[PATCH i-g-t v1 1/3] lib/igt_kms: Add mode restriction check for Intel scaling

[B, Jeevan]

> -----Original Message-----
> From: igt-dev <igt-dev-bounces at lists.freedesktop.org> On Behalf Of Naladala
> Ramanaidu
> Sent: Friday, March 28, 2025 2:23 AM
> To: igt-dev at lists.freedesktop.org
> Cc: Sharma, Swati2 <swati2.sharma at intel.com>; Naladala, Ramanaidu
> <ramanaidu.naladala at intel.com>
> Subject: [PATCH i-g-t v1 1/3] lib/igt_kms: Add mode restriction check for Intel
> scaling
> 
> Add function to verify display mode parameters (horizontal resolution, vertical
> resolution, refresh rate) within 4K limits for scaling operation.
> 
> Signed-off-by: Naladala Ramanaidu <ramanaidu.naladala at intel.com>
> ---
>  lib/igt_kms.c | 23 +++++++++++++++++++++++  lib/igt_kms.h |  1 +
>  2 files changed, 24 insertions(+)
> 
> diff --git a/lib/igt_kms.c b/lib/igt_kms.c index 99c8707c7..332f6dbf3 100644
> --- a/lib/igt_kms.c
> +++ b/lib/igt_kms.c
> @@ -93,6 +93,10 @@
>  #define MAX_EDID 2
>  #define DISPLAY_TILE_BLOCK 0x12
> 
> +#define HDISPLAY_SCALING_MAX 3840
> +#define VDISPLAY_SCALING_MAX 2160
> +#define VREFRESH_SCALING_MAX 60

Can you please mention the spec number or Kernel patch where we have this restrictions mentioned ? 

> +
>  typedef bool (*igt_connector_attr_set)(int dir, const char *attr, const char
> *value);
> 
>  struct igt_connector_attr {
> @@ -6998,6 +7002,25 @@ int get_num_scalers(igt_display_t *display, enum pipe
> pipe)
>  	return num_scalers;
>  }
> 
> +/**
> + * is_intel_support_scaling:
> + * @drmModeModeInfo *mode: Pointer to a structure with display mode
> information.
> + *
> + * Finds the display mode's horizontal resolution, vertical resolution,
> +and refresh
> + * rate are within the specified maximum limits.
> + *
> + * Returns: true on success, false  on failure  */ bool
> +is_intel_support_scaling(drmModeModeInfo *mode) {
> +	if ((mode->hdisplay <= HDISPLAY_SCALING_MAX) &&
> +	    (mode->vdisplay <= VDISPLAY_SCALING_MAX) &&
> +	    (mode->vrefresh <= VREFRESH_SCALING_MAX))
> +		return true;
> +
> +	return false;
> +}
> +
>  /**
>   * igt_parse_marked_value:
>   * @buf: Buffer containing the content to parse diff --git a/lib/igt_kms.h
> b/lib/igt_kms.h index 0381c82ad..0e3d1297d 100644
> --- a/lib/igt_kms.h
> +++ b/lib/igt_kms.h
> @@ -1279,5 +1279,6 @@ void igt_set_link_params(int drm_fd, igt_output_t
> *output,
>  			   char *link_rate, char *lane_count);  int
> igt_backlight_read(int *result, const char *fname, igt_backlight_context_t
> *context);  int igt_backlight_write(int value, const char *fname,
> igt_backlight_context_t *context);
> +bool is_intel_support_scaling(drmModeModeInfo *mode);
> 
>  #endif /* __IGT_KMS_H__ */
> --
> 2.43.0