[PATCH v2 1/1] PCI/RCEC: Fix RCiEP capable devices RCEC association

[Qiuxu Zhuo]

Function rcec_assoc_rciep() incorrectly used "rciep->devfn" (a single
byte encoding the device and function number) as the device number to
check whether the corresponding bit was set in the RCiEPBitmap of the
RCEC (Root Complex Event Collector) while enumerating over each bit of
the RCiEPBitmap.

As per the PCI Express Base Specification, Revision 5.0, Version 1.0,
Section 7.9.10.2, "Association Bitmap for RCiEPs", p. 935, only needs to
use a device number to check whether the corresponding bit was set in
the RCiEPBitmap.

Fix rcec_assoc_rciep() using the PCI_SLOT() macro and convert the value
of "rciep->devfn" to a device number to ensure that the RCiEP devices
associated with the RCEC are linked when the RCEC is enumerated.

[ Krzysztof: Update commit message. ]

Fixes: 507b460f8144 ("PCI/ERR: Add pcie_link_rcec() to associate RCiEPs")
Reported-and-tested-by: Wen Jin <wen.jin@xxxxxxxxx>
Reviewed-by: Sean V Kelley <sean.v.kelley@xxxxxxxxx>
Signed-off-by: Qiuxu Zhuo <qiuxu.zhuo@xxxxxxxxx>
---
v1->v2:
  - Update the subject and the commit message.
  - Add 'Reviewed-by: Sean V Kelley <sean.v.kelley@xxxxxxxxx>' to the SoB chain.

 drivers/pci/pcie/rcec.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/pci/pcie/rcec.c b/drivers/pci/pcie/rcec.c
index 2c5c552994e4..d0bcd141ac9c 100644
--- a/drivers/pci/pcie/rcec.c
+++ b/drivers/pci/pcie/rcec.c
@@ -32,7 +32,7 @@ static bool rcec_assoc_rciep(struct pci_dev *rcec, struct pci_dev *rciep)
 
 	/* Same bus, so check bitmap */
 	for_each_set_bit(devn, &bitmap, 32)
-		if (devn == rciep->devfn)
+		if (devn == PCI_SLOT(rciep->devfn))
 			return true;
 
 	return false;
-- 
2.17.1