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

[Shuai Xue]

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 at vger.kernel.org
Suggested-by: Lukas Wunner <lukas at wunner.de>
Signed-off-by: Shuai Xue <xueshuai at linux.alibaba.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 */
 #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 */
-- 
2.39.3