On Fri, Feb 13, 2015 at 8:12 AM, Takashi Iwai <tiwai@xxxxxxx> wrote: > At Fri, 13 Feb 2015 12:41:25 -0200, > Mauro Carvalho Chehab wrote: >> >> Em Fri, 13 Feb 2015 15:02:42 +0100 >> Takashi Iwai <tiwai@xxxxxxx> escreveu: >> >> > At Mon, 09 Feb 2015 11:59:07 +0100, >> > Takashi Iwai wrote: >> > > >> > > Hi, >> > > >> > > we've got a bug report about the suspend/resume regression of DVB >> > > device with 3.19. The symptom is VLC doesn't work after S3 or S4 >> > > resume. strace shows that /dev/dvb/adaptor0/dvr returns -ENODEV. >> > > >> > > The reporter confirmed that 3.18 works fine, so the regression must be >> > > in 3.19. >> > > >> > > There is a relevant kernel warning while suspending: >> > > >> > > WARNING: CPU: 1 PID: 3603 at ../kernel/module.c:1001 module_put+0xc7/0xd0() >> > > Workqueue: events_unbound async_run_entry_fn >> > > 0000000000000000 ffffffff81a45779 ffffffff81664f12 0000000000000000 >> > > ffffffff81062381 0000000000000000 ffffffffa051eea0 ffff8800ca369278 >> > > ffffffffa051a068 ffff8800c0a18090 ffffffff810dfb47 0000000000000000 >> > > Call Trace: >> > > [<ffffffff810055ac>] dump_trace+0x8c/0x340 >> > > [<ffffffff81005903>] show_stack_log_lvl+0xa3/0x190 >> > > [<ffffffff81007061>] show_stack+0x21/0x50 >> > > [<ffffffff81664f12>] dump_stack+0x47/0x67 >> > > [<ffffffff81062381>] warn_slowpath_common+0x81/0xb0 >> > > [<ffffffff810dfb47>] module_put+0xc7/0xd0 >> > > [<ffffffffa04d98d1>] dvb_usb_adapter_frontend_exit+0x41/0x60 [dvb_usb] >> > > [<ffffffffa04d8451>] dvb_usb_exit+0x31/0xa0 [dvb_usb] >> > > [<ffffffffa04d84fb>] dvb_usb_device_exit+0x3b/0x50 [dvb_usb] >> > > [<ffffffff814cefad>] usb_unbind_interface+0x1ed/0x2c0 >> > > [<ffffffff8145ceae>] __device_release_driver+0x7e/0x100 >> > > [<ffffffff8145cf52>] device_release_driver+0x22/0x30 >> > > [<ffffffff814cf13d>] usb_forced_unbind_intf+0x2d/0x60 >> > > [<ffffffff814cf3c3>] usb_suspend+0x73/0x130 >> > > [<ffffffff814bd453>] usb_dev_freeze+0x13/0x20 >> > > [<ffffffff81468fca>] dpm_run_callback+0x4a/0x150 >> > > [<ffffffff81469c81>] __device_suspend+0x121/0x350 >> > > [<ffffffff81469ece>] async_suspend+0x1e/0xa0 >> > > [<ffffffff81081e63>] async_run_entry_fn+0x43/0x150 >> > > [<ffffffff81079e72>] process_one_work+0x142/0x3f0 >> > > [<ffffffff8107a234>] worker_thread+0x114/0x460 >> > > [<ffffffff8107f3b1>] kthread+0xc1/0xe0 >> > > [<ffffffff8166b77c>] ret_from_fork+0x7c/0xb0 >> > > >> > > So something went wrong in module refcount, which likely leads to >> > > disabling the device and returning -ENODEV in the end. >> > > Hi Takashi and Mauro, Looking at the stack trace usb_forced_unbind_intf() gets called from usb_suspend(). Looks like the suspend path in unbind_no_pm_drivers_interfaces() determines the driver doesn't have suspend/resume support and goes to usb_forced_unbind_intf(). At this point forced unbinding results in release the driver via usb_driver_release_interface(). It is worth looking into if the driver indeed has suspend/resume routines? -- Shuah > -- > To unsubscribe from this list: send the line "unsubscribe linux-media" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
