RE: [PATCH v3 1/1] PCI/RCEC: Fix RCiEP capable devices RCEC association

[Zhuo, Qiuxu]

Hi Bjorn,

Do you have any comments on this patch? If need any changes, please let me know. 
Thanks!

-Qiuxu

> -----Original Message-----
> From: Zhuo, Qiuxu <qiuxu.zhuo@xxxxxxxxx>
> Sent: Monday, February 22, 2021 9:17 AM
> To: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
> Cc: Zhuo, Qiuxu <qiuxu.zhuo@xxxxxxxxx>; Lorenzo Pieralisi
> <lorenzo.pieralisi@xxxxxxx>; Krzysztof Wilczyński <kw@xxxxxxxxx>; Kelley,
> Sean V <sean.v.kelley@xxxxxxxxx>; Luck, Tony <tony.luck@xxxxxxxxx>; Jin, Wen
> <wen.jin@xxxxxxxxx>; linux-pci@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx
> Subject: [PATCH v3 1/1] PCI/RCEC: Fix RCiEP capable devices RCEC association
> 
> 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.
> 
> 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>
> ---
> v2->v3:
>  Drop "[ Krzysztof: Update commit message. ]" from the commit message
> 
>  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