Ever since introduction in the commit 0c8173385e54 ("rtl8192ce: Add new driver") the rtlwifi code has, according to comments, attempted to disable/enable ASPM of the upstream bridge by writing into its LNKCTL register. However, the code has never been correct because it performs the writes to the device instead of the upstream bridge.

Worse yet, the offset where the PCIe capabilities reside is derived from the offset of the upstream bridge. As a result, the write will use an offset on the device that does not relate to the LNKCTL register making the ASPM disable/enable code outright dangerous.

Because of those problems, there is no indication that the driver needs disable/enable ASPM on the upstream bridge. As the Capabilities offset is not correctly calculated for the write to target device's LNKCTL register, the code is not disabling/enabling device's ASPM either. Therefore, just remove the upstream bridge related ASPM disable/enable code entirely.

The upstream bridge related ASPM code was the only user of the struct mp_adapter members num4bytes, pcibridge_pciehdr_offset, and pcibridge_linkctrlreg so those are removed as well.

Note: This change does not remove the code related to changing the device's ASPM on purpose (which is independent of this flawed code related to upstream bridge's ASPM).

Suggested-by: Bjorn Helgaas bhelgaas@kernel.org Fixes: 0c8173385e54 ("rtl8192ce: Add new driver") Fixes: 886e14b65a8f ("rtlwifi: Eliminate raw reads and writes from PCIe portion") Cc: stable@vger.kernel.org Signed-off-by: Ilpo Järvinen ilpo.jarvinen@linux.intel.com --- drivers/net/wireless/realtek/rtlwifi/pci.c | 58 +--------------------- drivers/net/wireless/realtek/rtlwifi/pci.h | 5 -- 2 files changed, 1 insertion(+), 62 deletions(-)

diff --git a/drivers/net/wireless/realtek/rtlwifi/pci.c b/drivers/net/wireless/realtek/rtlwifi/pci.c index 9886e719739b..206eca310cd7 100644 --- a/drivers/net/wireless/realtek/rtlwifi/pci.c +++ b/drivers/net/wireless/realtek/rtlwifi/pci.c @@ -192,11 +192,8 @@ static void rtl_pci_disable_aspm(struct ieee80211_hw *hw) struct rtl_ps_ctl *ppsc = rtl_psc(rtl_priv(hw)); struct rtl_pci *rtlpci = rtl_pcidev(rtl_pcipriv(hw)); u8 pcibridge_vendor = pcipriv->ndis_adapter.pcibridge_vendor; - u8 num4bytes = pcipriv->ndis_adapter.num4bytes; /*Retrieve original configuration settings. */ u8 linkctrl_reg = pcipriv->ndis_adapter.linkctrl_reg; - u16 pcibridge_linkctrlreg = pcipriv->ndis_adapter. - pcibridge_linkctrlreg; u16 aspmlevel = 0; u8 tmp_u1b = 0;

@@ -221,16 +218,8 @@ static void rtl_pci_disable_aspm(struct ieee80211_hw *hw) /*Set corresponding value. */ aspmlevel |= BIT(0) | BIT(1); linkctrl_reg &= ~aspmlevel; - pcibridge_linkctrlreg &= ~(BIT(0) | BIT(1));

_rtl_pci_platform_switch_device_pci_aspm(hw, linkctrl_reg); - udelay(50); - - /*4 Disable Pci Bridge ASPM */ - pci_write_config_byte(rtlpci->pdev, (num4bytes << 2), - pcibridge_linkctrlreg); - - udelay(50); }

/*Enable RTL8192SE ASPM & Enable Pci Bridge ASPM for @@ -245,9 +234,7 @@ static void rtl_pci_enable_aspm(struct ieee80211_hw *hw) struct rtl_ps_ctl *ppsc = rtl_psc(rtl_priv(hw)); struct rtl_pci *rtlpci = rtl_pcidev(rtl_pcipriv(hw)); u8 pcibridge_vendor = pcipriv->ndis_adapter.pcibridge_vendor; - u8 num4bytes = pcipriv->ndis_adapter.num4bytes; u16 aspmlevel; - u8 u_pcibridge_aspmsetting; u8 u_device_aspmsetting;

if (!ppsc->support_aspm) @@ -259,25 +246,6 @@ static void rtl_pci_enable_aspm(struct ieee80211_hw *hw) return; }

