Allow uvcvideo compatible devices to allocate their output buffers using
contiguous DMA buffers.
Add the "allocators" module parameter option to let uvcvideo use the
dma-contig instead of vmalloc.
Signed-off-by: Vincent Abriou <vincent.abriou@xxxxxx>
---
Documentation/media/v4l-drivers/uvcvideo.rst | 12 ++++++++++++
drivers/media/usb/uvc/Kconfig | 2 ++
drivers/media/usb/uvc/uvc_driver.c | 3 ++-
drivers/media/usb/uvc/uvc_queue.c | 23 ++++++++++++++++++++---
drivers/media/usb/uvc/uvcvideo.h | 4 ++--
5 files changed, 38 insertions(+), 6 deletions(-)
diff --git a/Documentation/media/v4l-drivers/uvcvideo.rst b/Documentation/media/v4l-drivers/uvcvideo.rst
index d68b3d5..786cff5 100644
--- a/Documentation/media/v4l-drivers/uvcvideo.rst
+++ b/Documentation/media/v4l-drivers/uvcvideo.rst
@@ -7,6 +7,18 @@ driver-specific ioctls and implementation notes.
Questions and remarks can be sent to the Linux UVC development mailing list at
linux-uvc-devel@xxxxxxxxxxxxxxxx.
+Configuring the driver
+----------------------
+
+The driver is configurable using the following module option:
+
+- allocators:
+
+ memory allocator selection, default is 0. It specifies the way buffers
+ will be allocated.
+
+ - 0: vmalloc
+ - 1: dma-contig
Extension Unit (XU) support
---------------------------
diff --git a/drivers/media/usb/uvc/Kconfig b/drivers/media/usb/uvc/Kconfig
index 6ed85efa..71e4d7e 100644
--- a/drivers/media/usb/uvc/Kconfig
+++ b/drivers/media/usb/uvc/Kconfig
@@ -1,7 +1,9 @@
config USB_VIDEO_CLASS
tristate "USB Video Class (UVC)"
depends on VIDEO_V4L2
+ depends on HAS_DMA
select VIDEOBUF2_VMALLOC
+ select VIDEOBUF2_DMA_CONTIG
---help---
Support for the USB Video Class (UVC). Currently only video
input devices, such as webcams, are supported.
diff --git a/drivers/media/usb/uvc/uvc_driver.c b/drivers/media/usb/uvc/uvc_driver.c
index 302e284..1c20aa0 100644
--- a/drivers/media/usb/uvc/uvc_driver.c
+++ b/drivers/media/usb/uvc/uvc_driver.c
@@ -1757,7 +1757,8 @@ static int uvc_register_video(struct uvc_device *dev,
int ret;
/* Initialize the video buffers queue. */
- ret = uvc_queue_init(&stream->queue, stream->type, !uvc_no_drop_param);
+ ret = uvc_queue_init(dev, &stream->queue, stream->type,
+ !uvc_no_drop_param);
if (ret)
return ret;
diff --git a/drivers/media/usb/uvc/uvc_queue.c b/drivers/media/usb/uvc/uvc_queue.c
index 77edd20..5eab146 100644
--- a/drivers/media/usb/uvc/uvc_queue.c
+++ b/drivers/media/usb/uvc/uvc_queue.c
@@ -22,6 +22,7 @@
#include <linux/wait.h>
#include <media/videobuf2-v4l2.h>
#include <media/videobuf2-vmalloc.h>
+#include <media/videobuf2-dma-contig.h>
#include "uvcvideo.h"
@@ -37,6 +38,12 @@
* the driver.
*/
+static unsigned int allocators;
+module_param(allocators, uint, 0444);
+MODULE_PARM_DESC(allocators, " memory allocator selection, default is 0.\n"
+ "\t\t 0 == vmalloc\n"
+ "\t\t 1 == dma-contig");
+
static inline struct uvc_streaming *
uvc_queue_to_stream(struct uvc_video_queue *queue)
{
@@ -188,20 +195,30 @@ static const struct vb2_ops uvc_queue_qops = {
.stop_streaming = uvc_stop_streaming,
};
-int uvc_queue_init(struct uvc_video_queue *queue, enum v4l2_buf_type type,
- int drop_corrupted)
+int uvc_queue_init(struct uvc_device *dev, struct uvc_video_queue *queue,
+ enum v4l2_buf_type type, int drop_corrupted)
{
int ret;
+ static const struct vb2_mem_ops * const uvc_mem_ops[2] = {
+ &vb2_vmalloc_memops,
+ &vb2_dma_contig_memops,
+ };
+
+ if (allocators == 1)
+ dma_coerce_mask_and_coherent(dev->vdev.dev, DMA_BIT_MASK(32));
+ else if (allocators >= ARRAY_SIZE(uvc_mem_ops))
+ allocators = 0;
queue->queue.type = type;
queue->queue.io_modes = VB2_MMAP | VB2_USERPTR | VB2_DMABUF;
queue->queue.drv_priv = queue;
queue->queue.buf_struct_size = sizeof(struct uvc_buffer);
queue->queue.ops = &uvc_queue_qops;
- queue->queue.mem_ops = &vb2_vmalloc_memops;
+ queue->queue.mem_ops = uvc_mem_ops[allocators];
queue->queue.timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC
| V4L2_BUF_FLAG_TSTAMP_SRC_SOE;
queue->queue.lock = &queue->mutex;
+ queue->queue.dev = dev->vdev.dev;
ret = vb2_queue_init(&queue->queue);
if (ret)
return ret;
diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h
index 7e4d3ee..330ba64 100644
--- a/drivers/media/usb/uvc/uvcvideo.h
+++ b/drivers/media/usb/uvc/uvcvideo.h
@@ -632,8 +632,8 @@ extern struct uvc_driver uvc_driver;
extern struct uvc_entity *uvc_entity_by_id(struct uvc_device *dev, int id);
/* Video buffers queue management. */
-extern int uvc_queue_init(struct uvc_video_queue *queue,
- enum v4l2_buf_type type, int drop_corrupted);
+extern int uvc_queue_init(struct uvc_device *dev, struct uvc_video_queue *queue,
+ enum v4l2_buf_type type, int drop_corrupted);
extern void uvc_queue_release(struct uvc_video_queue *queue);
extern int uvc_request_buffers(struct uvc_video_queue *queue,
struct v4l2_requestbuffers *rb);
--
1.9.1
--
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