forked from Minki/linux
e2c91d4d78
Right now, the lock schema for media_device struct is messy, since sometimes, it is protected via a spin lock, while, for media graph traversal, it is protected by a mutex. Solve this conflict by always using a mutex. As a side effect, this prevents a bug when the media notifiers is called at atomic context, while running the notifier callback: BUG: sleeping function called from invalid context at mm/slub.c:1289 in_atomic(): 1, irqs_disabled(): 0, pid: 3479, name: modprobe 4 locks held by modprobe/3479: #0: (&dev->mutex){......}, at: [<ffffffff81ce8933>] __driver_attach+0xa3/0x160 #1: (&dev->mutex){......}, at: [<ffffffff81ce8941>] __driver_attach+0xb1/0x160 #2: (register_mutex#5){+.+.+.}, at: [<ffffffffa10596c7>] usb_audio_probe+0x257/0x1c90 [snd_usb_audio] #3: (&(&mdev->lock)->rlock){+.+.+.}, at: [<ffffffffa0e6051b>] media_device_register_entity+0x1cb/0x700 [media] CPU: 2 PID: 3479 Comm: modprobe Not tainted 4.5.0-rc3+ #49 Hardware name: /NUC5i7RYB, BIOS RYBDWi35.86A.0350.2015.0812.1722 08/12/2015 0000000000000000 ffff8803b3f6f288 ffffffff81933901 ffff8803c4bae000 ffff8803c4bae5c8 ffff8803b3f6f2b0 ffffffff811c6af5 ffff8803c4bae000 ffffffff8285d7f6 0000000000000509 ffff8803b3f6f2f0 ffffffff811c6ce5 Call Trace: [<ffffffff81933901>] dump_stack+0x85/0xc4 [<ffffffff811c6af5>] ___might_sleep+0x245/0x3a0 [<ffffffff811c6ce5>] __might_sleep+0x95/0x1a0 [<ffffffff8155aade>] kmem_cache_alloc_trace+0x20e/0x300 [<ffffffffa0e66e3d>] ? media_add_link+0x4d/0x140 [media] [<ffffffffa0e66e3d>] media_add_link+0x4d/0x140 [media] [<ffffffffa0e69931>] media_create_pad_link+0xa1/0x600 [media] [<ffffffffa0fe11b3>] au0828_media_graph_notify+0x173/0x360 [au0828] [<ffffffffa0e68a6a>] ? media_gobj_create+0x1ba/0x480 [media] [<ffffffffa0e606fb>] media_device_register_entity+0x3ab/0x700 [media] Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com> Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com> Acked-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com> |
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| .. | ||
| blackfin | ||
| davinci | ||
| drv-intf | ||
| i2c | ||
| i2c-addr.h | ||
| lirc_dev.h | ||
| lirc.h | ||
| media-device.h | ||
| media-devnode.h | ||
| media-entity.h | ||
| rc-core.h | ||
| rc-map.h | ||
| soc_camera.h | ||
| tuner-types.h | ||
| tuner.h | ||
| tveeprom.h | ||
| v4l2-async.h | ||
| v4l2-clk.h | ||
| v4l2-common.h | ||
| v4l2-ctrls.h | ||
| v4l2-dev.h | ||
| v4l2-device.h | ||
| v4l2-dv-timings.h | ||
| v4l2-event.h | ||
| v4l2-fh.h | ||
| v4l2-flash-led-class.h | ||
| v4l2-image-sizes.h | ||
| v4l2-ioctl.h | ||
| v4l2-mc.h | ||
| v4l2-mediabus.h | ||
| v4l2-mem2mem.h | ||
| v4l2-of.h | ||
| v4l2-subdev.h | ||
| videobuf2-core.h | ||
| videobuf2-dma-contig.h | ||
| videobuf2-dma-sg.h | ||
| videobuf2-dvb.h | ||
| videobuf2-memops.h | ||
| videobuf2-v4l2.h | ||
| videobuf2-vmalloc.h | ||
| videobuf-core.h | ||
| videobuf-dma-contig.h | ||
| videobuf-dma-sg.h | ||
| videobuf-dvb.h | ||
| videobuf-vmalloc.h | ||
| vsp1.h | ||