This patch enables usb power management in the UVC driver. As cameras
are built into more and more modern laptops it is important that we get
power management for them working.
How-to Test
-----------
0. Apply and recompile with CONFIG_USB_DEBUG
1. Plug in the camera
2. rmmod usb-snd-audio # no pm in usb-snd-audio yet and many cameras
have a mic
3. Locate the device with lsusb
4. Go to its sysfs directory
5. echo "auto" > power/level
6. wait for messages about the device and its root hub being suspended
in syslog. It'll take a few seconds
Signed-off-by: Oliver Neukum <[EMAIL PROTECTED]>
Reviewed-by: Brandon Philips <[EMAIL PROTECTED]>
---
uvc_driver.c | 7 ++++++-
uvc_v4l2.c | 6 ++++++
2 files changed, 12 insertions(+), 1 deletion(-)
Index: uvc/uvc_v4l2.c
===================================================================
--- uvc.orig/uvc_v4l2.c
+++ uvc/uvc_v4l2.c
@@ -413,10 +413,15 @@ static int uvc_v4l2_open(struct inode *i
goto done;
}
+ ret = usb_autopm_get_interface(video->dev->intf);
+ if (ret < 0)
+ goto done;
+
/* Create the device handle. */
handle = kzalloc(sizeof *handle, GFP_KERNEL);
if (handle == NULL) {
ret = -ENOMEM;
+ usb_autopm_put_interface(video->dev->intf);
goto done;
}
@@ -455,6 +460,7 @@ static int uvc_v4l2_release(struct inode
kfree(handle);
file->private_data = NULL;
+ usb_autopm_put_interface(video->dev->intf);
kref_put(&video->dev->kref, uvc_delete);
return 0;
}
Index: uvc/uvc_driver.c
===================================================================
--- uvc.orig/uvc_driver.c
+++ uvc/uvc_driver.c
@@ -678,8 +678,10 @@ static int uvc_parse_streaming(struct uv
format->frame = frame;
ret = uvc_parse_format(dev, streaming, format,
&interval, buffer, buflen);
- if (ret < 0)
+ if (ret < 0) {
+ kfree(format);
return ret;
+ }
frame += format->nframes;
format++;
@@ -1605,6 +1607,8 @@ static int uvc_suspend(struct usb_interf
uvc_trace(UVC_TRACE_SUSPEND, "Suspending interface %u\n",
intf->cur_altsetting->desc.bInterfaceNumber);
+ usb_kill_urb(dev->int_urb);
+
/* Controls are cached on the fly so they don't need to be saved. */
if (intf->cur_altsetting->desc.bInterfaceSubClass == SC_VIDEOCONTROL)
return 0;
@@ -1809,6 +1813,7 @@ struct uvc_driver uvc_driver = {
.suspend = uvc_suspend,
.resume = uvc_resume,
.id_table = uvc_ids,
+ .supports_autosuspend = 1,
},
};
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