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path: root/drivers/media/usb/uvc/uvc_status.c
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Diffstat (limited to 'drivers/media/usb/uvc/uvc_status.c')
-rw-r--r--drivers/media/usb/uvc/uvc_status.c125
1 files changed, 82 insertions, 43 deletions
diff --git a/drivers/media/usb/uvc/uvc_status.c b/drivers/media/usb/uvc/uvc_status.c
index 7518ffce22ed..a78a88c710e2 100644
--- a/drivers/media/usb/uvc/uvc_status.c
+++ b/drivers/media/usb/uvc/uvc_status.c
@@ -6,6 +6,7 @@
* Laurent Pinchart (laurent.pinchart@ideasonboard.com)
*/
+#include <asm/barrier.h>
#include <linux/kernel.h>
#include <linux/input.h>
#include <linux/slab.h>
@@ -18,11 +19,34 @@
* Input device
*/
#ifdef CONFIG_USB_VIDEO_CLASS_INPUT_EVDEV
+
+static bool uvc_input_has_button(struct uvc_device *dev)
+{
+ struct uvc_streaming *stream;
+
+ /*
+ * The device has button events if both bTriggerSupport and
+ * bTriggerUsage are one. Otherwise the camera button does not
+ * exist or is handled automatically by the camera without host
+ * driver or client application intervention.
+ */
+ list_for_each_entry(stream, &dev->streams, list) {
+ if (stream->header.bTriggerSupport == 1 &&
+ stream->header.bTriggerUsage == 1)
+ return true;
+ }
+
+ return false;
+}
+
static int uvc_input_init(struct uvc_device *dev)
{
struct input_dev *input;
int ret;
+ if (!uvc_input_has_button(dev))
+ return 0;
+
input = input_allocate_device();
if (input == NULL)
return -ENOMEM;
@@ -73,38 +97,23 @@ static void uvc_input_report_key(struct uvc_device *dev, unsigned int code,
/* --------------------------------------------------------------------------
* Status interrupt endpoint
*/
-struct uvc_streaming_status {
- u8 bStatusType;
- u8 bOriginator;
- u8 bEvent;
- u8 bValue[];
-} __packed;
-
-struct uvc_control_status {
- u8 bStatusType;
- u8 bOriginator;
- u8 bEvent;
- u8 bSelector;
- u8 bAttribute;
- u8 bValue[];
-} __packed;
-
static void uvc_event_streaming(struct uvc_device *dev,
- struct uvc_streaming_status *status, int len)
+ struct uvc_status *status, int len)
{
- if (len < 3) {
+ if (len <= offsetof(struct uvc_status, bEvent)) {
uvc_dbg(dev, STATUS,
"Invalid streaming status event received\n");
return;
}
if (status->bEvent == 0) {
- if (len < 4)
+ if (len <= offsetof(struct uvc_status, streaming))
return;
+
uvc_dbg(dev, STATUS, "Button (intf %u) %s len %d\n",
status->bOriginator,
- status->bValue[0] ? "pressed" : "released", len);
- uvc_input_report_key(dev, KEY_CAMERA, status->bValue[0]);
+ status->streaming.button ? "pressed" : "released", len);
+ uvc_input_report_key(dev, KEY_CAMERA, status->streaming.button);
} else {
uvc_dbg(dev, STATUS, "Stream %u error event %02x len %d\n",
status->bOriginator, status->bEvent, len);
@@ -131,7 +140,7 @@ static struct uvc_control *uvc_event_entity_find_ctrl(struct uvc_entity *entity,
}
static struct uvc_control *uvc_event_find_ctrl(struct uvc_device *dev,
- const struct uvc_control_status *status,
+ const struct uvc_status *status,
struct uvc_video_chain **chain)
{
list_for_each_entry((*chain), &dev->chains, list) {
@@ -143,7 +152,7 @@ static struct uvc_control *uvc_event_find_ctrl(struct uvc_device *dev,
continue;
ctrl = uvc_event_entity_find_ctrl(entity,
- status->bSelector);
+ status->control.bSelector);
if (ctrl)
return ctrl;
}
@@ -153,7 +162,7 @@ static struct uvc_control *uvc_event_find_ctrl(struct uvc_device *dev,
}
static bool uvc_event_control(struct urb *urb,
- const struct uvc_control_status *status, int len)
+ const struct uvc_status *status, int len)
{
static const char *attrs[] = { "value", "info", "failure", "min", "max" };
struct uvc_device *dev = urb->context;
@@ -161,24 +170,24 @@ static bool uvc_event_control(struct urb *urb,
struct uvc_control *ctrl;
