Re: [PATCH 06/12] drm/panic: Pass global module parameters to drm_panic_dispatch()

[Jocelyn Falempe <jfalempe@redhat.com>]

On 18/08/2026 14:28, Thomas Zimmermann wrote:
> Set the panic type and QR version in draw_panic_plane() as a single
> point of truth. Pass the values into the individual drawing functions.
> 
> In the test case, always create a QR code with version 40 (i.e., the
> highest supported version).

Thanks, it looks good to me.

Reviewed-by: Jocelyn Falempe <jfalempe@redhat.com>

> 
> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
> ---
>   drivers/gpu/drm/drm_panic.c            | 39 ++++++++++++++++----------
>   drivers/gpu/drm/tests/drm_panic_test.c |  2 +-
>   2 files changed, 25 insertions(+), 16 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_panic.c b/drivers/gpu/drm/drm_panic.c
> index ede620b27515..12c39217cbcb 100644
> --- a/drivers/gpu/drm/drm_panic.c
> +++ b/drivers/gpu/drm/drm_panic.c
> @@ -657,7 +657,7 @@ static void drm_panic_qr_exit(void)
>   	stream.workspace = NULL;
>   }
>   
> -static int drm_panic_get_qr_code_url(u8 **qr_image)
> +static int drm_panic_get_qr_code_url(u8 **qr_image, unsigned int qr_version)
>   {
>   	struct kmsg_dump_iter iter;
>   	char url[256];
> @@ -672,7 +672,7 @@ static int drm_panic_get_qr_code_url(u8 **qr_image)
>   		return -EINVAL;
>   	url_len = ret;
>   
> -	max_qr_data_size = drm_panic_qr_max_data_size(panic_qr_version, url_len);
> +	max_qr_data_size = drm_panic_qr_max_data_size(qr_version, url_len);
>   	max_kmsg_size = min(MAX_ZLIB_RATIO * max_qr_data_size, sizeof(qrbuf1));
>   
>   	/* get kmsg to buffer 1 */
> @@ -718,11 +718,11 @@ static int drm_panic_get_qr_code_url(u8 **qr_image)
>   				     qrbuf1, sizeof(qrbuf1));
>   }
>   
> -static int drm_panic_get_qr_code_raw(u8 **qr_image)
> +static int drm_panic_get_qr_code_raw(u8 **qr_image, unsigned int qr_version)
>   {
>   	struct kmsg_dump_iter iter;
>   	size_t kmsg_len;
> -	size_t max_kmsg_size = min(drm_panic_qr_max_data_size(panic_qr_version, 0),
> +	size_t max_kmsg_size = min(drm_panic_qr_max_data_size(qr_version, 0),
>   				   sizeof(qrbuf1));
>   
>   	kmsg_dump_rewind(&iter);
> @@ -735,19 +735,20 @@ static int drm_panic_get_qr_code_raw(u8 **qr_image)
>   				     qrbuf2, sizeof(qrbuf2));
>   }
>   
> -static int drm_panic_get_qr_code(u8 **qr_image)
> +static int drm_panic_get_qr_code(u8 **qr_image, unsigned int qr_version)
>   {
>   	if (strlen(CONFIG_DRM_PANIC_SCREEN_QR_CODE_URL) > 0)
> -		return drm_panic_get_qr_code_url(qr_image);
> +		return drm_panic_get_qr_code_url(qr_image, qr_version);
>   	else
> -		return drm_panic_get_qr_code_raw(qr_image);
> +		return drm_panic_get_qr_code_raw(qr_image, qr_version);
>   }
>   
>   /*
>    * Draw the panic message at the center of the screen, with a QR Code
>    */
>   static int _draw_panic_screen_qr_code(struct drm_scanout_buffer *sb,
> -				      u32 fg_color, u32 bg_color)
> +				      u32 fg_color, u32 bg_color,
> +				      unsigned int qr_version)
>   {
>   	const struct font_desc *font = get_default_font(sb->width, sb->height, NULL, NULL);
>   	struct drm_rect r_screen, r_logo, r_msg, r_qr, r_qr_canvas;
