[PATCH v3 1/2] drm/amd/amdgpu/amdgpu_drv.c: Replace drm_modeset_lock_all() with drm_modeset_lock_all_ctx()

[Fabio M. De Francesco]

Replace the deprecated API with new helpers, according to the
TODO list of the DRM subsystem.

In this first patch drm_modeset_lock_all() is replaced with
drm_modeset_lock_all_ctx(). Unlike drm_modeset_lock_all(),
the latter doesn’t take the global drm_mode_config.mutex
since that lock isn’t required for modeset state changes.

Signed-off-by: Fabio M. De Francesco <fmdefrancesco at gmail.com>
---

Changes from v2: The work is split in two consecutive logical steps.
Changes from v1: Added further information to the commit message.

 drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
index 671ec1002230..856903db34c5 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
@@ -1438,8 +1438,15 @@ static int amdgpu_pmops_runtime_idle(struct device *dev)
 
 	if (amdgpu_device_has_dc_support(adev)) {
 		struct drm_crtc *crtc;
-
-		drm_modeset_lock_all(drm_dev);
+		struct drm_modeset_acquire_ctx ctx;
+		int ret_lock = 0;
+
+retry:
+		drm_modeset_lock_all_ctx(drm_dev, &ctx);
+		if(ret_lock == -EDEADLK) {
+			drm_modeset_backoff(&ctx);
+			goto retry;
+		}
 
 		drm_for_each_crtc(crtc, drm_dev) {
 			if (crtc->state->active) {
@@ -1448,7 +1455,7 @@ static int amdgpu_pmops_runtime_idle(struct device *dev)
 			}
 		}
 
-		drm_modeset_unlock_all(drm_dev);
+		drm_modeset_drop_locks(&ctx);
 
 	} else {
 		struct drm_connector *list_connector;
-- 
2.31.1