[media] v4l: Allow changing control handler lock
Allow choosing the lock used by the control handler. This may be handy
sometimes when a driver providing multiple subdevs does not want to use
several locks to serialise its functions.
Signed-off-by: Sakari Ailus <sakari.ailus@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/video/adp1653.c b/drivers/media/video/adp1653.c
index 24afc99..57e8709 100644
--- a/drivers/media/video/adp1653.c
+++ b/drivers/media/video/adp1653.c
@@ -281,19 +281,19 @@
return -EIO;
}
- mutex_lock(&flash->ctrls.lock);
+ mutex_lock(flash->ctrls.lock);
/* Reset faults before reading new ones. */
flash->fault = 0;
rval = adp1653_get_fault(flash);
- mutex_unlock(&flash->ctrls.lock);
+ mutex_unlock(flash->ctrls.lock);
if (rval > 0) {
dev_err(&client->dev, "faults detected: 0x%1.1x\n", rval);
return -EIO;
}
- mutex_lock(&flash->ctrls.lock);
+ mutex_lock(flash->ctrls.lock);
rval = adp1653_update_hw(flash);
- mutex_unlock(&flash->ctrls.lock);
+ mutex_unlock(flash->ctrls.lock);
if (rval) {
dev_err(&client->dev,
"adp1653_update_hw failed at %s\n", __func__);
diff --git a/drivers/media/video/v4l2-ctrls.c b/drivers/media/video/v4l2-ctrls.c
index edb2a6a..e5531ac 100644
--- a/drivers/media/video/v4l2-ctrls.c
+++ b/drivers/media/video/v4l2-ctrls.c
@@ -1177,7 +1177,8 @@
int v4l2_ctrl_handler_init(struct v4l2_ctrl_handler *hdl,
unsigned nr_of_controls_hint)
{
- mutex_init(&hdl->lock);
+ hdl->lock = &hdl->_lock;
+ mutex_init(hdl->lock);
INIT_LIST_HEAD(&hdl->ctrls);
INIT_LIST_HEAD(&hdl->ctrl_refs);
hdl->nr_of_buckets = 1 + nr_of_controls_hint / 8;
@@ -1198,7 +1199,7 @@
if (hdl == NULL || hdl->buckets == NULL)
return;
- mutex_lock(&hdl->lock);
+ mutex_lock(hdl->lock);
/* Free all nodes */
list_for_each_entry_safe(ref, next_ref, &hdl->ctrl_refs, node) {
list_del(&ref->node);
@@ -1215,7 +1216,7 @@
hdl->buckets = NULL;
hdl->cached = NULL;
hdl->error = 0;
- mutex_unlock(&hdl->lock);
+ mutex_unlock(hdl->lock);
}
EXPORT_SYMBOL(v4l2_ctrl_handler_free);
@@ -1280,9 +1281,9 @@
struct v4l2_ctrl_ref *ref = NULL;
if (hdl) {
- mutex_lock(&hdl->lock);
+ mutex_lock(hdl->lock);
ref = find_ref(hdl, id);
- mutex_unlock(&hdl->lock);
+ mutex_unlock(hdl->lock);
}
return ref;
}
@@ -1329,7 +1330,7 @@
INIT_LIST_HEAD(&new_ref->node);
- mutex_lock(&hdl->lock);
+ mutex_lock(hdl->lock);
/* Add immediately at the end of the list if the list is empty, or if
the last element in the list has a lower ID.
