[PATCH 0/2] Fix I2C-Over-AUX handling

[Lin, Wayne]

[Public]

Sorry for spamming.
Please ignore this patch set. I misread the code flow here a bit. Will refine another version later if needed.

Thanks!

Regards,
Wayne

> -----Original Message-----
> From: Wayne Lin <Wayne.Lin at amd.com>
> Sent: Thursday, April 24, 2025 11:08 AM
> To: dri-devel at lists.freedesktop.org
> Cc: ville.syrjala at linux.intel.com; jani.nikula at intel.com; Limonciello, Mario
> <Mario.Limonciello at amd.com>; Wentland, Harry <Harry.Wentland at amd.com>; Lin,
> Wayne <Wayne.Lin at amd.com>
> Subject: [PATCH 0/2] Fix I2C-Over-AUX handling
>
> These two patches are trying to fix how we handle I2C-Over_AUX transactions when
> sink side can only complte partial data at one time.
>
> We encounter EDID reading error with specific monitor and cause mode list can only
> be lower resolutions. After analysis, the monitor will reply I2C_ACK|AUX_ACK
> followed by a byte indicating the read data length fewer than the requested one.
> Under this case, we should update the request length and request again. Code we
> have today doesn't handle such case.
>
> Meanwhile, how we handle Write_Status_Update_Request for I2C write over AUX
> transactions seems wrong as well. The request format should be address only
> transaction without length and data, and we don't really send it out.
> Further more, it should be constrained for I2C write case only. Not for I2C read
> request.
>
> 1st patch to fix the I2C write problem and 2nd one to fix the I2C read.
>
> ---
> Wayne Lin (2):
>   drm/dp: Correct Write_Status_Update_Request handling
>   drm/dp: Add handling for partially read under I2-readC-over-AUX
>
>  drivers/gpu/drm/display/drm_dp_helper.c | 28 +++++++++++++++++++++----
>  1 file changed, 24 insertions(+), 4 deletions(-)
>
> --
> 2.43.0