From: Dafna Hirschfeld <dafna.hirschfeld@collabora.com>
To: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>,
linux-media@vger.kernel.org
Cc: linux-renesas-soc@vger.kernel.org,
Helen Koike <helen.koike@collabora.com>,
Shuah Khan <skhan@linuxfoundation.org>
Subject: Re: [PATCH] media: vimc: Add support for contiguous DMA buffers
Date: Fri, 30 Jul 2021 14:35:20 +0200 [thread overview]
Message-ID: <40a1fed8-456e-97c5-9aa7-715a4a4c816b@collabora.com> (raw)
In-Reply-To: <20210730001939.30769-1-laurent.pinchart+renesas@ideasonboard.com>
Hi
On 30.07.21 02:19, Laurent Pinchart wrote:
> The vimc driver is used for testing purpose, and some test use cases
> involve sharing buffers with a consumer device. Consumers often require
> DMA contiguous memory, which vimc doesn't currently support. This leads
> in the best case to usage of bounce buffers, which is very slow, and in
> the worst case in a complete failure.
>
> Add support for the dma-contig allocator in vimc to support those use
> cases properly. The allocator is selected through a new "allocator"
> module parameter, which defaults to vmalloc.
>
> Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
> ---
> drivers/media/test-drivers/vimc/vimc-capture.c | 9 +++++++--
> drivers/media/test-drivers/vimc/vimc-common.h | 2 ++
> drivers/media/test-drivers/vimc/vimc-core.c | 10 ++++++++++
> 3 files changed, 19 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/media/test-drivers/vimc/vimc-capture.c b/drivers/media/test-drivers/vimc/vimc-capture.c
> index 5e9fd902cd37..92b69a6529fb 100644
> --- a/drivers/media/test-drivers/vimc/vimc-capture.c
> +++ b/drivers/media/test-drivers/vimc/vimc-capture.c
> @@ -7,6 +7,7 @@
>
> #include <media/v4l2-ioctl.h>
> #include <media/videobuf2-core.h>
> +#include <media/videobuf2-dma-contig.h>
> #include <media/videobuf2-vmalloc.h>
>
> #include "vimc-common.h"
> @@ -423,14 +424,18 @@ static struct vimc_ent_device *vimc_cap_add(struct vimc_device *vimc,
> /* Initialize the vb2 queue */
> q = &vcap->queue;
> q->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
> - q->io_modes = VB2_MMAP | VB2_DMABUF | VB2_USERPTR;
> + q->io_modes = VB2_MMAP | VB2_DMABUF;
maybe to be on the safe side VB2_DMABUF should be set only if vimc_allocator==1 ?
> + if (vimc_allocator != 1)
maybe define a macro instead of `1` ?
> + q->io_modes |= VB2_USERPTR;
> q->drv_priv = vcap;
> q->buf_struct_size = sizeof(struct vimc_cap_buffer);
> q->ops = &vimc_cap_qops;
> - q->mem_ops = &vb2_vmalloc_memops;
> + q->mem_ops = vimc_allocator == 1
> + ? &vb2_dma_contig_memops : &vb2_vmalloc_memops;
> q->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
> q->min_buffers_needed = 2;
> q->lock = &vcap->lock;
> + q->dev = v4l2_dev->dev;
>
> ret = vb2_queue_init(q);
> if (ret) {
> diff --git a/drivers/media/test-drivers/vimc/vimc-common.h b/drivers/media/test-drivers/vimc/vimc-common.h
> index a289434e75ba..b77939123501 100644
> --- a/drivers/media/test-drivers/vimc/vimc-common.h
> +++ b/drivers/media/test-drivers/vimc/vimc-common.h
> @@ -35,6 +35,8 @@
>
> #define VIMC_PIX_FMT_MAX_CODES 8
>
> +extern unsigned int vimc_allocator;
> +
> /**
> * vimc_colorimetry_clamp - Adjust colorimetry parameters
> *
> diff --git a/drivers/media/test-drivers/vimc/vimc-core.c b/drivers/media/test-drivers/vimc/vimc-core.c
> index 4b0ae6f51d76..7badcecb7aed 100644
> --- a/drivers/media/test-drivers/vimc/vimc-core.c
> +++ b/drivers/media/test-drivers/vimc/vimc-core.c
> @@ -5,6 +5,7 @@
> * Copyright (C) 2015-2017 Helen Koike <helen.fornazier@gmail.com>
> */
>
> +#include <linux/dma-mapping.h>
> #include <linux/font.h>
> #include <linux/init.h>
> #include <linux/module.h>
> @@ -15,6 +16,12 @@
>
> #include "vimc-common.h"
>
> +unsigned int vimc_allocator;
> +module_param_named(allocator, vimc_allocator, uint, 0444);
> +MODULE_PARM_DESC(allocator, " memory allocator selection, default is 0.\n"
> + "\t\t 0 == vmalloc\n"
> + "\t\t 1 == dma-contig");
> +
There is a section 'Module options' in vimc.rst. So a doc should be added there.
Thanks,
Dafna
> #define VIMC_MDEV_MODEL_NAME "VIMC MDEV"
>
> #define VIMC_ENT_LINK(src, srcpad, sink, sinkpad, link_flags) { \
> @@ -278,6 +285,9 @@ static int vimc_probe(struct platform_device *pdev)
>
> tpg_set_font(font->data);
>
> + if (vimc_allocator == 1)
> + dma_coerce_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
> +
> vimc = kzalloc(sizeof(*vimc), GFP_KERNEL);
> if (!vimc)
> return -ENOMEM;
>
next prev parent reply other threads:[~2021-07-30 12:35 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-30 0:19 [PATCH] media: vimc: Add support for contiguous DMA buffers Laurent Pinchart
2021-07-30 12:35 ` Dafna Hirschfeld [this message]
2021-07-30 13:11 ` Laurent Pinchart
2021-07-30 14:08 ` Dafna Hirschfeld
2021-07-30 14:15 ` Laurent Pinchart
2021-07-30 15:59 ` Nicolas Dufresne
2021-07-30 16:56 ` Laurent Pinchart
2021-07-30 15:56 ` Nicolas Dufresne
2021-07-30 16:13 ` Ezequiel Garcia
2021-07-30 16:50 ` Laurent Pinchart
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=40a1fed8-456e-97c5-9aa7-715a4a4c816b@collabora.com \
--to=dafna.hirschfeld@collabora.com \
--cc=helen.koike@collabora.com \
--cc=laurent.pinchart+renesas@ideasonboard.com \
--cc=linux-media@vger.kernel.org \
--cc=linux-renesas-soc@vger.kernel.org \
--cc=skhan@linuxfoundation.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).