diff options
Diffstat (limited to 'target/linux/bcm27xx/patches-4.19/950-0602-media-vb2-Allow-reqbufs-0-with-in-use-MMAP-buffers.patch')
| -rw-r--r-- | target/linux/bcm27xx/patches-4.19/950-0602-media-vb2-Allow-reqbufs-0-with-in-use-MMAP-buffers.patch | 130 |
1 files changed, 0 insertions, 130 deletions
diff --git a/target/linux/bcm27xx/patches-4.19/950-0602-media-vb2-Allow-reqbufs-0-with-in-use-MMAP-buffers.patch b/target/linux/bcm27xx/patches-4.19/950-0602-media-vb2-Allow-reqbufs-0-with-in-use-MMAP-buffers.patch deleted file mode 100644 index 755ca34440..0000000000 --- a/target/linux/bcm27xx/patches-4.19/950-0602-media-vb2-Allow-reqbufs-0-with-in-use-MMAP-buffers.patch +++ /dev/null @@ -1,130 +0,0 @@ -From 16cf378051d7fff6772a7acaecbacddec7822330 Mon Sep 17 00:00:00 2001 -From: John Sheu <sheu@chromium.org> -Date: Thu, 15 Nov 2018 10:57:16 -0500 -Subject: [PATCH] media: vb2: Allow reqbufs(0) with "in use" MMAP - buffers - -Upstream commit d644cca50f366cd109845ae92e37c09ed79adf81 - -Videobuf2 presently does not allow VIDIOC_REQBUFS to destroy outstanding -buffers if the queue is of type V4L2_MEMORY_MMAP, and if the buffers are -considered "in use". This is different behavior than for other memory -types and prevents us from deallocating buffers in following two cases: - -1) There are outstanding mmap()ed views on the buffer. However even if - we put the buffer in reqbufs(0), there will be remaining references, - due to vma .open/close() adjusting vb2 buffer refcount appropriately. - This means that the buffer will be in fact freed only when the last - mmap()ed view is unmapped. - -2) Buffer has been exported as a DMABUF. Refcount of the vb2 buffer - is managed properly by VB2 DMABUF ops, i.e. incremented on DMABUF - get and decremented on DMABUF release. This means that the buffer - will be alive until all importers release it. - -Considering both cases above, there does not seem to be any need to -prevent reqbufs(0) operation, because buffer lifetime is already -properly managed by both mmap() and DMABUF code paths. Let's remove it -and allow userspace freeing the queue (and potentially allocating a new -one) even though old buffers might be still in processing. - -To let userspace know that the kernel now supports orphaning buffers -that are still in use, add a new V4L2_BUF_CAP_SUPPORTS_ORPHANED_BUFS -to be set by reqbufs and create_bufs. - -[p.zabel@pengutronix.de: added V4L2_BUF_CAP_SUPPORTS_ORPHANED_BUFS, - updated documentation, and added back debug message] - -Signed-off-by: John Sheu <sheu@chromium.org> -Reviewed-by: Pawel Osciak <posciak@chromium.org> -Signed-off-by: Tomasz Figa <tfiga@chromium.org> -Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de> -Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com> -Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl> -[hverkuil-cisco@xs4all.nl: added V4L2-BUF-CAP-SUPPORTS-ORPHANED-BUFS ref] -Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> ---- - Documentation/media/uapi/v4l/vidioc-reqbufs.rst | 17 ++++++++++++++--- - drivers/media/common/videobuf2/videobuf2-core.c | 8 +++----- - drivers/media/common/videobuf2/videobuf2-v4l2.c | 2 +- - include/uapi/linux/videodev2.h | 1 + - 4 files