[ Upstream commit d99004d7201aa653658ff2390d6e516567c96ebc ] I. was. blind. Caught with vkms, which has some really slow crc computation function. Fixes: 1882018a70e0 ("drm/crc-debugfs: User irqsafe spinlock in drm_crtc_add_crc_entry") Cc: Rodrigo Siqueira <rodrigosiqueiramelo@xxxxxxxxx> Cc: Tomeu Vizoso <tomeu.vizoso@xxxxxxxxxxxxx> Cc: Emil Velikov <emil.velikov@xxxxxxxxxxxxx> Cc: Benjamin Gaignard <benjamin.gaignard@xxxxxxxxxx> Cc: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> Reviewed-by: Emil Velikov <emil.velikov@xxxxxxxxxxxxx> Reviewed-by: Benjamin Gaignard <benjamin.gaignard@xxxxxxxxxx> Signed-off-by: Daniel Vetter <daniel.vetter@xxxxxxxxx> Link: https://patchwork.freedesktop.org/patch/msgid/20190606211544.5389-1-daniel.vetter@xxxxxxxx Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/gpu/drm/drm_debugfs_crc.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/drm_debugfs_crc.c b/drivers/gpu/drm/drm_debugfs_crc.c index a334a82fcb36..c88e5ff41add 100644 --- a/drivers/gpu/drm/drm_debugfs_crc.c +++ b/drivers/gpu/drm/drm_debugfs_crc.c @@ -385,7 +385,7 @@ int drm_crtc_add_crc_entry(struct drm_crtc *crtc, bool has_frame, /* Caller may not have noticed yet that userspace has stopped reading */ if (!crc->entries) { - spin_unlock(&crc->lock); + spin_unlock_irqrestore(&crc->lock, flags); return -EINVAL; } @@ -396,7 +396,7 @@ int drm_crtc_add_crc_entry(struct drm_crtc *crtc, bool has_frame, bool was_overflow = crc->overflow; crc->overflow = true; - spin_unlock(&crc->lock); + spin_unlock_irqrestore(&crc->lock, flags); if (!was_overflow) DRM_ERROR("Overflow of CRC buffer, userspace reads too slow.\n"); -- 2.20.1