From b6a36e5ddf8496ec83a14589f32f58bbaf022046 Mon Sep 17 00:00:00 2001 From: Dave Airlie Date: Fri, 15 Mar 2019 11:46:21 +1000 Subject: [PATCH] drm/fb: avoid setting 0 depth. If the downscaling fails and we end up with a best_depth of 0, then ignore it. This actually works around a cascade of failure, but it the simplest fix for now. The scaling patch broke the udl driver, as the udl driver doesn't expose planes at all, so gets the two default 32-bit formats, but the udl driver then ask for 16bpp fbdev, and the scaling code falls over. This fixes the udl driver since the scaled depth support was added. Fixes: f4bd542bcaee ("drm/fb-helper: Scale back depth to supported maximum") Cc: Daniel Vetter Reviewed-by: Linus Walleij Signed-off-by: Dave Airlie Link: https://patchwork.freedesktop.org/patch/msgid/20190315014621.21816-2-airlied@gmail.com --- drivers/gpu/drm/drm_fb_helper.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c index 0e9349ff2d16..af2ab640cadb 100644 --- a/drivers/gpu/drm/drm_fb_helper.c +++ b/drivers/gpu/drm/drm_fb_helper.c @@ -1963,7 +1963,7 @@ static int drm_fb_helper_single_fb_probe(struct drm_fb_helper *fb_helper, best_depth = fmt->depth; } } - if (sizes.surface_depth != best_depth) { + if (sizes.surface_depth != best_depth && best_depth) { DRM_INFO("requested bpp %d, scaled depth down to %d", sizes.surface_bpp, best_depth); sizes.surface_depth = best_depth;