> @@ -774,7 +775,7 @@ static int _draw_panic_screen_qr_code(struct drm_scanout_buffer *sb,
>   
>   	max_qr_size = min(3 * sb->width / 4, 3 * sb->height / 4);
>   
> -	qr_width = drm_panic_get_qr_code(&qr_image);
> +	qr_width = drm_panic_get_qr_code(&qr_image, qr_version);
>   	if (qr_width <= 0)
>   		return -ENOSPC;
>   
> @@ -816,9 +817,11 @@ static int _draw_panic_screen_qr_code(struct drm_scanout_buffer *sb,
>   	return 0;
>   }
>   
> -static int draw_panic_screen_qr_code(struct drm_scanout_buffer *sb, u32 fg_color, u32 bg_color)
> +static int draw_panic_screen_qr_code(struct drm_scanout_buffer *sb,
> +				     u32 fg_color, u32 bg_color,
> +				     unsigned int qr_version)
>   {
> -	if (_draw_panic_screen_qr_code(sb, fg_color, bg_color))
> +	if (_draw_panic_screen_qr_code(sb, fg_color, bg_color, qr_version))
>   		draw_panic_screen_user(sb, fg_color, bg_color);
>   	return 0;
>   }
> @@ -891,17 +894,18 @@ static bool drm_panic_is_format_supported(const struct drm_format_info *format)
>   	return drm_draw_can_convert_from_xrgb8888(format->format);
>   }
>   
> -static int draw_panic_dispatch(struct drm_scanout_buffer *sb, u32 fg_color, u32 bg_color)
> +static int draw_panic_dispatch(struct drm_scanout_buffer *sb, enum drm_panic_type panic_type,
> +			       u32 fg_color, u32 bg_color, unsigned int qr_version)
>   {
>   	int ret;
>   
> -	switch (drm_panic_type) {
> +	switch (panic_type) {
>   	case DRM_PANIC_TYPE_KMSG:
>   		ret = draw_panic_screen_kmsg(sb, fg_color, bg_color);
>   		break;
>   #if IS_ENABLED(CONFIG_DRM_PANIC_SCREEN_QR_CODE)
>   	case DRM_PANIC_TYPE_QR:
> -		ret = draw_panic_screen_qr_code(sb, fg_color, bg_color);
> +		ret = draw_panic_screen_qr_code(sb, fg_color, bg_color, qr_version);
>   		break;
>   #endif
>   	case DRM_PANIC_TYPE_USER:
> @@ -951,6 +955,11 @@ static void draw_panic_plane(struct drm_plane *plane, const char *description)
>   #else
>   	u32 bg_color = 0x00000000;
>   #endif
> +#if IS_ENABLED(CONFIG_DRM_PANIC_SCREEN_QR_CODE)
> +	unsigned int qr_version = panic_qr_version;
> +#else
> +	unsigned int qr_version = 0;
> +#endif
>   
>   	if (!drm_panic_trylock(plane->dev, flags))
>   		return;
> @@ -966,7 +975,7 @@ static void draw_panic_plane(struct drm_plane *plane, const char *description)
>   
>   	drm_panic_set_description(description);
>   
> -	ret = draw_panic_dispatch(&sb, fg_color, bg_color);
> +	ret = draw_panic_dispatch(&sb, drm_panic_type, fg_color, bg_color, qr_version);
>   	if (!ret) {
>   		/*
>   		 * Only flush if we have a panic screen to display. Otherwise
> diff --git a/drivers/gpu/drm/tests/drm_panic_test.c b/drivers/gpu/drm/tests/drm_panic_test.c
> index 969a096ec840..196496238d23 100644
> --- a/drivers/gpu/drm/tests/drm_panic_test.c
> +++ b/drivers/gpu/drm/tests/drm_panic_test.c
> @@ -58,7 +58,7 @@ static int draw_panic_screen_kmsg_default(struct drm_scanout_buffer *sb)
>   #if IS_ENABLED(CONFIG_DRM_PANIC_SCREEN_QR_CODE)
>   static int draw_panic_screen_qr_code_default(struct drm_scanout_buffer *sb)
>   {
> -	return draw_panic_screen_qr_code(sb, 0x00ffffff, 0x00000000);
> +	return draw_panic_screen_qr_code(sb, 0x00ffffff, 0x00000000, 40);
>   }
>   #endif
>