Re: [PATCH] PCI: pciehp: Add Qualcomm bridge (0x0110) to the command completed quirk

[Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>]

On Thu, Feb 10, 2022 at 04:49:30PM -0600, Bjorn Helgaas wrote:
> On Thu, Feb 10, 2022 at 08:20:03PM +0530, Manivannan Sadhasivam wrote:
> > The Qualcomm PCI bridge device (0x0110) found in chipsets such as SM8450
> > does not set the command completed bit unless writes to the Slot Command
> > register change "Control" bits.
> > 
> > This results in timeouts like below:
> > 
> > pcieport 0001:00:00.0: pciehp: Timeout on hotplug command 0x03c0 (issued 2020 msec ago)
> > 
> > Hence, add the device to the command completed quirk to mark commands
> > "completed" immediately unless they change the "Control" bits.
> > 
> > Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> 
> Applied to pci/hotplug for v5.18, thanks!
>

Thanks!

> Should we assume that this erratum will be fixed in future Qualcomm
> devices?  Or should we apply the quirk for all Qualcomm hotplug
> bridges, as we do for Intel?
> 

I'll check with the Qualcomm hardware folks and update here.

Regards,
Mani

> > ---
> >  drivers/pci/hotplug/pciehp_hpc.c | 2 ++
> >  1 file changed, 2 insertions(+)
> > 
> > diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c
> > index 1c1ebf3dad43..4e4ccf3afbe3 100644
> > --- a/drivers/pci/hotplug/pciehp_hpc.c
> > +++ b/drivers/pci/hotplug/pciehp_hpc.c
> > @@ -1084,6 +1084,8 @@ static void quirk_cmd_compl(struct pci_dev *pdev)
> >  }
> >  DECLARE_PCI_FIXUP_CLASS_EARLY(PCI_VENDOR_ID_INTEL, PCI_ANY_ID,
> >  			      PCI_CLASS_BRIDGE_PCI, 8, quirk_cmd_compl);
> > +DECLARE_PCI_FIXUP_CLASS_EARLY(PCI_VENDOR_ID_QCOM, 0x0110,
> > +			      PCI_CLASS_BRIDGE_PCI, 8, quirk_cmd_compl);
> >  DECLARE_PCI_FIXUP_CLASS_EARLY(PCI_VENDOR_ID_QCOM, 0x0400,
> >  			      PCI_CLASS_BRIDGE_PCI, 8, quirk_cmd_compl);
> >  DECLARE_PCI_FIXUP_CLASS_EARLY(PCI_VENDOR_ID_QCOM, 0x0401,
> > -- 
> > 2.25.1
> >