[PATCH v4] drm/fb-helper: Replace bpp/depth parameter by color mode

Maíra Canal mcanal at igalia.com
Fri Jan 6 11:39:22 UTC 2023


On 1/6/23 08:23, Thomas Zimmermann wrote:
> Replace the combination of bpp and depth with a single color-mode
> argument. Handle special cases in simpledrm and ofdrm. Hard-code
> XRGB8888 as fallback format for cases where no given format works.
> 
> The color-mode argument accepts the same values as the kernel's video
> parameter. These are mostly bpp values between 1 and 32. The exceptions
> are 15, which has a color depth of 15 and a bpp value of 16; and 32,
> which has a color depth of 24 and a bpp value of 32.
> 
> v4:
> 	* add back lost test for bpp_specified (Maira)
> 	* add Fixes tag (Daniel)
> v3:
> 	* fix ofdrm build (Maxime)
> v2:
> 	* minimize changes (Daniel)
> 	* use drm_driver_legacy_fb_format() (Daniel)
> 
> Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de>

Tested-by: Maíra Canal <mcanal at igalia.com> # vc4 and vkms

Thanks for taking care of this!

Best Regards,
- Maíra Canal

> Fixes: 37c90d589dc0 ("drm/fb-helper: Fix single-probe color-format selection")
> Cc: Thomas Zimmermann <tzimmermann at suse.de>
> Cc: Javier Martinez Canillas <javierm at redhat.com>
> Cc: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
> Cc: Maxime Ripard <mripard at kernel.org>
> ---
>   drivers/gpu/drm/drm_fb_helper.c  | 42 ++++++++++++++++++--------------
>   drivers/gpu/drm/tiny/ofdrm.c     |  7 +++++-
>   drivers/gpu/drm/tiny/simpledrm.c |  7 +++++-
>   3 files changed, 36 insertions(+), 20 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
> index 1369ca4ae39b..427631706128 100644
> --- a/drivers/gpu/drm/drm_fb_helper.c
> +++ b/drivers/gpu/drm/drm_fb_helper.c
> @@ -1756,24 +1756,21 @@ static uint32_t drm_fb_helper_find_format(struct drm_fb_helper *fb_helper, const
>   	return DRM_FORMAT_INVALID;
>   }
>   
> -static uint32_t drm_fb_helper_find_cmdline_format(struct drm_fb_helper *fb_helper,
> -						  const uint32_t *formats, size_t format_count,
> -						  const struct drm_cmdline_mode *cmdline_mode)
> +static uint32_t drm_fb_helper_find_color_mode_format(struct drm_fb_helper *fb_helper,
> +						     const uint32_t *formats, size_t format_count,
> +						     unsigned int color_mode)
>   {
>   	struct drm_device *dev = fb_helper->dev;
>   	uint32_t bpp, depth;
>   
> -	if (!cmdline_mode->bpp_specified)
> -		return DRM_FORMAT_INVALID;
> -
> -	switch (cmdline_mode->bpp) {
> +	switch (color_mode) {
>   	case 1:
>   	case 2:
>   	case 4:
>   	case 8:
>   	case 16:
>   	case 24:
> -		bpp = depth = cmdline_mode->bpp;
> +		bpp = depth = color_mode;
>   		break;
>   	case 15:
>   		bpp = 16;
> @@ -1784,7 +1781,7 @@ static uint32_t drm_fb_helper_find_cmdline_format(struct drm_fb_helper *fb_helpe
>   		depth = 24;
>   		break;
>   	default:
> -		drm_info(dev, "unsupported bpp value of %d\n", cmdline_mode->bpp);
> +		drm_info(dev, "unsupported color mode of %d\n", color_mode);
>   		return DRM_FORMAT_INVALID;
>   	}
>   
> @@ -1817,10 +1814,13 @@ static int __drm_fb_helper_find_sizes(struct drm_fb_helper *fb_helper, int prefe
>   		drm_client_for_each_connector_iter(connector, &conn_iter) {
>   			struct drm_cmdline_mode *cmdline_mode = &connector->cmdline_mode;
>   
> -			surface_format = drm_fb_helper_find_cmdline_format(fb_helper,
> -									   plane->format_types,
