Motivated by the per-plane locking I've gone through all the get*
ioctls and reduced the locking to the bare minimum required.
v2: Rebase and make it compile ...
v3: Review from Sean:
- Simplify return handling in getplane_res.
- Add a comment to getplane_res that the plane list is invariant and
can be walked locklessly.
v4: Actually git add.
Cc: Sean Paul <seanpaul@xxxxxxxxxxxx>
Reviewed-by: Sean Paul <seanpaul@xxxxxxxxxxxx>
Signed-off-by: Daniel Vetter <daniel.vetter@xxxxxxxxx>
---
drivers/gpu/drm/drm_crtc.c | 58 ++++++++++++++++++----------------------------
1 file changed, 23 insertions(+), 35 deletions(-)
diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
index 3652ed8dda80..2beb219df1bd 100644
--- a/drivers/gpu/drm/drm_crtc.c
+++ b/drivers/gpu/drm/drm_crtc.c
@@ -1743,7 +1743,9 @@ int drm_mode_getresources(struct drm_device *dev, void *data,
card_res->count_fbs = fb_count;
mutex_unlock(&file_priv->fbs_lock);
- drm_modeset_lock_all(dev);
+ /* mode_config.mutex protects the connector list against e.g. DP MST
+ * connector hot-adding. CRTC/Plane lists are invariant. */
+ mutex_lock(&dev->mode_config.mutex);
if (!drm_is_primary_client(file_priv)) {
mode_group = NULL;
@@ -1863,7 +1865,7 @@ int drm_mode_getresources(struct drm_device *dev, void *data,
card_res->count_connectors, card_res->count_encoders);
out:
- drm_modeset_unlock_all(dev);
+ mutex_unlock(&dev->mode_config.mutex);
return ret;
}
@@ -1890,14 +1892,11 @@ int drm_mode_getcrtc(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_resp->crtc_id);
- if (!crtc) {
- ret = -ENOENT;
- goto out;
- }
+ if (!crtc)
+ return -ENOENT;
+ drm_modeset_lock_crtc(crtc, crtc->primary);
crtc_resp->x = crtc->x;
crtc_resp->y = crtc->y;
crtc_resp->gamma_size = crtc->gamma_size;
@@ -1914,9 +1913,8 @@ int drm_mode_getcrtc(struct drm_device *dev,
} else {
crtc_resp->mode_valid = 0;
}
+ drm_modeset_unlock_crtc(crtc);
-out:
- drm_modeset_unlock_all(dev);
return ret;
}
@@ -2100,24 +2098,22 @@ int drm_mode_getencoder(struct drm_device *dev, void *data,
if (!drm_core_check_feature(dev, DRIVER_MODESET))
return -EINVAL;
- drm_modeset_lock_all(dev);
encoder = drm_encoder_find(dev, enc_resp->encoder_id);
- if (!encoder) {
- ret = -ENOENT;
- goto out;
- }
+ if (!encoder)
+ return -ENOENT;
+ drm_modeset_lock(&dev->mode_config.connection_mutex, NULL);
if (encoder->crtc)
enc_resp->crtc_id = encoder->crtc->base.id;
else
enc_resp->crtc_id = 0;
+ drm_modeset_unlock(&dev->mode_config.connection_mutex);
+
enc_resp->encoder_type = encoder->encoder_type;
enc_resp->encoder_id = encoder->base.id;
enc_resp->possible_crtcs = encoder->possible_crtcs;
enc_resp->possible_clones = encoder->possible_clones;
-out:
- drm_modeset_unlock_all(dev);
return ret;
}
@@ -2141,13 +2137,12 @@ int drm_mode_getplane_res(struct drm_device *dev, void *data,
struct drm_mode_config *config;
struct drm_plane *plane;
uint32_t __user *plane_ptr;
- int copied = 0, ret = 0;
+ int copied = 0;
unsigned num_planes;
if (!drm_core_check_feature(dev, DRIVER_MODESET))
return -EINVAL;
- drm_modeset_lock_all(dev);
config = &dev->mode_config;
if (file_priv->universal_planes)
@@ -2163,6 +2158,7 @@ int drm_mode_getplane_res(struct drm_device *dev, void *data,
(plane_resp->count_planes >= num_planes)) {
plane_ptr = (uint32_t __user *)(unsigned long)plane_resp->plane_id_ptr;
+ /* Plane lists are invariant, no locking needed. */
list_for_each_entry(plane, &config->plane_list, head) {
/*
* Unless userspace set the 'universal planes'
@@ -2172,18 +2168,14 @@ int drm_mode_getplane_res(struct drm_device *dev, void *data,
!file_priv->universal_planes)
continue;
- if (put_user(plane->base.id, plane_ptr + copied)) {
- ret = -EFAULT;
- goto out;
- }
+ if (put_user(plane->base.id, plane_ptr + copied))
+ return -EFAULT;
copied++;
}
}
plane_resp->count_planes = num_planes;
-out:
- drm_modeset_unlock_all(dev);
- return ret;
+ return 0;
}
/**
@@ -2210,13 +2202,11 @@ int drm_mode_getplane(struct drm_device *dev, void *data,
if (!drm_core_check_feature(dev, DRIVER_MODESET))
return -EINVAL;
- drm_modeset_lock_all(dev);
plane = drm_plane_find(dev, plane_resp->plane_id);
- if (!plane) {
- ret = -ENOENT;
- goto out;
- }
+ if (!plane)
+ return -ENOENT;
+ drm_modeset_lock(&plane->mutex, NULL);
if (plane->crtc)
plane_resp->crtc_id = plane->crtc->base.id;
else
@@ -2226,6 +2216,7 @@ int drm_mode_getplane(struct drm_device *dev, void *data,
plane_resp->fb_id = plane->fb->base.id;
else
plane_resp->fb_id = 0;
+ drm_modeset_unlock(&plane->mutex);
plane_resp->plane_id = plane->base.id;
plane_resp->possible_crtcs = plane->possible_crtcs;
@@ -2241,14 +2232,11 @@ int drm_mode_getplane(struct drm_device *dev, void *data,
if (copy_to_user(format_ptr,
plane->format_types,
sizeof(uint32_t) * plane->format_count)) {
- ret = -EFAULT;
- goto out;
+ return -EFAULT;
}
}
plane_resp->count_format_types = plane->format_count;
-out:
- drm_modeset_unlock_all(dev);
return ret;
}
--
2.1.1
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