Messages in this thread | | | Date | Wed, 26 Jun 2013 17:46:29 +0530 | From | George Cherian <> | Subject | Re: [PATCH] usb: host: xhci-plat: Enable XHCI_SPURIOUS_SUCCESS quirk for xhci-plat |
| |
On 6/26/2013 2:32 PM, Felipe Balbi wrote: > Hi, > > On Wed, Jun 26, 2013 at 02:28:57PM +0530, George Cherian wrote: >> Synopsis xhci controllers with hci_version > 0.96 gives spurious success >> events on short packet completion. During webcam capture the >> "ERROR Transfer event TRB DMA ptr not part of current TD" was observed. >> The same application works fine with synopsis controllers hci_version 0.96. >> >> Signed-off-by: George Cherian<george.cherian@ti.com> >> --- >> drivers/usb/host/xhci-plat.c | 10 ++++++++++ >> 1 file changed, 10 insertions(+) >> >> diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c >> index 93ad67e..e63c6d3 100644 >> --- a/drivers/usb/host/xhci-plat.c >> +++ b/drivers/usb/host/xhci-plat.c >> @@ -25,6 +25,16 @@ static void xhci_plat_quirks(struct device *dev, struct xhci_hcd *xhci) >> * dev struct in order to setup MSI >> */ >> xhci->quirks |= XHCI_BROKEN_MSI; >> + >> + /* >> + * In some xhci controllers which follows xhci 1.0 spec gives a spurious >> + * success event after a short transfer. This quirk will ignore such >> + * spurious event. Hit this issue in synopsis xhci controllers with >> + * hci_version > 0.96 >> + */ >> + >> + if (xhci->hci_version > 0x96) >> + xhci->quirks |= XHCI_SPURIOUS_SUCCESS; >> } > doesn't look like the correct way to do this. What if enabling that > quirk on hosts which don't have the quirk cause problems ? For a controller which does not have this issue will never get a spurious success for short packet ( and that too for only ISOCH).
per this commit ad808333d Intel xhci: Ignore spurious successful event.
This spurious successful event behavior isn't technically disallowed by the xHCI specification, so make the xHCI driver just ignore the spurious completion event. > I would suggest adding a platform_data which (in our case) dwc3 will > pass to xhci-plat. Then you can do proper revision detection of the > synopsys controller and set the quirk only on the failing hosts. > > BTW, do you have the STARS number for this errata ? No STARS number yet.
Regards -George
| |