From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ritesh Raj Sarraf Subject: Re: xHCI problem? [was Re: Erratic USB device behavior and device loss] Date: Fri, 16 Sep 2016 21:12:05 +0530 Message-ID: <1474040525.18741.1.camel@researchut.com> References: Reply-To: rrs@researchut.com Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit Return-path: Received: from mail-pf0-f195.google.com ([209.85.192.195]:34123 "EHLO mail-pf0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935603AbcIPPmV (ORCPT ); Fri, 16 Sep 2016 11:42:21 -0400 Received: by mail-pf0-f195.google.com with SMTP id 21so2336413pfy.1 for ; Fri, 16 Sep 2016 08:42:21 -0700 (PDT) In-Reply-To: Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: Alan Stern , Ulf Hansson Cc: USB list , linux-mmc -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 Hello Ulf and Alan, On Thu, 2016-09-15 at 10:16 -0400, Alan Stern wrote: > > --- > >  drivers/mmc/host/rtsx_usb_sdmmc.c | 2 ++ > >  1 file changed, 2 insertions(+) > >  > > diff --git a/drivers/mmc/host/rtsx_usb_sdmmc.c > > b/drivers/mmc/host/rtsx_usb_sdmmc.c > > index 6c71fc9..a59c7fa 100644 > > --- a/drivers/mmc/host/rtsx_usb_sdmmc.c > > +++ b/drivers/mmc/host/rtsx_usb_sdmmc.c > > @@ -1314,6 +1314,7 @@ static void rtsx_usb_update_led(struct work_struct > *work) > >                 container_of(work, struct rtsx_usb_sdmmc, led_work); > >         struct rtsx_ucr *ucr = host->ucr; > >  > > +       pm_runtime_get_sync(sdmmc_dev(host)); > >         mutex_lock(&ucr->dev_mutex); > >  > >         if (host->led.brightness == LED_OFF) > > @@ -1322,6 +1323,7 @@ static void rtsx_usb_update_led(struct work_struct > *work) > >                 rtsx_usb_turn_on_led(ucr); > >  > >         mutex_unlock(&ucr->dev_mutex); > > +       pm_runtime_put(sdmmc_dev(host)); > >  } > >  #endif > >  > > --  > >  > > Although, I doubt the above is the main reason to the issues we see. > > I don't know -- it could well be the reason.  The symptoms are  > definitely what you would expect to see if some thread was doing I/O  > without calling the pm_runtime_* routines. > > > Instead I think somehow the parent device (usb device) isn't being > > properly managed through runtime PM, but not due to wrong deployment > > in the mmc core nor in the rtsx_usb_driver, but at some place else. > > :-) > >  > > I started looking for calls to pm_suspend_ignore_children(dev, true), > > which would decouple the usb device from the mmc platform device from > > a runtime PM point of view. I found one suspicious case! > >  > > drivers/usb/storage/realtek_cr.c: > > pm_suspend_ignore_children(&us->pusb_intf->dev, true); > >  > > As I am not so familiar with USB, I can't really tell why the above > > exists, although perhaps just removing that line would be worth a > > try!? > > No, the realtek_cr driver has no connection with this.  It's a > sub-module of the usb_storage driver; it uses the SCSI interface, > not the MMC interface. > > > If neither of the above works, the next step could be to start > > checking error codes in the mmc core and in the rtsx_usb_sdmmc driver, > > from the calls to pm_runtime_get|put() and pm_runtime_enable(). > > Let's see what this patch does. I was able to hit it again. Please find the usbmon trace at: https://people.debian.org/~rrs/tmp/usb-4.8.0-rc6ulf1+.log.gz - -- Ritesh Raj Sarraf RESEARCHUT - http://www.researchut.com "Necessity is the mother of invention." -----BEGIN PGP SIGNATURE----- iQIcBAEBCgAGBQJX3BLOAAoJEKY6WKPy4XVpXMgP/jTyKOX/SYCPTU9twYldY7LQ f64hpiWqXOUs+jFYM+BcrF5B5DuXiB1Wm4F3+Xm/QBN3grJD7yBq1nrhv/mAhCr3 y1gFRIbeKfZsEp1vdBov9m1jQCZzzIZlFXPmRGT/8uC/GZTHlgIeSLqBntpq9+yL MQSE91tLVayVgaOQxpPz+uZ4PTAom19sU21Haa90ECHLKAUTJ9WncQFecjPLHMjb 4SUvgq53V2s1Yo1E85RhtgR6Nrk/Bh7qZEC1NyeganLazGbbsz9YnRcGy58x9Jiq xmfURTtvG834CnGcGuzcRU09FGPMtXx/u57EYC6mdEMWhSglo0h6YhVxcUOtAhRD s1gs+a6ToKTDLn6qr0cnIwG27ALyLh41QmzxEpiaZiugIEBzZ/uK3TBjzcul4Huj v0+x2fSC0SXwGo4P3GAOnHuWUjgj3C1wElP1R3brXfO0aayESUNKzE8V7RbQIWiC mHewSlKTiPwCr/lchaINTt2TyFcHJWOx90iV10GO5TpMyqho4AzpBpoimItrbx2t qQJCvGzDLPjr0tPvpeWyJSfBnqCDqbJ44CY3nCFgKhTd3BXp4fDj09eBtNmSiuvu UdZZxm84FD3BDSNX8k2W9CF81jML/4lzwliJge3uIPrXNDqGSZMxDSpd0u1EFNHf rEQ/kP1WlArvqButQ5ZN =fiWV -----END PGP SIGNATURE-----