Re: (subset) [PATCH 00/72] media: i2c: Reduce cargo-cult

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

On Tue, Aug 12, 2025 at 10:58:30AM +0200, Krzysztof Kozlowski wrote:
> On 12/08/2025 10:51, Laurent Pinchart wrote:
> > On Mon, Aug 11, 2025 at 06:27:01PM -0500, Bjorn Andersson wrote:
> >> On Thu, 10 Jul 2025 20:46:56 +0300, Laurent Pinchart wrote:
> >>> This patch series build on top of Mehdi's introduction of the
> >>> devm_v4l2_sensor_clk_get() helper (see [1]) to drastically reduce
> >>> cargo-cult in camera sensor drivers.
> >>>
> >>> A large number of camera sensor drivers directly use the
> >>> "clock-frequency" property to retrieve the effective or desired external
> >>> clock rate. This is standard behaviour on ACPI platforms that don't
> >>> implement MIPI DisCo for Imaging, but usage of the property has leaked
> >>> to OF-based platforms, due to a combination of historical reasons (using
> >>> "clock-frequency" was initially considered right until before the
> >>> introduction of "assigned-clock-rates") and plain cargo-cult.
> >>>
> >>> [...]
> >>
> >> Applied, thanks!
> >>
> >> [12/72] arm64: dts: qcom: sdm845-db845c-navigation-mezzanine: Replace clock-frequency in camera sensor node
> >>         commit: 5433560caa5e7e677a8d4310bbec08312be765b4
> > 
> > I'm afraid that's too soon. This will introduce a breakage without a
> > corresponding change to the camera sensor driver.
> > 
> > I will post a v2 with the patches reordered. We could merge the V4L2
> > side in a rc1-based stable branch and merge than in the arm-soc tree as
> 
> You cannot ("cannot" as not following the process) merge drivers into
> DTS branch.

Ah, I wasn't aware of that. DTS trees don't allow merging stable
branches shared with other subsystems ? Does it mean that a DTS change
that depends on a driver change always need to be delayed by one kernel
version ?

> > well, but I think we can also delay the .dts changes to the next kernel
> 
> All users of DTS will be anyway affected and commit msg should address that.

Which commit message, the one for the driver changes or the one for the
DTS changes ? I plan in the next version to indicate that the DT changes
depend on the driver changes.

> > version. Do you have a preference ?

-- 
Regards,

Laurent Pinchart