On Tue, 07 Feb 2023, Ville Syrjälä <[email protected]> wrote: > On Tue, Feb 07, 2023 at 01:16:26PM +0200, Jani Nikula wrote: >> With backlight controller set to -1 in intel_panel_init_alloc() to >> distinguish uninitialized values, and controller later being set only if >> it's present in VBT, we can end up with -1 for the controller: >> >> [drm:intel_bios_init_panel [i915]] VBT backlight PWM modulation >> frequency 200 Hz, active high, min brightness 0, level 255, >> controller 4294967295 >> >> There's no harm if it happens on platforms that ignore controller due to >> only one backlight controller being present, like on VLV above, but play >> it safe. >> >> Fixes: bf38bba3e7d6 ("drm/i915: Try to use the correct power sequencer >> intiially on bxt/glk") >> Cc: Ville Syrjälä <[email protected]> >> Signed-off-by: Jani Nikula <[email protected]> >> --- >> drivers/gpu/drm/i915/display/intel_bios.c | 1 + >> 1 file changed, 1 insertion(+) >> >> diff --git a/drivers/gpu/drm/i915/display/intel_bios.c >> b/drivers/gpu/drm/i915/display/intel_bios.c >> index e6ca51232dcf..ad833069f59c 100644 >> --- a/drivers/gpu/drm/i915/display/intel_bios.c >> +++ b/drivers/gpu/drm/i915/display/intel_bios.c >> @@ -1033,6 +1033,7 @@ parse_lfp_backlight(struct drm_i915_private *i915, >> } >> >> panel->vbt.backlight.type = INTEL_BACKLIGHT_DISPLAY_DDI; >> + panel->vbt.backlight.controller = 0; >> if (i915->display.vbt.version >= 191) { >> size_t exp_size; > > Ah right, older VBT didnt have this so we leave it untouched. > Zeroing in that case seems like the right thing to do. > > Reviewed-by: Ville Syrjälä <[email protected]>
Thanks, pushed to din. BR, Jani. -- Jani Nikula, Intel Open Source Graphics Center
