[PATCH 1/3] drm/i915/dsi: Fix off by one in BXT_MIPI_TRANS_VTOTAL

[Jani Nikula]

On Fri, 04 Apr 2025, Jani Nikula <jani.nikula at linux.intel.com> wrote:
> On Fri, 14 Mar 2025, Ville Syrjala <ville.syrjala at linux.intel.com> wrote:
>> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
>>
>> BXT_MIPI_TRANS_VTOTAL must be programmed with vtotal-1
>> instead of vtotal. Make it so.
>>
>> Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
>
> Reviewed-by: Jani Nikula <jani.nikula at intel.com>

Cc: stable at vger.kernel.org

>
>> ---
>>  drivers/gpu/drm/i915/display/vlv_dsi.c | 4 ++--
>>  1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/display/vlv_dsi.c b/drivers/gpu/drm/i915/display/vlv_dsi.c
>> index af717df83197..661de51dfd22 100644
>> --- a/drivers/gpu/drm/i915/display/vlv_dsi.c
>> +++ b/drivers/gpu/drm/i915/display/vlv_dsi.c
>> @@ -1060,7 +1060,7 @@ static void bxt_dsi_get_pipe_config(struct intel_encoder *encoder,
>>  				              BXT_MIPI_TRANS_VACTIVE(port));
>>  	adjusted_mode->crtc_vtotal =
>>  				intel_de_read(display,
>> -				              BXT_MIPI_TRANS_VTOTAL(port));
>> +				              BXT_MIPI_TRANS_VTOTAL(port)) + 1;
>>  
>>  	hactive = adjusted_mode->crtc_hdisplay;
>>  	hfp = intel_de_read(display, MIPI_HFP_COUNT(display, port));
>> @@ -1265,7 +1265,7 @@ static void set_dsi_timings(struct intel_encoder *encoder,
>>  			intel_de_write(display, BXT_MIPI_TRANS_VACTIVE(port),
>>  				       adjusted_mode->crtc_vdisplay);
>>  			intel_de_write(display, BXT_MIPI_TRANS_VTOTAL(port),
>> -				       adjusted_mode->crtc_vtotal);
>> +				       adjusted_mode->crtc_vtotal - 1);
>>  		}
>>  
>>  		intel_de_write(display, MIPI_HACTIVE_AREA_COUNT(display, port),

-- 
Jani Nikula, Intel