Re: [PATCH v4 3/3] drm/bridge: megachips: remove bridge when irq request fails

Re: [PATCH v4 3/3] drm/bridge: megachips: remove bridge when irq request fails

[Luca Ceresoli]

On Thu Apr 30, 2026 at 9:56 PM CEST, Osama Abdelkader wrote:
> If devm_request_threaded_irq() fails after drm_bridge_add(), remove the
> bridge before returning.
>
> Keep drm_bridge_add() rather than devm_drm_bridge_add(): registration is
> tied to the STDP4028 device while ge_b850v3_register() may complete from
> either I2C probe; devm would not unwind the bridge if the other client's
> probe fails.

I had a hard time in getting what you mean, until I noticed the global
(ugh) ge_b850v3_lvds_ptr and the two "Only register after both bridges are
probed" checks. Pretty hacky, but definitely for the sake of the fix you're
introducing your patch will be OK.

> Signed-off-by: Osama Abdelkader <osama.abdelkader@gmail.com>
> Fixes: fcfa0ddc18ed ("drm/bridge: Drivers for megachips-stdpxxxx-ge-b850v3-fw (LVDS-DP++)")
> Cc: stable@vger.kernel.org

Reviewed-by: Luca Ceresoli <luca.ceresoli@bootlin.com>

--
Luca Ceresoli, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com

Re: [PATCH v4 3/3] drm/bridge: megachips: remove bridge when irq request fails

[Ian Ray]

On Tue, May 05, 2026 at 05:37:42PM +0200, Luca Ceresoli wrote:
> On Thu Apr 30, 2026 at 9:56 PM CEST, Osama Abdelkader wrote:
> > If devm_request_threaded_irq() fails after drm_bridge_add(), remove the
> > bridge before returning.
> >
> > Keep drm_bridge_add() rather than devm_drm_bridge_add(): registration is
> > tied to the STDP4028 device while ge_b850v3_register() may complete from
> > either I2C probe; devm would not unwind the bridge if the other client's
> > probe fails.
> 
> I had a hard time in getting what you mean, until I noticed the global
> (ugh) ge_b850v3_lvds_ptr and the two "Only register after both bridges are
> probed" checks. Pretty hacky, but definitely for the sake of the fix you're
> introducing your patch will be OK.
> 
> > Signed-off-by: Osama Abdelkader <osama.abdelkader@gmail.com>
> > Fixes: fcfa0ddc18ed ("drm/bridge: Drivers for megachips-stdpxxxx-ge-b850v3-fw (LVDS-DP++)")
> > Cc: stable@vger.kernel.org
> 
> Reviewed-by: Luca Ceresoli <luca.ceresoli@bootlin.com>

Tested boot and hot-plug, no regressions found.  Side-note: an update to
MAINTAINERS has also been accepted [1].
[1] https://lore.kernel.org/all/20260508234835.38732C2BCB0@smtp.kernel.org/

Tested-by: Ian Ray <ian.ray@gehealthcare.com> 

> 
> --
> Luca Ceresoli, Bootlin
> Embedded Linux and Kernel engineering
> https://bootlin.com