On Wed, Jun 26, 2013 at 09:53:34AM -0700, Sarah Sharp wrote: > 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. > > It's a known issue. The xHCI 1.0 spec changed how hardware handles > short packets. The HW will notify SW of the TRB where the short packet, > and it will also give a successful status for the last TRB in a TD (the > one with the IOC flag set). On the second successful status, that > warning will be triggered in the driver. > > Software is now supposed to not assume the TD as done until it gets that > last successful status. That means we have a slight race condition, > although it should have little practical impact. This patch papers over > that issue. > > I will take this patch, but will add the note that is on my long-term > to-do list to fix this issue. Actually, since it applies to both xhci-plat and xhci-pci hosts, can you move setting this quirk into xhci_gen_setup? Sarah Sharp > > Signed-off-by: George Cherian <george.cherian@xxxxxx> > > --- > > 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; > > } > > > > /* called during probe() after chip reset completes */ > > -- > > 1.8.1.4 > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-usb" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