- /*4 Enable Pci Bridge ASPM */ - - u_pcibridge_aspmsetting = - pcipriv->ndis_adapter.pcibridge_linkctrlreg | - rtlpci->const_hostpci_aspm_setting; - - if (pcibridge_vendor == PCI_BRIDGE_VENDOR_INTEL) - u_pcibridge_aspmsetting &= ~BIT(0); - - pci_write_config_byte(rtlpci->pdev, (num4bytes << 2), - u_pcibridge_aspmsetting); - - rtl_dbg(rtlpriv, COMP_INIT, DBG_LOUD, - "PlatformEnableASPM(): Write reg[%x] = %x\n", - (pcipriv->ndis_adapter.pcibridge_pciehdr_offset + 0x10), - u_pcibridge_aspmsetting); - - udelay(50); - /*Get ASPM level (with/without Clock Req) */ aspmlevel = rtlpci->const_devicepci_aspm_setting; u_device_aspmsetting = pcipriv->ndis_adapter.linkctrl_reg; @@ -358,22 +326,6 @@ static bool rtl_pci_check_buddy_priv(struct ieee80211_hw *hw, return tpriv != NULL; }

-static void rtl_pci_get_linkcontrol_field(struct ieee80211_hw *hw) -{ - struct rtl_pci_priv *pcipriv = rtl_pcipriv(hw); - struct rtl_pci *rtlpci = rtl_pcidev(pcipriv); - u8 capabilityoffset = pcipriv->ndis_adapter.pcibridge_pciehdr_offset; - u8 linkctrl_reg; - u8 num4bbytes; - - num4bbytes = (capabilityoffset + 0x10) / 4; - - /*Read Link Control Register */ - pci_read_config_byte(rtlpci->pdev, (num4bbytes << 2), &linkctrl_reg); - - pcipriv->ndis_adapter.pcibridge_linkctrlreg = linkctrl_reg; -} - static void rtl_pci_parse_configuration(struct pci_dev *pdev, struct ieee80211_hw *hw) { @@ -2028,12 +1980,6 @@ static bool _rtl_pci_find_adapter(struct pci_dev *pdev, PCI_SLOT(bridge_pdev->devfn); pcipriv->ndis_adapter.pcibridge_funcnum = PCI_FUNC(bridge_pdev->devfn); - pcipriv->ndis_adapter.pcibridge_pciehdr_offset = - pci_pcie_cap(bridge_pdev); - pcipriv->ndis_adapter.num4bytes = - (pcipriv->ndis_adapter.pcibridge_pciehdr_offset + 0x10) / 4; - - rtl_pci_get_linkcontrol_field(hw);

if (pcipriv->ndis_adapter.pcibridge_vendor == PCI_BRIDGE_VENDOR_AMD) { @@ -2050,13 +1996,11 @@ static bool _rtl_pci_find_adapter(struct pci_dev *pdev, pdev->vendor, pcipriv->ndis_adapter.linkctrl_reg);

rtl_dbg(rtlpriv, COMP_INIT, DBG_DMESG, - "pci_bridge busnumber:devnumber:funcnumber:vendor:pcie_cap:link_ctl_reg:amd %d:%d:%d:%x:%x:%x:%x\n", + "pci_bridge busnumber:devnumber:funcnumber:vendor:amd %d:%d:%d:%x:%x\n", pcipriv->ndis_adapter.pcibridge_busnum, pcipriv->ndis_adapter.pcibridge_devnum, pcipriv->ndis_adapter.pcibridge_funcnum, pcibridge_vendors[pcipriv->ndis_adapter.pcibridge_vendor], - pcipriv->ndis_adapter.pcibridge_pciehdr_offset, - pcipriv->ndis_adapter.pcibridge_linkctrlreg, pcipriv->ndis_adapter.amd_l1_patch);

rtl_pci_parse_configuration(pdev, hw); diff --git a/drivers/net/wireless/realtek/rtlwifi/pci.h b/drivers/net/wireless/realtek/rtlwifi/pci.h index 866861626a0a..d6307197dfea 100644 --- a/drivers/net/wireless/realtek/rtlwifi/pci.h +++ b/drivers/net/wireless/realtek/rtlwifi/pci.h @@ -236,11 +236,6 @@ struct mp_adapter { u16 pcibridge_vendorid; u16 pcibridge_deviceid;

- u8 num4bytes; - - u8 pcibridge_pciehdr_offset; - u8 pcibridge_linkctrlreg; - bool amd_l1_patch; };