@@ -1359,7 +1360,7 @@
hdl->buckets[bucket] = new_ref;
unlock:
- mutex_unlock(&hdl->lock);
+ mutex_unlock(hdl->lock);
return 0;
}
@@ -1445,9 +1446,9 @@
kfree(ctrl);
return NULL;
}
- mutex_lock(&hdl->lock);
+ mutex_lock(hdl->lock);
list_add_tail(&ctrl->node, &hdl->ctrls);
- mutex_unlock(&hdl->lock);
+ mutex_unlock(hdl->lock);
return ctrl;
}
@@ -1564,7 +1565,7 @@
return 0;
if (hdl->error)
return hdl->error;
- mutex_lock(&add->lock);
+ mutex_lock(add->lock);
list_for_each_entry(ref, &add->ctrl_refs, node) {
struct v4l2_ctrl *ctrl = ref->ctrl;
@@ -1578,7 +1579,7 @@
if (ret)
break;
}
- mutex_unlock(&add->lock);
+ mutex_unlock(add->lock);
return ret;
}
EXPORT_SYMBOL(v4l2_ctrl_add_handler);
@@ -1742,11 +1743,11 @@
len = strlen(prefix);
if (len && prefix[len - 1] != ' ')
colon = ": ";
- mutex_lock(&hdl->lock);
+ mutex_lock(hdl->lock);
list_for_each_entry(ctrl, &hdl->ctrls, node)
if (!(ctrl->flags & V4L2_CTRL_FLAG_DISABLED))
log_ctrl(ctrl, prefix, colon);
- mutex_unlock(&hdl->lock);
+ mutex_unlock(hdl->lock);
}
EXPORT_SYMBOL(v4l2_ctrl_handler_log_status);
@@ -1758,7 +1759,7 @@
if (hdl == NULL)
return 0;
- mutex_lock(&hdl->lock);
+ mutex_lock(hdl->lock);
list_for_each_entry(ctrl, &hdl->ctrls, node)
ctrl->done = false;
@@ -1783,7 +1784,7 @@
if (ret)
break;
}
- mutex_unlock(&hdl->lock);
+ mutex_unlock(hdl->lock);
return ret;
}
EXPORT_SYMBOL(v4l2_ctrl_handler_setup);
@@ -1798,7 +1799,7 @@
if (hdl == NULL)
return -EINVAL;
- mutex_lock(&hdl->lock);
+ mutex_lock(hdl->lock);
/* Try to find it */
ref = find_ref(hdl, id);
@@ -1823,7 +1824,7 @@
break;
}
}
- mutex_unlock(&hdl->lock);
+ mutex_unlock(hdl->lock);
if (!ref)
return -EINVAL;
@@ -2000,7 +2001,7 @@
belong to the same cluster. */
/* This has to be done with the handler lock taken. */
- mutex_lock(&hdl->lock);
+ mutex_lock(hdl->lock);
/* First zero the helper field in the master control references */
for (i = 0; i < cs->count; i++)
@@ -2022,7 +2023,7 @@
/* Point the mref helper to the current helper struct. */
mref->helper = h;
}
- mutex_unlock(&hdl->lock);
+ mutex_unlock(hdl->lock);
return 0;
}
diff --git a/drivers/media/video/vivi.c b/drivers/media/video/vivi.c
index d64d482..6f2e354 100644
--- a/drivers/media/video/vivi.c
+++ b/drivers/media/video/vivi.c
@@ -485,7 +485,7 @@
gen_text(dev, vbuf, line++ * 16, 16, str);
gain = v4l2_ctrl_g_ctrl(dev->gain);
- mutex_lock(&dev->ctrl_handler.lock);
+ mutex_lock(dev->ctrl_handler.lock);
snprintf(str, sizeof(str), " brightness %3d, contrast %3d, saturation %3d, hue %d ",
dev->brightness->cur.val,
dev->contrast->cur.val,
@@ -509,7 +509,7 @@
dev->int_menu->qmenu_int[dev->int_menu->cur.val],
dev->int_menu->cur.val);
gen_text(dev, vbuf, line++ * 16, 16, str);
- mutex_unlock(&dev->ctrl_handler.lock);
+ mutex_unlock(dev->ctrl_handler.lock);
if (dev->button_pressed) {
dev->button_pressed--;
snprintf(str, sizeof(str), " button pressed!");
diff --git a/include/media/v4l2-ctrls.h b/include/media/v4l2-ctrls.h
index c6f6b4c..dde6fba 100644
--- a/include/media/v4l2-ctrls.h
+++ b/include/media/v4l2-ctrls.h
@@ -167,7 +167,9 @@
/** struct v4l2_ctrl_handler - The control handler keeps track of all the
* controls: both the controls owned by the handler and those inherited
* from other handlers.
+ * @_lock: Default for "lock".
* @lock: Lock to control access to this handler and its controls.
+ * May be replaced by the user right after init.
* @ctrls: The list of controls owned by this handler.
* @ctrl_refs: The list of control references.
* @cached: The last found control reference. It is common that the same
@@ -178,7 +180,8 @@
* @error: The error code of the first failed control addition.
*/
struct v4l2_ctrl_handler {
- struct mutex lock;
+ struct mutex _lock;
+ struct mutex *lock;
struct list_head ctrls;
struct list_head ctrl_refs;
struct v4l2_ctrl_ref *cached;
@@ -455,7 +458,7 @@
*/
static inline void v4l2_ctrl_lock(struct v4l2_ctrl *ctrl)
{
- mutex_lock(&ctrl->handler->lock);
+ mutex_lock(ctrl->handler->lock);
}
/** v4l2_ctrl_lock() - Helper function to unlock the handler
@@ -464,7 +467,7 @@
*/
static inline void v4l2_ctrl_unlock(struct v4l2_ctrl *ctrl)
{
- mutex_unlock(&ctrl->handler->lock);
+ mutex_unlock(ctrl->handler->lock);
}
/** v4l2_ctrl_g_ctrl() - Helper function to get the control's value from within a driver.