From 04ee39ba9fff5bf6278328e2da1740001159c4c6 Mon Sep 17 00:00:00 2001 From: Daniel Vetter Date: Mon, 3 Apr 2017 10:32:56 +0200 Subject: [PATCH] drm: Only take crtc lock in get_gamma ioctl We don't call into drivers at all here, this is enough. Also, we can reduce the critical section a bit to simplify the code. crtc->gamma_size is set up once at driver load and then invariant, so also doesn't need any protection. Reviewed-by: Maarten Lankhorst Signed-off-by: Daniel Vetter Link: http://patchwork.freedesktop.org/patch/msgid/20170403083304.9083-8-daniel.vetter@ffwll.ch --- drivers/gpu/drm/drm_color_mgmt.c | 16 ++++++---------- 1 file changed, 6 insertions(+), 10 deletions(-) diff --git a/drivers/gpu/drm/drm_color_mgmt.c b/drivers/gpu/drm/drm_color_mgmt.c index cc23b9a..a32be59 100644 --- a/drivers/gpu/drm/drm_color_mgmt.c +++ b/drivers/gpu/drm/drm_color_mgmt.c @@ -295,19 +295,15 @@ int drm_mode_gamma_get_ioctl(struct drm_device *dev, if (!drm_core_check_feature(dev, DRIVER_MODESET)) return -EINVAL; - drm_modeset_lock_all(dev); crtc = drm_crtc_find(dev, crtc_lut->crtc_id); - if (!crtc) { - ret = -ENOENT; - goto out; - } + if (!crtc) + return -ENOENT; /* memcpy into gamma store */ - if (crtc_lut->gamma_size != crtc->gamma_size) { - ret = -EINVAL; - goto out; - } + if (crtc_lut->gamma_size != crtc->gamma_size) + return -EINVAL; + drm_modeset_lock(&crtc->mutex, NULL); size = crtc_lut->gamma_size * (sizeof(uint16_t)); r_base = crtc->gamma_store; if (copy_to_user((void __user *)(unsigned long)crtc_lut->red, r_base, size)) { @@ -327,6 +323,6 @@ int drm_mode_gamma_get_ioctl(struct drm_device *dev, goto out; } out: - drm_modeset_unlock_all(dev); + drm_modeset_unlock(&crtc->mutex); return ret; } -- 2.7.4