Re: [PATCH 16/19] drm/i915/crt: Extract intel_crt_sense_above_threshold()

[Jani Nikula <jani.nikula@linux.intel.com>]

On Mon, 08 Dec 2025, Ville Syrjala <ville.syrjala@linux.intel.com> wrote:
> From: Ville Syrjälä <ville.syrjala@linux.intel.com>
>
> Extract the CRT sense check into a helper instead of repeating
> the same thing twice.
>
> Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>

Reviewed-by: Jani Nikula <jani.nikula@intel.com>

> ---
>  drivers/gpu/drm/i915/display/intel_crt.c | 16 +++++++++-------
>  1 file changed, 9 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_crt.c b/drivers/gpu/drm/i915/display/intel_crt.c
> index 6f216ba887bc..b71a8d97cdbb 100644
> --- a/drivers/gpu/drm/i915/display/intel_crt.c
> +++ b/drivers/gpu/drm/i915/display/intel_crt.c
> @@ -693,6 +693,11 @@ static bool intel_crt_detect_ddc(struct drm_connector *connector)
>  	return ret;
>  }
>  
> +static bool intel_crt_sense_above_threshold(struct intel_display *display)
> +{
> +	return intel_vga_read(display, VGA_IS0_R, true) & (1 << 4);
> +}
> +
>  static enum drm_connector_status
>  intel_crt_load_detect(struct intel_crt *crt, enum pipe pipe)
>  {
> @@ -704,7 +709,6 @@ intel_crt_load_detect(struct intel_crt *crt, enum pipe pipe)
>  	u32 vsample;
>  	u32 vblank, vblank_start, vblank_end;
>  	u32 dsl;
> -	u8 st00;
>  	enum drm_connector_status status;
>  
>  	drm_dbg_kms(display->drm, "starting load-detect on CRT\n");
> @@ -738,8 +742,8 @@ intel_crt_load_detect(struct intel_crt *crt, enum pipe pipe)
>  		 * border color for Color info.
>  		 */
>  		intel_crtc_wait_for_next_vblank(intel_crtc_for_pipe(display, pipe));
> -		st00 = intel_vga_read(display, VGA_IS0_R, true);
> -		status = ((st00 & (1 << 4)) != 0) ?
> +
> +		status = intel_crt_sense_above_threshold(display) ?
>  			connector_status_connected :
>  			connector_status_disconnected;
>  
> @@ -779,15 +783,13 @@ intel_crt_load_detect(struct intel_crt *crt, enum pipe pipe)
>  		while ((dsl = intel_de_read(display, PIPEDSL(display, pipe))) <= vsample)
>  			;
>  		/*
> -		 * Watch ST00 for an entire scanline
> +		 * Watch sense for an entire scanline
>  		 */
>  		detect = 0;
>  		count = 0;
>  		do {
>  			count++;
> -			/* Read the ST00 VGA status register */
> -			st00 = intel_vga_read(display, VGA_IS0_R, true);
> -			if (st00 & (1 << 4))
> +			if (intel_crt_sense_above_threshold(display))
>  				detect++;
>  		} while ((intel_de_read(display, PIPEDSL(display, pipe)) == dsl));

-- 
Jani Nikula, Intel