From 235d3e4fa115b39a72112f29ec5c84b847111edd Mon Sep 17 00:00:00 2001 From: Daniel Vetter Date: Tue, 4 Jul 2017 17:18:25 +0200 Subject: [PATCH] drm/fb-helper: Drop locking from the vsync wait ioctl code Like with the drm-native vblank wait ioctl we can entirely rely on the spinlocks in drm_vblank.c, no need at all to take expensive mutexes. The only reason we had to take mode_config.mutex was to protect the fbdev helper's data-structures, but that's now done by fb_helper->lock. Cc: John Stultz Cc: Thierry Reding Reviewed-by: Maarten Lankhorst Signed-off-by: Daniel Vetter Link: http://patchwork.freedesktop.org/patch/msgid/20170704151833.17304-6-daniel.vetter@ffwll.ch --- drivers/gpu/drm/drm_fb_helper.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c index 08a5e0d23a42..9efb17c3cbe8 100644 --- a/drivers/gpu/drm/drm_fb_helper.c +++ b/drivers/gpu/drm/drm_fb_helper.c @@ -1328,7 +1328,6 @@ int drm_fb_helper_ioctl(struct fb_info *info, unsigned int cmd, goto unlock; } - mutex_lock(&dev->mode_config.mutex); switch (cmd) { case FBIO_WAITFORVSYNC: /* @@ -1368,7 +1367,6 @@ int drm_fb_helper_ioctl(struct fb_info *info, unsigned int cmd, } unlock: - mutex_unlock(&dev->mode_config.mutex); mutex_unlock(&fb_helper->lock); return ret; } -- 2.20.1