Re: [PATCH] usb: xhci-plat: Enable USB 2.0 hardware LPM support forplatform xHCs

From: Julius Werner
Date: Wed Aug 21 2013 - 17:44:01 EST


> Thanks for the patch! Did you test with a USB analyzer to see if the
> device was actually going into USB 2.0 Link PM? I'd like to confirm we
> really aren't breaking anything for DW3 hosts by enabling this.

Yes, I did. The LPM transfers on the analyzer look good and the device
works as expected.

My platform only runs a 3.8 derivative, though, so I now have also
cherry-picked the BESL patches that went in since then to make sure
they don't break things. I had problems on one device until I found
the XHCI_BLC fix Mathias sent out this morning, so you should pick
that one up first. (Without it LPM doesn't break completely but seems
to assert resume for less time than the HIRD defines, so the device
sometimes gets confused and resets. I can't figure out how BESL is
really supposed to work since the XHCI spec from 8/14/12 where it's
supposedly defined doesn't seem to be publicly available.)
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