if (len < 6 || status->bEvent != 0 ||
- status->bAttribute >= ARRAY_SIZE(attrs)) {
+ status->control.bAttribute >= ARRAY_SIZE(attrs)) {
uvc_dbg(dev, STATUS, "Invalid control status event received\n");
return false;
}
uvc_dbg(dev, STATUS, "Control %u/%u %s change len %d\n",
- status->bOriginator, status->bSelector,
- attrs[status->bAttribute], len);
+ status->bOriginator, status->control.bSelector,
+ attrs[status->control.bAttribute], len);
/* Find the control. */
ctrl = uvc_event_find_ctrl(dev, status, &chain);
if (!ctrl)
return false;
- switch (status->bAttribute) {
+ switch (status->control.bAttribute) {
case UVC_CTRL_VALUE_CHANGE:
return uvc_ctrl_status_event_async(urb, chain, ctrl,
- status->bValue);
+ status->control.bValue);
case UVC_CTRL_INFO_CHANGE:
case UVC_CTRL_FAILURE_CHANGE:
@@ -214,28 +223,22 @@ static void uvc_status_complete(struct urb *urb)
len = urb->actual_length;
if (len > 0) {
- switch (dev->status[0] & 0x0f) {
+ switch (dev->status->bStatusType & 0x0f) {
case UVC_STATUS_TYPE_CONTROL: {
- struct uvc_control_status *status =
- (struct uvc_control_status *)dev->status;
-
- if (uvc_event_control(urb, status, len))
+ if (uvc_event_control(urb, dev->status, len))
/* The URB will be resubmitted in work context. */
return;
break;
}
case UVC_STATUS_TYPE_STREAMING: {
- struct uvc_streaming_status *status =
- (struct uvc_streaming_status *)dev->status;
-
- uvc_event_streaming(dev, status, len);
+ uvc_event_streaming(dev, dev->status, len);
break;
}
default:
uvc_dbg(dev, STATUS, "Unknown status event type %u\n",
- dev->status[0]);
+ dev->status->bStatusType);
break;
}
}
@@ -259,12 +262,12 @@ int uvc_status_init(struct uvc_device *dev)
uvc_input_init(dev);
- dev->status = kzalloc(UVC_MAX_STATUS_SIZE, GFP_KERNEL);
- if (dev->status == NULL)
+ dev->status = kzalloc(sizeof(*dev->status), GFP_KERNEL);
+ if (!dev->status)
return -ENOMEM;
dev->int_urb = usb_alloc_urb(0, GFP_KERNEL);
- if (dev->int_urb == NULL) {
+ if (!dev->int_urb) {
kfree(dev->status);
return -ENOMEM;
}
@@ -281,7 +284,7 @@ int uvc_status_init(struct uvc_device *dev)
interval = fls(interval) - 1;
usb_fill_int_urb(dev->int_urb, dev->udev, pipe,
- dev->status, UVC_MAX_STATUS_SIZE, uvc_status_complete,
+ dev->status, sizeof(*dev->status), uvc_status_complete,
dev, interval);
return 0;
@@ -309,5 +312,41 @@ int uvc_status_start(struct uvc_device *dev, gfp_t flags)
void uvc_status_stop(struct uvc_device *dev)
{
+ struct uvc_ctrl_work *w = &dev->async_ctrl;
+
+ /*
+ * Prevent the asynchronous control handler from requeing the URB. The
+ * barrier is needed so the flush_status change is visible to other
+ * CPUs running the asynchronous handler before usb_kill_urb() is
+ * called below.
+ */
+ smp_store_release(&dev->flush_status, true);
+
+ /*
+ * Cancel any pending asynchronous work. If any status event was queued,
+ * process it synchronously.
+ */
+ if (cancel_work_sync(&w->work))
+ uvc_ctrl_status_event(w->chain, w->ctrl, w->data);
+
+ /* Kill the urb. */
usb_kill_urb(dev->int_urb);
+
+ /*
+ * The URB completion handler may have queued asynchronous work. This
+ * won't resubmit the URB as flush_status is set, but it needs to be
+ * cancelled before returning or it could then race with a future
+ * uvc_status_start() call.
+ */
+ if (cancel_work_sync(&w->work))
+ uvc_ctrl_status_event(w->chain, w->ctrl, w->data);
+
+ /*
+ * From this point, there are no events on the queue and the status URB
+ * is dead. No events will be queued until uvc_status_start() is called.
+ * The barrier is needed to make sure that flush_status is visible to
+ * uvc_ctrl_status_event_work() when uvc_status_start() will be called
+ * again.
+ */
+ smp_store_release(&dev->flush_status, false);
}
generated by cgit v1.2.3 (git 2.39.0) at 2024-07-26 08:12:07 +0300