Re: [PATCH v4 0/2] Allow non-coherent video capture buffers on Rockchip ISP V1

From: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
To: Mikhail Rudenko <mike.rudenko@gmail.com>
Cc: Dafna Hirschfeld <dafna@fastmail.com>,
	 Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
	Mauro Carvalho Chehab <mchehab@kernel.org>,
	 Heiko Stuebner <heiko@sntech.de>,
	Tomasz Figa <tfiga@chromium.org>,
	 Marek Szyprowski <m.szyprowski@samsung.com>,
	Hans Verkuil <hverkuil@xs4all.nl>,
	 Sergey Senozhatsky <senozhatsky@chromium.org>,
	linux-media@vger.kernel.org, linux-rockchip@lists.infradead.org,
	 linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org,
	 Mauro Carvalho Chehab <mchehab+huawei@kernel.org>,
	stable@vger.kernel.org
Subject: Re: [PATCH v4 0/2] Allow non-coherent video capture buffers on Rockchip ISP V1
Date: Mon, 23 Mar 2026 17:03:00 +0100	[thread overview]
Message-ID: <acFkAPreOFBvoHid@zed> (raw)
In-Reply-To: <20250303-b4-rkisp-noncoherent-v4-0-e32e843fb6ef@gmail.com>

Hello

On Mon, Mar 03, 2025 at 02:40:08PM +0300, Mikhail Rudenko wrote:
> This small series adds support for non-coherent video capture buffers
> on Rockchip ISP V1. Patch 1 fixes cache management for dmabuf's
> allocated by dma-contig allocator. Patch 2 allows non-coherent
> allocations on the rkisp1 capture queue. Some timing measurements are
> provided in the commit message of patch 2.
>
> Signed-off-by: Mikhail Rudenko <mike.rudenko@gmail.com>

I regularly get back to this series everytime I have to reason about
the caching policies in vb2..

Is there any reason why it didn't get in ?

> ---
> Changes in v4:
> - rebase to media/next
> - use `direction` instead of `buf->dma_dir` in dma_sync_sgtable_*
> - Link to v3: https://lore.kernel.org/r/20250128-b4-rkisp-noncoherent-v3-0-baf39c997d2a@gmail.com
>
> Changes in v3:
> - ignore skip_cache_sync_* flags in vb2_dc_dmabuf_ops_{begin,end}_cpu_access
> - invalidate/flush kernel mappings as appropriate if they exist
> - use dma_sync_sgtable_* instead of dma_sync_sg_*
> - Link to v2: https://lore.kernel.org/r/20250115-b4-rkisp-noncoherent-v2-0-0853e1a24012@gmail.com
>
> Changes in v2:
> - Fix vb2_dc_dmabuf_ops_{begin,end}_cpu_access() for non-coherent buffers.
> - Add cache management timing information to patch 2 commit message.
> - Link to v1: https://lore.kernel.org/r/20250102-b4-rkisp-noncoherent-v1-1-bba164f7132c@gmail.com
>
> ---
> Mikhail Rudenko (2):
>       media: videobuf2: Fix dmabuf cache sync/flush in dma-contig
>       media: rkisp1: Allow non-coherent video capture buffers
>
>  .../media/common/videobuf2/videobuf2-dma-contig.c  | 22 ++++++++++++++++++++++
>  .../platform/rockchip/rkisp1/rkisp1-capture.c      |  1 +
>  2 files changed, 23 insertions(+)
> ---
> base-commit: b2c4bf0c102084e77ed1b12090d77a76469a6814
> change-id: 20241231-b4-rkisp-noncoherent-ad6e7c7a68ba
>
> Best regards,
> --
> Mikhail Rudenko <mike.rudenko@gmail.com>
>
>