From: Dhinakaran Pandiyan Date: Sat, 3 Feb 2018 05:12:58 +0000 (-0800) Subject: drm/tegra: Handle 64-bit return from drm_crtc_vblank_count() X-Git-Tag: v4.17-rc1~185^2~20^2~25 X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=3abe241337993a1e358a67427518af0162c4b769;p=linux.git drm/tegra: Handle 64-bit return from drm_crtc_vblank_count() 570e86963a51 ("drm: Widen vblank count to 64-bits [v3]") changed the return type for drm_crtc_vblank_count() to u64. This could cause potential problems if the return value is used in arithmetic operations with a 32-bit reference HW vblank count. Explicitly typecasting this down to u32 either fixes a potential problem or serves to add clarity in case the implicit typecasting was already correct. Cc: Keith Packard Cc: Thierry Reding Signed-off-by: Dhinakaran Pandiyan Reviewed-by: Keith Packard Acked-by: Thierry Reding Signed-off-by: Rodrigo Vivi Link: https://patchwork.freedesktop.org/patch/msgid/20180203051302.9974-6-dhinakaran.pandiyan@intel.com --- diff --git a/drivers/gpu/drm/tegra/dc.c b/drivers/gpu/drm/tegra/dc.c index b8403ed48285..49df2db2ad46 100644 --- a/drivers/gpu/drm/tegra/dc.c +++ b/drivers/gpu/drm/tegra/dc.c @@ -1359,7 +1359,7 @@ static u32 tegra_dc_get_vblank_counter(struct drm_crtc *crtc) return host1x_syncpt_read(dc->syncpt); /* fallback to software emulated VBLANK counter */ - return drm_crtc_vblank_count(&dc->base); + return (u32)drm_crtc_vblank_count(&dc->base); } static int tegra_dc_enable_vblank(struct drm_crtc *crtc)