[PATCH v3] drm/fb-helper: add virtual screen size check to drm_fb_helper_check_var()

From: Andrey Strachuk
Date: Fri Aug 12 2022 - 07:31:53 EST


Make sure that virtual screen size is not less than physical screen one.

Reviewed-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
Signed-off-by: Andrey Strachuk <strochuk@xxxxxxxxx>
---
drivers/gpu/drm/drm_fb_helper.c | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index 2d4cee6a10ff..ea07c97bc5a9 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -1355,6 +1355,12 @@ int drm_fb_helper_check_var(struct fb_var_screeninfo *var,
(drm_format_info_block_height(fb->format, 0) > 1))
return -EINVAL;

+ /* make sure that virtual resolution >= physical resolution */
+ if (var->xres_virtual < var->xres)
+ var->xres_virtual = var->xres;
+ if (var->yres_virtual < var->yres)
+ var->yres_virtual = var->yres;
+
/*
* Changes struct fb_var_screeninfo are currently not pushed back
* to KMS, hence fail if different settings are requested.
--
2.25.1