This prevents a race between module init and sysfs access (usually only
seen at module reload time, or if somehow your userspace starts fast
enough and pokes at /sys/class/drm while the drivers are still
initializing).
Signed-off-by: Jesse Barnes <jbarnes at virtuousgeek.org>
---
drivers/gpu/drm/drm_sysfs.c | 75 ++++++++++++++++++++++++++++++------------
1 files changed, 53 insertions(+), 22 deletions(-)
diff --git a/drivers/gpu/drm/drm_sysfs.c b/drivers/gpu/drm/drm_sysfs.c
index 0f9ef9b..bb8bbc3 100644
--- a/drivers/gpu/drm/drm_sysfs.c
+++ b/drivers/gpu/drm/drm_sysfs.c
@@ -161,15 +161,20 @@ static ssize_t status_show(struct device *device,
enum drm_connector_status status;
int ret;
+ mutex_lock(&drm_global_mutex);
+
ret = mutex_lock_interruptible(&connector->dev->mode_config.mutex);
if (ret)
- return ret;
+ goto out;
status = connector->funcs->detect(connector, true);
mutex_unlock(&connector->dev->mode_config.mutex);
- return snprintf(buf, PAGE_SIZE, "%s\n",
- drm_get_connector_status_name(status));
+ ret = snprintf(buf, PAGE_SIZE, "%s\n",
+ drm_get_connector_status_name(status));
+out:
+ mutex_unlock(&drm_global_mutex);
+ return ret;
}
static ssize_t dpms_show(struct device *device,
@@ -181,14 +186,20 @@ static ssize_t dpms_show(struct device *device,
uint64_t dpms_status;
int ret;
+ mutex_lock(&drm_global_mutex);
ret = drm_connector_property_get_value(connector,
dev->mode_config.dpms_property,
&dpms_status);
- if (ret)
- return 0;
+ if (ret) {
+ ret = 0;
+ goto out;
+ }
- return snprintf(buf, PAGE_SIZE, "%s\n",
+ ret = snprintf(buf, PAGE_SIZE, "%s\n",
drm_get_dpms_name((int)dpms_status));
+out:
+ mutex_unlock(&drm_global_mutex);
+ return ret;
}
static ssize_t enabled_show(struct device *device,
@@ -196,9 +207,13 @@ static ssize_t enabled_show(struct device *device,
char *buf)
{
struct drm_connector *connector = to_drm_connector(device);
+ int ret;
- return snprintf(buf, PAGE_SIZE, "%s\n", connector->encoder ? "enabled" :
- "disabled");
+ mutex_lock(&drm_global_mutex);
+ ret = snprintf(buf, PAGE_SIZE, "%s\n", connector->encoder ? "enabled" :
+ "disabled");
+ mutex_unlock(&drm_global_mutex);
+ return ret;
}
static ssize_t edid_show(struct file *filp, struct kobject *kobj,
@@ -210,21 +225,30 @@ static ssize_t edid_show(struct file *filp, struct
kobject *kobj,
unsigned char *edid;
size_t size;
- if (!connector->edid_blob_ptr)
- return 0;
+ mutex_lock(&drm_global_mutex);
+ if (!connector->edid_blob_ptr) {
+ count = 0;
+ goto out;
+ }
edid = connector->edid_blob_ptr->data;
size = connector->edid_blob_ptr->length;
- if (!edid)
- return 0;
+ if (!edid) {
+ count = 0;
+ goto out;
+ }
- if (off >= size)
- return 0;
+ if (off >= size) {
+ count = 0;
+ goto out;
+ }
if (off + count > size)
count = size - off;
memcpy(buf, edid + off, count);
+out:
+ mutex_unlock(&drm_global_mutex);
return count;
}
@@ -236,11 +260,12 @@ static ssize_t modes_show(struct device *device,
struct drm_display_mode *mode;
int written = 0;
+ mutex_lock(&drm_global_mutex);
list_for_each_entry(mode, &connector->modes, head) {
written += snprintf(buf + written, PAGE_SIZE - written, "%s\n",
mode->name);
}
-
+ mutex_unlock(&drm_global_mutex);
return written;
}
@@ -253,7 +278,9 @@ static ssize_t subconnector_show(struct device *device,
struct drm_property *prop = NULL;
uint64_t subconnector;
int is_tv = 0;
- int ret;
+ int ret = 0;
+
+ mutex_lock(&drm_global_mutex);
switch (connector->connector_type) {
case DRM_MODE_CONNECTOR_DVII:
@@ -268,21 +295,25 @@ static ssize_t subconnector_show(struct device *device,
break;
default:
DRM_ERROR("Wrong connector type for this property\n");
- return 0;
+ goto out;
}
if (!prop) {
DRM_ERROR("Unable to find subconnector property\n");
- return 0;
+ goto out;
}
ret = drm_connector_property_get_value(connector, prop, &subconnector);
if (ret)
- return 0;
+ goto out;
- return snprintf(buf, PAGE_SIZE, "%s", is_tv ?
- drm_get_tv_subconnector_name((int)subconnector) :
- drm_get_dvi_i_subconnector_name((int)subconnector));
+ ret = snprintf(buf, PAGE_SIZE, "%s", is_tv ?
+ drm_get_tv_subconnector_name((int)subconnector) :
+ drm_get_dvi_i_subconnector_name((int)subconnector));
+
+out:
+ mutex_unlock(&drm_global_mutex);
+ return ret;
}
static ssize_t select_subconnector_show(struct device *device,
--
1.7.5.4
