On Wed, Feb 26, 2014 at 02:19:38AM +0300, Sergei Shtylyov wrote:
> Hello.
>
> On 02/26/2014 12:36 AM, Felipe Balbi wrote:
>
> >Revisions between 2.10a and 2.50a (included) have
> >a known issue which may cause xHCI compliance tests
> >to fail and/or quality issues with Isochronous
> >transactions.
>
> >Note that this issue only impacts certain configurations
> >of those revisions, namely the ones which have clock
> >gating enabled.
>
> >The suggested workaround is to disable clock gating in
> >known broken revisions, make sure HW LPM is disabled
> >and set GCTL.SOFITPSYNC to 1.
>
> >Signed-off-by: Felipe Balbi <balbi@xxxxxx>
> >---
> > drivers/usb/dwc3/core.c | 37 ++++++++++++++++++++++++++++---------
> > 1 file changed, 28 insertions(+), 9 deletions(-)
>
> >diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
> >index 1cf1fb5..3270974 100644
> >--- a/drivers/usb/dwc3/core.c
> >+++ b/drivers/usb/dwc3/core.c
> >@@ -389,7 +389,26 @@ static int dwc3_core_init(struct dwc3 *dwc)
> >
> > switch (DWC3_GHWPARAMS1_EN_PWROPT(dwc->hwparams.hwparams1)) {
> > case DWC3_GHWPARAMS1_EN_PWROPT_CLK:
> >- reg &= ~DWC3_GCTL_DSBLCLKGTNG;
> >+ /**
> >+ * WORKAROUND: DWC3 revisions between 2.10a and 2.50a have an
> >+ * issue which would cause xHCI compliance tests to fail.
> >+ *
> >+ * Because of that we cannot enable clock gating on such
> >+ * configurations.
> >+ *
> >+ * Refers to:
> >+ *
> >+ * STAR#9000588375: Clock Gating, SOF Issues when ref_clk-Based
> >+ * SOF/ITP Mode Used
> >+ */
> >+ if ((dwc->dr_mode == USB_DR_MODE_HOST ||
> >+ dwc->dr_mode == USB_DR_MODE_OTG) &&
> >+ (dwc->revision >= DWC3_REVISION_210A &&
> >+ dwc->revision <= DWC3_REVISION_250A)) {
> >+ reg |= DWC3_GCTL_DSBLCLKGTNG | DWC3_GCTL_SOFITPSYNC;
> >+ } else {
> >+ reg &= ~DWC3_GCTL_DSBLCLKGTNG;
> >+ }
>
> I'm surprised checkpatch.pl doesn't protest about {} here. :-)
hehe, it was supposed to have more lines and then I figured it wouldn't
be needed. I'll remove those braces. Thanks for noticing.
--
balbi
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