changed, 19 insertions(+), 9 deletions(-) - ---- a/Documentation/media/uapi/v4l/vidioc-reqbufs.rst -+++ b/Documentation/media/uapi/v4l/vidioc-reqbufs.rst -@@ -59,9 +59,14 @@ When the I/O method is not supported the - code. - - Applications can call :ref:`VIDIOC_REQBUFS` again to change the number of --buffers, however this cannot succeed when any buffers are still mapped. --A ``count`` value of zero frees all buffers, after aborting or finishing --any DMA in progress, an implicit -+buffers. Note that if any buffers are still mapped or exported via DMABUF, -+then :ref:`VIDIOC_REQBUFS` can only succeed if the -+``V4L2_BUF_CAP_SUPPORTS_ORPHANED_BUFS`` capability is set. Otherwise -+:ref:`VIDIOC_REQBUFS` will return the ``EBUSY`` error code. -+If ``V4L2_BUF_CAP_SUPPORTS_ORPHANED_BUFS`` is set, then these buffers are -+orphaned and will be freed when they are unmapped or when the exported DMABUF -+fds are closed. A ``count`` value of zero frees or orphans all buffers, after -+aborting or finishing any DMA in progress, an implicit - :ref:`VIDIOC_STREAMOFF <VIDIOC_STREAMON>`. - - -@@ -112,6 +117,7 @@ any DMA in progress, an implicit - .. _V4L2-BUF-CAP-SUPPORTS-USERPTR: - .. _V4L2-BUF-CAP-SUPPORTS-DMABUF: - .. _V4L2-BUF-CAP-SUPPORTS-REQUESTS: -+.. _V4L2-BUF-CAP-SUPPORTS-ORPHANED-BUFS: - - .. cssclass:: longtable - -@@ -132,6 +138,11 @@ any DMA in progress, an implicit - * - ``V4L2_BUF_CAP_SUPPORTS_REQUESTS`` - - 0x00000008 - - This buffer type supports :ref:`requests <media-request-api>`. -+ * - ``V4L2_BUF_CAP_SUPPORTS_ORPHANED_BUFS`` -+ - 0x00000010 -+ - The kernel allows calling :ref:`VIDIOC_REQBUFS` while buffers are still -+ mapped or exported via DMABUF. These orphaned buffers will be freed -+ when they are unmapped or when the exported DMABUF fds are closed. - - Return Value - ============ ---- a/drivers/media/common/videobuf2/videobuf2-core.c -+++ b/drivers/media/common/videobuf2/videobuf2-core.c -@@ -684,11 +684,9 @@ int vb2_core_reqbufs(struct vb2_queue *q - * are not in use and can be freed. - */ - mutex_lock(&q->mmap_lock); -- if (q->memory == VB2_MEMORY_MMAP && __buffers_in_use(q)) { -- mutex_unlock(&q->mmap_lock); -- dprintk(1, "memory in use, cannot free\n"); -- return -EBUSY; -- } -+ if (debug && q->memory == VB2_MEMORY_MMAP && -+ __buffers_in_use(q)) -+ dprintk(1, "memory in use, orphaning buffers\n"); - - /* - * Call queue_cancel to clean up any buffers in the PREPARED or ---- a/drivers/media/common/videobuf2/videobuf2-v4l2.c -+++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c -@@ -484,7 +484,7 @@ EXPORT_SYMBOL(vb2_querybuf); - - static void fill_buf_caps(struct vb2_queue *q, u32 *caps) - { -- *caps = 0; -+ *caps = V4L2_BUF_CAP_SUPPORTS_ORPHANED_BUFS; - if (q->io_modes & VB2_MMAP) - *caps |= V4L2_BUF_CAP_SUPPORTS_MMAP; - if (q->io_modes & VB2_USERPTR) ---- a/include/uapi/linux/videodev2.h -+++ b/include/uapi/linux/videodev2.h -@@ -881,6 +881,7 @@ struct v4l2_requestbuffers { - #define V4L2_BUF_CAP_SUPPORTS_USERPTR (1 << 1) - #define V4L2_BUF_CAP_SUPPORTS_DMABUF (1 << 2) - #define V4L2_BUF_CAP_SUPPORTS_REQUESTS (1 << 3) -+#define V4L2_BUF_CAP_SUPPORTS_ORPHANED_BUFS (1 << 4) - - /** - * struct v4l2_plane - plane info for multi-planar buffers |