq) - locked = 0; - else if (oops_in_progress) + if (oops_in_progress) locked = uart_port_trylock_irqsave(port, &flags); else uart_port_lock_irqsave(port, &flags);

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Linux-stable-mirror February 2025