PCI: Clear PCI_STATUS when setting up device

We are seeing Master Abort bit is set on Intel I350 ethernet device and its
root port right after boot, probably happened during BIOS phase:

  00:06.0 PCI bridge [0604]: Intel Corporation Device [8086:464d] (rev 05) (prog-if 00 [Normal decode])
    Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort+ >SERR- <PERR- INTx-

  6e:00.0 Ethernet controller [0200]: Intel Corporation I350 Gigabit Network Connection [8086:1521] (rev 01)
    Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort+ >SERR- <PERR- INTx-

The Master Abort bit is cleared after S3.

Since there's no functional impact found, clear the PCI_STATUS to treat it
anew at setting up.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=215989
Link: https://lore.kernel.org/r/20220517043738.2308499-1-kai.heng.feng@canonical.com
Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 17a9699..414f659 100644 (file)
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1890,6 +1890,9 @@ int pci_setup_device(struct pci_dev *dev)
 
        dev->broken_intx_masking = pci_intx_mask_broken(dev);
 
+       /* Clear errors left from system firmware */
+       pci_write_config_word(dev, PCI_STATUS, 0xffff);
+
        switch (dev->hdr_type) {                    /* header type */
        case PCI_HEADER_TYPE_NORMAL:                /* standard header */
                if (class == PCI_CLASS_BRIDGE_PCI)