From 2c77bb29d3985e73f8c780cfd20fdb2f491943ee Mon Sep 17 00:00:00 2001
From: Daniel Vetter <daniel.vetter@ffwll.ch>
Date: Tue, 28 Mar 2017 09:01:45 +0200
Subject: drm: simplify the locking in the GETCRTC ioctl
No need to grab both plane and crtc locks at the same time, we can do
them one after the other. If userspace races it'll get what it
deserves either way.
This removes another user of drm_modeset_lock_crtc. There's only one
left.
v2: Make sure all access to primary->state is properly protected
(Harry).
Cc: Harry Wentland <harry.wentland@amd.com>
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170328070145.21520-1-daniel.vetter@ffwll.ch
---
drivers/gpu/drm/drm_crtc.c | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)
(limited to 'drivers/gpu/drm/drm_crtc.c')
diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
index 660b4c8715de..55b3da2e2a82 100644
--- a/drivers/gpu/drm/drm_crtc.c
+++ b/drivers/gpu/drm/drm_crtc.c
@@ -406,9 +406,9 @@ int drm_mode_getcrtc(struct drm_device *dev,
if (!crtc)
return -ENOENT;
- drm_modeset_lock_crtc(crtc, crtc->primary);
crtc_resp->gamma_size = crtc->gamma_size;
+ drm_modeset_lock(&crtc->primary->mutex, NULL);
if (crtc->primary->state && crtc->primary->state->fb)
crtc_resp->fb_id = crtc->primary->state->fb->base.id;
else if (!crtc->primary->state && crtc->primary->fb)
@@ -416,9 +416,14 @@ int drm_mode_getcrtc(struct drm_device *dev,
else
crtc_resp->fb_id = 0;
- if (crtc->state) {
+ if (crtc->primary->state) {
crtc_resp->x = crtc->primary->state->src_x >> 16;
crtc_resp->y = crtc->primary->state->src_y >> 16;
+ }
+ drm_modeset_unlock(&crtc->primary->mutex);
+
+ drm_modeset_lock(&crtc->mutex, NULL);
+ if (crtc->state) {
if (crtc->state->enable) {
drm_mode_convert_to_umode(&crtc_resp->mode, &crtc->state->mode);
crtc_resp->mode_valid = 1;
@@ -437,7 +442,7 @@ int drm_mode_getcrtc(struct drm_device *dev,
crtc_resp->mode_valid = 0;
}
}
- drm_modeset_unlock_crtc(crtc);
+ drm_modeset_unlock(&crtc->mutex);
return 0;
}
--
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