On Thu, Feb 26, 2015 at 10:37:50AM -0600, Bin Liu wrote: > Felipe, > > On Thu, Feb 26, 2015 at 10:31 AM, Felipe Balbi <balbi@xxxxxx> wrote: > > On Thu, Feb 26, 2015 at 10:21:38AM -0600, Bin Liu wrote: > >> Felipe, > >> > >> On Thu, Feb 26, 2015 at 9:07 AM, Felipe Balbi <balbi@xxxxxx> wrote: > >> > There was already a proper place where we were > >> > checking for babble interrupts, move babble > >> > recovery there. > >> > > >> > Signed-off-by: Felipe Balbi <balbi@xxxxxx> > >> > --- > >> > drivers/usb/musb/musb_core.c | 13 ++++++------- > >> > 1 file changed, 6 insertions(+), 7 deletions(-) > >> > > >> > diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c > >> > index 2767ce1bf016..0569b24719e6 100644 > >> > --- a/drivers/usb/musb/musb_core.c > >> > +++ b/drivers/usb/musb/musb_core.c > >> > @@ -892,6 +892,12 @@ b_host: > >> > } else { > >> > ERR("Stopping host session -- babble\n"); > >> > musb_writeb(musb->mregs, MUSB_DEVCTL, 0); > >> > + > >> > + if (is_host_active(musb)) { > >> > + musb_generic_disable(musb); > >> > + schedule_delayed_work(&musb->recover_work, > >> > + msecs_to_jiffies(100)); > >> > + } > >> > >> This change breaks babble recovery, because the following lines above here > >> > >> 873 if (devctl & (MUSB_DEVCTL_FSDEV | > >> MUSB_DEVCTL_LSDEV)) { > >> 874 dev_dbg(musb->controller, "BABBLE > >> devctl: %02x\n", devctl); > >> > >> have a bug - DEVCTL_FSDEV bit will be set for high-speed too, so this > >> 'if' traps babble handling for all cases, never hit on 'else'. > > > > We might as well drop that check altogether. Let me see what happens > > here. > > It is good to clean it up, but I guess the babble storm you see is > caused by something else. I debugged the storm last year in an older > kernel, it was due to the babble recovery routine does not maintain a > bit in MUSB_BABBLE_CTL, though I forgot the details now. I am looking > at this part in the upstream kernel right now. alright, I'll have a look, let's see. -- balbi
Attachment:
signature.asc
Description: Digital signature