Re: [PATCH 3/4] drm-bridge: lontium lt9611c: fixes and improvements

From: Mohit Dsor

Date: Mon Jun 22 2026 - 08:09:12 EST


On Fri, Jun 12, 2026 at 11:26:34AM +0200, Luca Ceresoli wrote:
> On Wed Jun 10, 2026 at 11:14 PM CEST, Mohit Dsor wrote:
> > Remove two redundant lt9611c_reset() calls:
> >
> > 1. In lt9611c_bridge_atomic_pre_enable(): a reset is already performed
> > during probe and resume; calling it again on every display enable
> > adds ~440ms of unnecessary latency.
> >
> > 2. At the end of lt9611c_probe(): a reset was already performed earlier
> > in probe before lt9611c_lock(). The second reset is redundant.
> >
> > Also, the DRM HDMI bridge framework requires hdmi_write_hdmi_infoframe and
> > hdmi_clear_hdmi_infoframe callbacks for HDMI vendor-specific infoframe
> > (VSI) support, used for features such as HDR metadata signalling.
> >
> > This patch add stub implementations that return success. Wire them into the bridge
> > function table.
> >
> > Also, Store the chip variant enum value in the of_match_table .data field and
> > retrieve it via of_device_get_match_data() when probing from a DT node.
> > Fall back to i2c_device_id.driver_data for non-DT (e.g. ACPI) probe
> > paths.
> >
> > This is the standard kernel pattern for passing per-compatible data
> > through the OF match table, and avoids relying solely on the I2C device
> > ID table for chip type detection when DT is available.
> >
> > Populate bridge.vendor and bridge.product so the DRM HDMI framework can
> > report the correct manufacturer and product name in the HDMI connector
> > properties (visible via xrandr --prop and related sysfs entries).
> >
> > Signed-off-by: Mohit Dsor <mohit.dsor@xxxxxxxxxxxxxxxx>
>
> These are several unrelated changes and should be separate commits.
>
> Luca
>
> --
> Luca Ceresoli, Bootlin
> Embedded Linux and Kernel engineering
> https://bootlin.com

Hi Luca,
Thanks for the review.
I see your point about separation, but in this case I intended this as a single cohesive update to the driver rather than unrelated changes.

The redundant lt9611c_reset() removals are cleanup to avoid unnecessary latency during enable/probe.
The HDMI VSI infoframe callbacks are required to align with the DRM HDMI bridge framework expectations.
The OF match data change ensures correct chip variant detection when probing via DT.
The bridge vendor/product population improves user-visible HDMI connector reporting.

All of these are small, tightly scoped updates that improve correctness, framework compliance, and observability of the same driver without introducing independent functional changes.
Given that, I felt keeping them together makes the update easier to review in context. However, I can split them if you strongly prefer that.
Regards,
Mohit