Re: [Intel-gfx] [PATCH 0/4] drm/i915/vlv_dsi: Add quirks for x86 android tablets (v2)

["Ville Syrjälä" <ville.syrjala@linux.intel.com>]

On Sat, Sep 16, 2023 at 02:54:51PM +0200, Hans de Goede wrote:
> Hi All,
> 
> Some vlv/chv tablets ship with Android as factory OS. The factory OS
> BSP style kernel on these tablets does not use the normal x86 hw
> autodetection instead it hardcodes a whole bunch of things including
> using panel drivers instead of relying on VBT MIPI sequences to
> turn the panel/backlight on/off.
> 
> The normal i915 driver (which does not use panel drivers) mostly works
> since the VBT still needs to contain valid info for the GOP, but because
> of the Android kernel relying on panel drivers with various things
> hardcoded some DMI quirks are necessary to fix some issues on these
> devices.
> 
> Some of these issues also are related to which I2C bus to use for
> MIPI sequence elements which do I2C transfers. This series also
> includes a patch adding some extra debugging to mipi_exec_i2c() to
> help with debugging similar issues in the future.
> 
> These patches have been posted before but back then I did not get around
> to follow up on the series:
> https://lore.kernel.org/intel-gfx/20220225214934.383168-1-hdegoede@redhat.com/
> 
> Changes compared to this old version:
> - Drop the changes how the I2C bus number is found, instead just have
>   the quirks set the right number directly where necessary. This should
>   avoid any chances of causing regressions on devices where the quirks
>   do not apply.
> 
> - New quirk for backlight control issues on Lenovo Yoga Tab 3
> 
> - Address Jani Nikula's remark about __func__ being redundant when using
>   drm_dbg_kms()
> 
> 
> Regards,
> 
> Hans
> 
> 
> 
> Hans de Goede (4):
>   drm/i915/vlv_dsi: Add DMI quirk for wrong panel modeline in BIOS on
>     Asus TF103C (v2)
>   drm/i915/vlv_dsi: Add DMI quirk for wrong I2C bus and panel size on
>     Lenovo Yoga Tablet 2 series (v2)
>   drm/i915/vlv_dsi: Add DMI quirk for backlight control issues on Lenovo
>     Yoga Tab 3

Please file a bug for each of these and attach the usual drm.debug=0xe
dmesg + VBT + any other relevant information there. Otherwise a few
years from now I'll be cursing at these commits as well for not leaving
a decent papertrail...

>   drm/i915/dsi: Add some debug logging to mipi_exec_i2c (v2)
> 
>  drivers/gpu/drm/i915/display/intel_dsi_vbt.c |   3 +
>  drivers/gpu/drm/i915/display/vlv_dsi.c       | 124 +++++++++++++++++++
>  2 files changed, 127 insertions(+)
> 
> -- 
> 2.41.0

-- 
Ville Syrjälä
Intel