On Tue, Dec 15, 2015 at 09:22:56AM -0800, Dmitry Torokhov wrote: > On Tue, Dec 15, 2015 at 5:30 AM, Gustavo Padovan <gustavo@xxxxxxxxxxx> wrote: > > 2015-12-14 Dmitry Torokhov <dtor@xxxxxxxxxxxx>: > > > >> Userspace can close the sync device while there are still active fence > >> points, in which case kernel produces the following warning: > >> > >> [ 43.853176] ------------[ cut here ]------------ > >> [ 43.857834] WARNING: CPU: 0 PID: 892 at /mnt/host/source/src/third_party/kernel/v3.18/drivers/staging/android/sync.c:439 android_fence_release+0x88/0x104() > >> [ 43.871741] CPU: 0 PID: 892 Comm: Binder_5 Tainted: G U 3.18.0-07661-g0550ce9 #1 > >> [ 43.880176] Hardware name: Google Tegra210 Smaug Rev 1+ (DT) > >> [ 43.885834] Call trace: > >> [ 43.888294] [<ffffffc000207464>] dump_backtrace+0x0/0x10c > >> [ 43.893697] [<ffffffc000207580>] show_stack+0x10/0x1c > >> [ 43.898756] [<ffffffc000ab1258>] dump_stack+0x74/0xb8 > >> [ 43.903814] [<ffffffc00021d414>] warn_slowpath_common+0x84/0xb0 > >> [ 43.909736] [<ffffffc00021d530>] warn_slowpath_null+0x14/0x20 > >> [ 43.915482] [<ffffffc00088aefc>] android_fence_release+0x84/0x104 > >> [ 43.921582] [<ffffffc000671cc4>] fence_release+0x104/0x134 > >> [ 43.927066] [<ffffffc00088b0cc>] sync_fence_free+0x74/0x9c > >> [ 43.932552] [<ffffffc00088b128>] sync_fence_release+0x34/0x48 > >> [ 43.938304] [<ffffffc000317bbc>] __fput+0x100/0x1b8 > >> [ 43.943185] [<ffffffc000317cc8>] ____fput+0x8/0x14 > >> [ 43.947982] [<ffffffc000237f38>] task_work_run+0xb0/0xe4 > >> [ 43.953297] [<ffffffc000207074>] do_notify_resume+0x44/0x5c > >> [ 43.958867] ---[ end trace 5a2aa4027cc5d171 ]--- > > > > This crash report seems to be for a 3.18 kernel. Can you reproduce it > > on upstream kernel as well? > > Unfortunately this board does not run upsrteam just yet, but looking > at the sync driver and fence code we are pretty much in sync with > upstream. Just to check: Is that with a proper hw driver, or using SW_SYNC? The later will get removed in upstream since it's a debug/validation only interface. Well, removed for drivers and production systems, the kselftests will use it. -Daniel -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
