[PATCH v4 0/6] Add HDMI CEC support to Rockchip RK3588/RK3576 SoCs

[Cristian Ciocaltea]

On 10/28/25 2:42 PM, Cristian Ciocaltea wrote:
> Hi Mark,
> 
> On 10/28/25 2:38 PM, Mark Brown wrote:
>> On Wed, Sep 03, 2025 at 09:50:58PM +0300, Cristian Ciocaltea wrote:
>>> The first patch in the series implements the CEC capability of the
>>> Synopsys DesignWare HDMI QP TX controller found in RK3588 & RK3576 Socs.
>>> This is based on the downstream code, but rewritten on top of the CEC
>>> helpers added recently to the DRM HDMI connector framework.
>>
>> For the past couple of weeks we've been seeing various instability with
>> the graphics drivers on the Rock 5B in -next, the most common system is
>> that we get faults in code that looks suspiciously relevant to this
>> series:
>>
>> <6>[   17.353368] rockchip-drm display-subsystem: bound fdd90000.vop (ops vop2_component_ops [rockchipdrm])
>> <6>[   17.355237] dwhdmiqp-rockchip fde80000.hdmi: registered DesignWare HDMI QP I2C bus driver
>> / # <1>[   17.357803] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000098
>>
>> ...
>>
>> <4>[   17.372390] Hardware name: Radxa ROCK 5B (DT)
>>
>> ...
>>
>> <4>[   17.382082] Call trace:
>> <4>[   17.382317]  drm_bridge_connector_hdmi_cec_init+0x8/0x38 [drm_display_helper] (P)
>> <4>[   17.383003]  drm_bridge_connector_init+0x658/0x678 [drm_display_helper]
>> <4>[   17.383612]  dw_hdmi_qp_rockchip_bind+0x35c/0x4d8 [rockchipdrm]
>> <4>[   17.384159]  component_bind_all+0x118/0x248
>> <4>[   17.384550]  rockchip_drm_bind+0xb4/0x20c [rockchipdrm]
>> <4>[   17.385034]  try_to_bring_up_aggregate_device+0x164/0x1d0
>> <4>[   17.385528]  component_master_add_with_match+0xc4/0x104
>> <4>[   17.386008]  rockchip_drm_platform_probe+0x1f8/0x31c [rockchipdrm]
>>
>> (from today's -next, 
>>
>> Unfortunately we haven't managed to point at a specific commit, it looks
>> like this might be triggered by multiple serieses interacting with each
>> other.  I'm not sure what other information might be useful here?
> 
> Thanks for reporting, I will investigate.

This seems to have been already addressed:

https://lore.kernel.org/all/20251017-drm-bridge-alloc-getput-bridge-connector-fix-hdmi_cec-v2-0-667abf6d47c0@bootlin.com/
> Regards,
> Cristian