Hi, John Stultz <john.stultz@xxxxxxxxxx> writes: > From: Yu Chen <chenyu56@xxxxxxxxxx> > > Just resending this, as discussion died out a bit and I'm not > sure how to make further progress. See here for debug data that > was requested last time around: > https://lore.kernel.org/lkml/CALAqxLXdnaUfJKx0aN9xWwtfWVjMWigPpy2aqsNj56yvnbU80g@xxxxxxxxxxxxxx/ > > With the current dwc3 code on the HiKey960 we often see the > COREIDLE flag get stuck off in __dwc3_gadget_start(), which > seems to prevent the reset irq and causes the USB gadget to > fail to initialize. > > We had seen occasional initialization failures with older > kernels but with recent 5.x era kernels it seemed to be becoming > much more common, so I dug back through some older trees and > realized I dropped this quirk from Yu Chen during upstreaming > as I couldn't provide a proper rational for it and it didn't > seem to be necessary. I now realize I was wrong. > > After resubmitting the quirk, Thinh Nguyen pointed out that it > shouldn't be a quirk at all and it is actually mentioned in the > programming guide that it should be done when switching modes > in DRD. > > So, to avoid these !COREIDLE lockups seen on HiKey960, this > patch issues GCTL soft reset when switching modes if the > controller is in DRD mode. > > Cc: Felipe Balbi <balbi@xxxxxxxxxx> > Cc: Tejas Joglekar <tejas.joglekar@xxxxxxxxxxxx> > Cc: Yang Fei <fei.yang@xxxxxxxxx> > Cc: YongQin Liu <yongqin.liu@xxxxxxxxxx> > Cc: Andrzej Pietrasiewicz <andrzej.p@xxxxxxxxxxxxx> > Cc: Thinh Nguyen <thinhn@xxxxxxxxxxxx> > Cc: Jun Li <lijun.kernel@xxxxxxxxx> > Cc: Mauro Carvalho Chehab <mchehab+huawei@xxxxxxxxxx> > Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> > Cc: linux-usb@xxxxxxxxxxxxxxx > Signed-off-by: Yu Chen <chenyu56@xxxxxxxxxx> > Signed-off-by: John Stultz <john.stultz@xxxxxxxxxx> > --- > v2: > * Rework to always call the GCTL soft reset in DRD mode, > rather then using a quirk as suggested by Thinh Nguyen > > v3: > * Move GCTL soft reset under the spinlock as suggested by > Thinh Nguyen Because this is such an invasive change, I would prefer that we get Tested-By tags from a good fraction of the users before applying these two changes. -- balbi
