Re: [PATCH v2] PCI/portdrv: Use link bandwidth notification capability bit

[Lukas Wunner <lukas@wunner.de>]

On Fri, May 14, 2021 at 03:03:03PM +0200, Krzysztof Wilczy??ski wrote:
> > The pcieport driver can fail to attach to a downstream port that doesn't
> > support bandwidth notification.  This can happen when, in
> > pcie_port_device_register(), pci_init_service_irqs() tries (and fails) to
> > set up a bandwidth notification IRQ for a device that doesn't support it.
> > 
> > This patch changes get_port_device_capability() to look at the link
> > bandwidth notification capability bit in the link capabilities register of
> > the port, instead of assuming that all downstream ports have that
> > capability.
> 
> I was wondering - is this fix connected to an issue filled in Bugzilla
> or does it fix a known commit that introduced this problem?  Basically,
> I am trying to see whether a "Fixes:" would be in order.

The fix is for a driver which has been removed from the tree (for now),
including in stable kernels.  The fix will prevent an issue that will
occur once the driver is re-introduced (once we've found a way to
overcome the issues that led to its removal).  A Fixes tag is thus
uncalled for.

Thanks,

Lukas