diff options
| author | Shuai Xue <xueshuai@linux.alibaba.com> | 2026-02-11 15:46:24 +0300 |
|---|---|---|
| committer | Bjorn Helgaas <bhelgaas@google.com> | 2026-02-23 18:00:33 +0300 |
| commit | a8aeea1bf3c80cc87983689e0118770e019bd4f3 (patch) | |
| tree | de9fc7242bf5743c944af8dfcc893c97589f371b | |
| parent | 6de23f81a5e08be8fbf5e8d7e9febc72a5b5f27f (diff) | |
| download | linux-a8aeea1bf3c80cc87983689e0118770e019bd4f3.tar.xz | |
PCI/AER: Clear only error bits in PCIe Device Status
Currently, pcie_clear_device_status() clears the entire PCIe Device Status
register (PCI_EXP_DEVSTA) by writing back the value read from the register,
which affects not only the error status bits but also other writable bits.
According to PCIe r7.0, sec 7.5.3.5, this register contains:
- RW1C error status bits (CED, NFED, FED, URD at bits 0-3): These are the
four error status bits that need to be cleared.
- Read-only bits (AUXPD at bit 4, TRPND at bit 5): Writing to these has
no effect.
- Emergency Power Reduction Detected (bit 6): A RW1C non-error bit
introduced in PCIe r5.0 (2019). This is currently the only writable
non-error bit in the Device Status register. Unconditionally clearing
this bit can interfere with other software components that rely on this
power management indication.
- Reserved bits (RsvdZ): These bits are required to be written as zero.
Writing 1s to them (as the current implementation may do) violates the
specification.
To prevent unintended side effects, modify pcie_clear_device_status() to
only write 1s to the four error status bits (CED, NFED, FED, URD), leaving
the Emergency Power Reduction Detected bit and reserved bits unaffected.
Fixes: ec752f5d54d7 ("PCI/AER: Clear device status bits during ERR_FATAL and ERR_NONFATAL")
Suggested-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Shuai Xue <xueshuai@linux.alibaba.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Reviewed-by: Lukas Wunner <lukas@wunner.de>
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260211124624.49656-1-xueshuai@linux.alibaba.com
| -rw-r--r-- | drivers/pci/pci.c | 7 |
1 files changed, 3 insertions, 4 deletions
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 8479c2e1f74f..8e3e4e24c909 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -2241,10 +2241,9 @@ EXPORT_SYMBOL_GPL(pci_set_pcie_reset_state); #ifdef CONFIG_PCIEAER 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, + PCI_EXP_DEVSTA_CED | PCI_EXP_DEVSTA_NFED | + PCI_EXP_DEVSTA_FED | PCI_EXP_DEVSTA_URD); } #endif |