[Quantal][SRU][PATCH 2/2] usb: xhci: add USB2 Link power management BESL support

Shawn Wang shawn.wang at canonical.com
Mon Sep 30 09:14:40 UTC 2013


Hi Tim,
 I did some regression tests and posted it on
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1229576.

Webcam test:
 preview with resolution change (cheese/guvcview)
 Take photos.
 S3 stress 30 times than preview and take photos.

Other usb device test:
 USB mouse (8564:1000)
 usb disk (0781:5571 SanDisk Corp.)
 usb bt (8087:07dc)

Regards,
Shawn



On Thu, Sep 26, 2013 at 11:07 PM, Tim Gardner <tim.gardner at canonical.com>wrote:

> On 09/26/2013 02:32 AM, Shawn Wang wrote:
> > Hi Tim,
> >  The original commit a558ccdcc71c7770c5e80c926a31cfe8a3892a09
> > add usb2_hw_lpm_besl_capable in struct
> >  usb3_lpm_parameters. (include/linux/usb.h)
> >  However, the XHCI_HLC and XHCI_BLC are the same.
> >  We skip the below change, use usb2_hw_lpm_capable to instead of
> > usb2_hw_lpm_besl_capable.
> >  If add dcf06a036848b4e8e6c8220f2e00b9adf6f84918, should we change the
> > struct usb3_lpm_parameters?
> >
> >  Some realtek webcam modules need the backport to fix preview issues.
> >
> > a558ccdcc71c7770c5e80c926a31cfe8a3892a09
> >
> >  +++ b/drivers/usb/host/xhci-ext-caps.h
> >   @@ -71,6 +71,7 @@
> >
> >    /* USB 2.0 xHCI 1.0 hardware LMP capability - section 7.2.2.1.3.2 */
> >    #define XHCI_HLC               (1 << 19)
> >   +#define XHCI_BLC               (1 << 19)
> >
> >   @@ -4068,6 +4191,9 @@ int xhci_update_device(struct usb_hcd *hcd,
> > struct usb_device *udev)
> >           if (xhci->hw_lpm_support == 1 &&
> >               xhci_check_usb2_port_capability(xhci, portnum, XHCI_HLC)) {
> >               udev->usb2_hw_lpm_capable = 1;
> >   +           if (xhci_check_usb2_port_capability(xhci, portnum,
> >   +                               XHCI_BLC))
> >   +               udev->usb2_hw_lpm_besl_capable = 1;
> >
> >
> > dcf06a036848b4e8e6c8220f2e00b9adf6f84918
> >
> >  /* USB 2.0 xHCI 1.0 hardware LMP capability - section 7.2.2.1.3.2 */
> >  #define XHCI_HLC               (1 << 19)
> > -#define XHCI_BLC               (1 << 19)
> > +#define XHCI_BLC               (1 << 20)
> >
> > Regards,
> > Shawn
> >
>
> Ah, never mind. The back port of
> a558ccdcc71c7770c5e80c926a31cfe8a3892a09 looks OK. However, there is no
> mention in the bug report of any kind of regression tests having been
> performed. This looks like a code path that will affect a lot of devices.
>
> rtg
> --
> Tim Gardner tim.gardner at canonical.com
>
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