Re[2]: [PATCH] fix: add XHCI_SPURIOUS_SUCCESS to ASM1042 despite being a V0.96 controller

[Jens Glathe]

Hi there,

thank you for the hint, I'll amend the commit text. For practical 
purposes you won't need to check for ASM1042/0x96, however according to 
documentation it *should* be a V1.0 XHCI controller. So, the defensive 
approach would be to check for it (so its a quirk only in this case), 
the outcome without checking would be the same. I can take it out, 
adding the quirk for ASM1042 would be sufficient.

with best regards

Jens

------ Originalnachricht ------
Von "Mathias Nyman" <mathias.nyman@xxxxxxxxxxxxxxx>
An "Jens Glathe" <jens.glathe@xxxxxxxxxxxxxxxxxxxxxx>; 
mathias.nyman@xxxxxxxxx
Cc gregkh@xxxxxxxxxxxxxxxxxxx; linux-usb@xxxxxxxxxxxxxxx; 
linux-kernel@xxxxxxxxxxxxxxx
Datum 26.09.2022 13:31:42
Betreff Re: [PATCH] fix: add XHCI_SPURIOUS_SUCCESS to ASM1042 despite 
being a V0.96 controller

> Hi
>
> Thanks for the patch, some small changes still needed:
>
> Include subsystem in subject line, something like
> usb: xhci: Add XHCI_SPURIOUS...
>
> On 25.9.2022 20.22, Jens Glathe wrote:
> > only if it reports as a V0.96 XHCI controller. Appears to fix the errors
> > "xhci_hcd <address>; ERROR Transfer event TRB DMA ptr not part of
> > current TD ep_index 2 comp_code 13" that appear spuriously (or pretty
> > often) when using a r8152 USB3 ethernet adapter with integrated hub.
> >
> > Signed-off-by: Jens Glathe <jens.glathe@xxxxxxxxxxxxxxxxxxxxxx>
> > ---
> >   drivers/usb/host/xhci-pci.c | 6 +++++-
> >   1 file changed, 5 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c
> > index dce6c0ec8d34..d1b8e7148dd1 100644
> > --- a/drivers/usb/host/xhci-pci.c
> > +++ b/drivers/usb/host/xhci-pci.c
> > @@ -306,8 +306,12 @@ static void xhci_pci_quirks(struct device *dev, struct xhci_hcd *xhci)
> >   	}
> >     	if (pdev->vendor == PCI_VENDOR_ID_ASMEDIA &&
> > -		pdev->device == PCI_DEVICE_ID_ASMEDIA_1042_XHCI)
> > +		pdev->device == PCI_DEVICE_ID_ASMEDIA_1042_XHCI) {
> > +		/* try to tame the ASMedia 1042 controller which is 0.96 */
> > +		if (xhci->hci_version == 0x96)
>
> Do we need this 0x96 check? It's anyway set for 1.0 and newer controllers
>
> > +			xhci->quirks |= XHCI_SPURIOUS_SUCCESS;
>
> This reminds me that I should get rid of this quirk.
>
> If we get a short transfers event for a TRB mid TD, then xhci hosts version 1.0 and later
> should send a second event for the last TRB in the TD
>
> so this is default behavior for modern xHCI, not a spurious event.
>
> But your patch is anyways needed for stable kernels.
>
> Thanks
> -Mathias