Commit 62a4cd01 authored by Sergey Senozhatsky's avatar Sergey Senozhatsky Committed by Mauro Carvalho Chehab
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media: vivid: add cache_hints module param 



Add a cache_hints module param to control per-queue user space cache
hints support.

Signed-off-by: default avatarSergey Senozhatsky <senozhatsky@chromium.org>
Signed-off-by: default avatarHans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab+huawei@kernel.org>
parent 2ff99ca4

Documentation/admin-guide/media/vivid.rst

+9 −0
Original line number Diff line number Diff line
@@ -293,6 +293,15 @@ all configurable using the following module options: 
		- 0: vmalloc

		- 1: dma-contig



- cache_hints:



	specifies if the device should set queues' user-space cache and memory

	consistency hint capability (V4L2_BUF_CAP_SUPPORTS_MMAP_CACHE_HINTS).

	The hints are valid only when using MMAP streaming I/O. Default is 0.



		- 0: forbid hints

		- 1: allow hints



Taken together, all these module options allow you to precisely customize

the driver behavior and test your application with all sorts of permutations.

It is also very suitable to emulate hardware that is not yet available, e.g.

drivers/media/test-drivers/vivid/vivid-core.c

+9 −0
Original line number Diff line number Diff line
@@ -169,6 +169,14 @@ MODULE_PARM_DESC(allocators, " memory allocator selection, default is 0.\n" 
			     "\t\t    0 == vmalloc\n"

			     "\t\t    1 == dma-contig");



static unsigned int cache_hints[VIVID_MAX_DEVS] = {

	[0 ... (VIVID_MAX_DEVS - 1)] = 0

};

module_param_array(cache_hints, uint, NULL, 0444);

MODULE_PARM_DESC(cache_hints, " user-space cache hints, default is 0.\n"

			     "\t\t    0 == forbid\n"

			     "\t\t    1 == allow");



static struct vivid_dev *vivid_devs[VIVID_MAX_DEVS];



const struct v4l2_rect vivid_min_rect = {
@@ -819,6 +827,7 @@ static int vivid_create_queue(struct vivid_dev *dev, 
	q->lock = &dev->mutex;

	q->dev = dev->v4l2_dev.dev;

	q->supports_requests = true;

	q->allow_cache_hints = (cache_hints[dev->inst] == 1);



	return vb2_queue_init(q);

}