[lvc-project] [PATCH rtw-next] wifi: rtw88: check for PCI upstream bridge existence

[Ping-Ke Shih]

Fedor Pchelkin <pchelkin at ispras.ru> wrote:
> pci_upstream_bridge() returns NULL if the device is on a root bus.  If
> 8821CE is installed in the system with such a PCI topology, the probing
> routine will crash.  This has probably been unnoticed as 8821CE is mostly
> supplied in laptops where there is a PCI-to-PCI bridge located upstream
> from the device.  However the card might be installed on a system with
> different configuration.
> 
> Check if the bridge does exist for the specific workaround to be applied.
> 
> Found by Linux Verification Center (linuxtesting.org) with Svace static
> analysis tool.
> 
> Fixes: 24f5e38a13b5 ("rtw88: Disable PCIe ASPM while doing NAPI poll on 8821CE")
> Cc: stable at vger.kernel.org
> Signed-off-by: Fedor Pchelkin <pchelkin at ispras.ru>

Acked-by: Ping-Ke Shih <pkshih at realtek.com>