Re: [PATCH v7 5/5] PCI/AER: Only clear error bits in pcie_clear_device_status()

Kuppuswamy Sathyanarayanan
2026-01-28T17:01:22Z

On 1/23/2026 11:45 PM, Shuai Xue wrote:
> Currently, pcie_clear_device_status() clears the entire PCIe Device
> Status register (PCI_EXP_DEVSTA), which includes both error status bits
> and other status bits such as AUX Power Detected (AUXPD) and
> Transactions Pending (TRPND).
>
> Clearing non-error status bits can interfere with other drivers or
> subsystems that may rely on these bits. To fix it, only clear the error
> bits (0xf) while preserving other status bits.
>
> Fixes: ec752f5d54d7 ("PCI/AER: Clear device status bits during ERR_FATAL and ERR_NONFATAL")
> Cc: stable@vger.kernel.org
> Suggested-by: Lukas Wunner <lukas@wunner.de>
> Signed-off-by: Shuai Xue <xueshuai@linux.alibaba.com>
> ---

Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>

> drivers/pci/pci.c | 2 +-
> include/uapi/linux/pci_regs.h | 1 +
> 2 files changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> index 13dbb405dc31..0b947f90c333 100644
> --- a/drivers/pci/pci.c
> +++ b/drivers/pci/pci.c
> @@ -2246,7 +2246,7 @@ void pcie_clear_device_status(struct pci_dev *dev)
> u16 sta;
>
> pcie_capability_read_word(dev, PCI_EXP_DEVSTA, &sta);
> - pcie_capability_write_word(dev, PCI_EXP_DEVSTA, sta);
> + pcie_capability_write_word(dev, PCI_EXP_DEVSTA, sta & PCI_EXP_DEVSTA_ERR);
> }
> #endif
>
> diff --git a/include/uapi/linux/pci_regs.h b/include/uapi/linux/pci_regs.h
> index 3add74ae2594..f4b68203bc4e 100644
> --- a/include/uapi/linux/pci_regs.h
> +++ b/include/uapi/linux/pci_regs.h
> @@ -534,6 +534,7 @@
> #define PCI_EXP_DEVSTA_NFED 0x0002 /* Non-Fatal Error Detected */
> #define PCI_EXP_DEVSTA_FED 0x0004 /* Fatal Error Detected */
> #define PCI_EXP_DEVSTA_URD 0x0008 /* Unsupported Request Detected */
> +#define PCI_EXP_DEVSTA_ERR 0xf /* Error bits */

To align with other macros, use 0x000F?

> #define PCI_EXP_DEVSTA_AUXPD 0x0010 /* AUX Power Detected */
> #define PCI_EXP_DEVSTA_TRPND 0x0020 /* Transactions Pending */
> #define PCI_CAP_EXP_RC_ENDPOINT_SIZEOF_V1 12 /* v1 endpoints without link end here */

--
Sathyanarayanan Kuppuswamy
Linux Kernel Developer