> -									   plane->format_count,
> -									   cmdline_mode);
> +			if (!cmdline_mode->bpp_specified)
> +				continue;
> +
> +			surface_format = drm_fb_helper_find_color_mode_format(fb_helper,
> +									      plane->format_types,
> +									      plane->format_count,
> +									      cmdline_mode->bpp);
>   			if (surface_format != DRM_FORMAT_INVALID)
>   				break; /* found supported format */
>   		}
> @@ -1829,17 +1829,23 @@ static int __drm_fb_helper_find_sizes(struct drm_fb_helper *fb_helper, int prefe
>   		if (surface_format != DRM_FORMAT_INVALID)
>   			break; /* found supported format */
>   
> -		/* try preferred bpp/depth */
> -		surface_format = drm_fb_helper_find_format(fb_helper, plane->format_types,
> -							   plane->format_count, preferred_bpp,
> -							   dev->mode_config.preferred_depth);
> +		/* try preferred color mode */
> +		surface_format = drm_fb_helper_find_color_mode_format(fb_helper,
> +								      plane->format_types,
> +								      plane->format_count,
> +								      preferred_bpp);
>   		if (surface_format != DRM_FORMAT_INVALID)
>   			break; /* found supported format */
>   	}
>   
>   	if (surface_format == DRM_FORMAT_INVALID) {
> +		/*
> +		 * If none of the given color modes works, fall back
> +		 * to XRGB8888. Drivers are expected to provide this
> +		 * format for compatibility with legacy applications.
> +		 */
>   		drm_warn(dev, "No compatible format found\n");
> -		return -EAGAIN;
> +		surface_format = drm_driver_legacy_fb_format(dev, 32, 24);
>   	}
>   
>   	info = drm_format_info(surface_format);
> diff --git a/drivers/gpu/drm/tiny/ofdrm.c b/drivers/gpu/drm/tiny/ofdrm.c
> index 39c5fd463fec..6e349ca42485 100644
> --- a/drivers/gpu/drm/tiny/ofdrm.c
> +++ b/drivers/gpu/drm/tiny/ofdrm.c
> @@ -1352,6 +1352,7 @@ static int ofdrm_probe(struct platform_device *pdev)
>   {
>   	struct ofdrm_device *odev;
>   	struct drm_device *dev;
> +	unsigned int color_mode;
>   	int ret;
>   
>   	odev = ofdrm_device_create(&ofdrm_driver, pdev);
> @@ -1363,7 +1364,11 @@ static int ofdrm_probe(struct platform_device *pdev)
>   	if (ret)
>   		return ret;
>   
> -	drm_fbdev_generic_setup(dev, drm_format_info_bpp(odev->format, 0));
> +	color_mode = drm_format_info_bpp(odev->format, 0);
> +	if (color_mode == 16)
> +		color_mode = odev->format->depth; // can be 15 or 16
> +
> +	drm_fbdev_generic_setup(dev, color_mode);
>   
>   	return 0;
>   }
> diff --git a/drivers/gpu/drm/tiny/simpledrm.c b/drivers/gpu/drm/tiny/simpledrm.c
> index 7355617f38d3..f658b99c796a 100644
> --- a/drivers/gpu/drm/tiny/simpledrm.c
> +++ b/drivers/gpu/drm/tiny/simpledrm.c
> @@ -802,6 +802,7 @@ static int simpledrm_probe(struct platform_device *pdev)
>   {
>   	struct simpledrm_device *sdev;
>   	struct drm_device *dev;
> +	unsigned int color_mode;
>   	int ret;
>   
>   	sdev = simpledrm_device_create(&simpledrm_driver, pdev);
> @@ -813,7 +814,11 @@ static int simpledrm_probe(struct platform_device *pdev)
>   	if (ret)
>   		return ret;
>   
> -	drm_fbdev_generic_setup(dev, drm_format_info_bpp(sdev->format, 0));
> +	color_mode = drm_format_info_bpp(sdev->format, 0);
> +	if (color_mode == 16)
> +		color_mode = sdev->format->depth; // can be 15 or 16
> +
> +	drm_fbdev_generic_setup(dev, color_mode);
>   
>   	return 0;
>   }


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