Re: [PATCH v2 00/10] media: Introduce video device state management

Andy Shevchenko <[email protected]> Sat, 20 Sep 2025 13:48:57 +0300

Newsgroups	gmane.linux.ports.tegra,gmane.linux.drivers.video-input-infrastructure,gmane.linux.kernel,gmane.linux.kernel.input,gmane.comp.video.mjpeg.user,gmane.linux.ports.arm.kernel,gmane.comp.hardware.openbmc,gmane.linux.kernel.rpi,gmane.linux.ports.arm.mediatek,gmane.linux.ports.arm.msm,gmane.linux.kernel.renesas-soc,gmane.linux.ports.arm.rockchip,gmane.linux.kernel.samsung-soc,gmane.linux.usb.general
Message-ID	<CAHp75Vfx9kyP-rVtfvyyMK4VH+oiRVjP1fZOtbVH14iLh98Jxw@mail.gmail.com>

On Fri, Sep 19, 2025 at 12:57=E2=80=AFPM Jai Luthra <jai.luthra@ideasonboar=
d.com> wrote:
>
> Hi,
>
> This patch series introduces state management for video devices.
>
> Currently, V4L2 subdevices have a well-established state management
> system [1] that allows the framework to store the subdevice state
> at a central location.
>
> Video devices however lack this, leading to inconsistent state handling
> across drivers and making it difficult to implement features like
> hardware multiplexing in complex media pipelines [2].
>
> The series is composed of three parts:
>
> - Core Infrastructure (PATCH 1-4)
>         Introduces the basic state structure, try state support,
>         initialization callbacks, and driver helpers
> - Framework Integration (PATCH 5-7)
>         Integrates state passing through the ioctl wrappers and driver
>         implementations
> - Driver Examples (PATCH 8-10)
>         Use the state to store formats in TI J721E CSI2RX and Rockchip
>         RKISP1 drivers
>
> This should also provide a foundation for drivers to extend or subclass
> the state structure with device-specific variables in future.
>
> I have tested capture and format negotiation with the converted drivers
> on SK AM62A (j721e-csi2rx) and Debix Model A (rkisp1).
>
> [1]: https://lore.kernel.org/linux-media/20210610145606.3468235-1-tomi.va=
lkeinen-ryLnwIuWjnjg/[email protected]/
> [2]: https://lore.kernel.org/linux-media/20250724-multicontext-mainline-2=
025-v2-0-c9b316773486-ryLnwIuWjnjg/[email protected]/

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With Best Regards,
Andy Shevchenko