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Commit f103b5d6 authored by Mauro Carvalho Chehab's avatar Mauro Carvalho Chehab
Browse files

[media] videobuf2: Fix CodingStyle 



Changeset b18a8ff2 added a comment violating the 80cols max size,
with no good reason.

Fix it.

Cc: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: default avatarMauro Carvalho Chehab <m.chehab@samsung.com>
parent b18a8ff2

drivers/media/v4l2-core/videobuf2-core.c

+10 −9
Original line number Diff line number Diff line
@@ -1246,15 +1246,16 @@ static int __buf_prepare(struct vb2_buffer *vb, const struct v4l2_buffer *b) 
		break;

	case V4L2_MEMORY_USERPTR:

		/*

		 * In case of user pointer buffers vb2 allocators need to get direct

		 * access to userspace pages. This requires getting the mmap semaphore

		 * for read access in the current process structure. The same semaphore

		 * is taken before calling mmap operation, while both qbuf/prepare_buf

		 * and mmap are called by the driver or v4l2 core with the driver's lock

		 * held. To avoid an AB-BA deadlock (mmap_sem then driver's lock in mmap

		 * and driver's lock then mmap_sem in qbuf/prepare_buf) the videobuf2

		 * core releases the driver's lock, takes mmap_sem and then takes the

		 * driver's lock again.

		 * In case of user pointer buffers vb2 allocators need to get

		 * direct access to userspace pages. This requires getting

		 * the mmap semaphore for read access in the current process

		 * structure. The same semaphore is taken before calling mmap

		 * operation, while both qbuf/prepare_buf and mmap are called

		 * by the driver or v4l2 core with the driver's lock held.

		 * To avoid an AB-BA deadlock (mmap_sem then driver's lock in

		 * mmap and driver's lock then mmap_sem in qbuf/prepare_buf),

		 * the videobuf2 core releases the driver's lock, takes

		 * mmap_sem and then takes the driver's lock again.

		 */

		mmap_sem = &current->mm->mmap_sem;

		call_qop(q, wait_prepare, q);