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

[Kuppuswamy Sathyanarayanan]

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@xxxxxxxxxxxxxxx
> Suggested-by: Lukas Wunner <lukas@xxxxxxxxx>
> Signed-off-by: Shuai Xue <xueshuai@xxxxxxxxxxxxxxxxx>
> ---

Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx>


>  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