| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-Id: <20220204170745.1269482-3-ribalda@chromium.org>
Date: Fri, 4 Feb 2022 18:07:45 +0100
From: Ricardo Ribalda <ribalda@...omium.org>
To: Laurent Pinchart <laurent.pinchart@...asonboard.com>,
Mauro Carvalho Chehab <mchehab@...nel.org>,
linux-media@...r.kernel.org, linux-kernel@...r.kernel.org,
Tomasz Figa <tfiga@...omium.org>,
Sergey Senozhatsky <senozhatsky@...omium.org>
Cc: Ricardo Ribalda <ribalda@...omium.org>
Subject: [PATCH v4 3/3] media: uvcvideo: Do power management granularly
Instead of suspending/resume the USB device at open()/close(), do it
when the device is actually used.
This way we can reduce the power consumption when a service is holding
the video device and leaving it in an idle state.
Signed-off-by: Ricardo Ribalda <ribalda@...omium.org>
---
drivers/media/usb/uvc/uvc_v4l2.c | 179 +++++++++++++++++++++++++------
1 file changed, 144 insertions(+), 35 deletions(-)
diff --git a/drivers/media/usb/uvc/uvc_v4l2.c b/drivers/media/usb/uvc/uvc_v4l2.c
index ae1f221b2a5d..89bfadbe008b 100644
--- a/drivers/media/usb/uvc/uvc_v4l2.c
+++ b/drivers/media/usb/uvc/uvc_v4l2.c
@@ -25,6 +25,50 @@
#include "uvcvideo.h"
+/* ------------------------------------------------------------------------
+ * UVC power management
+ */
+
+static int uvc_pm_get(struct uvc_streaming *stream)
+{
+ int ret = 0;
+
+ /*
+ * We cannot hold dev->lock when calling autopm_get_interface.
+ * _uvc_resume() takes the same lock.
+ */
+ ret = usb_autopm_get_interface(stream->dev->intf);
+ if (ret)
+ return ret;
+
+ mutex_lock(&stream->dev->lock);
+ if (!stream->dev->users)
+ ret = uvc_status_start(stream->dev, GFP_KERNEL);
+ if (!ret)
+ stream->dev->users++;
+ mutex_unlock(&stream->dev->lock);
+
+ if (ret)
+ usb_autopm_put_interface(stream->dev->intf);
+
+ return ret;
+}
+
+static void uvc_pm_put(struct uvc_streaming *stream)
+{
+ mutex_lock(&stream->dev->lock);
+ if (WARN_ON(!stream->dev->users)) {
+ mutex_unlock(&stream->dev->lock);
+ return;
+ }
+ stream->dev->users--;
+ if (!stream->dev->users)
+ uvc_status_stop(stream->dev);
+ mutex_unlock(&stream->dev->lock);
+
+ usb_autopm_put_interface(stream->dev->intf);
+}
+
/* ------------------------------------------------------------------------
* UVC ioctls
*/
@@ -245,6 +289,9 @@ static int uvc_v4l2_try_format(struct uvc_streaming *stream,
* developers test their webcams with the Linux driver as well as with
* the Windows driver).
*/
+ ret = uvc_pm_get(stream);
+ if (ret)
+ goto done;
mutex_lock(&stream->mutex);
if (stream->dev->quirks & UVC_QUIRK_PROBE_EXTRAFIELDS)
probe->dwMaxVideoFrameSize =
@@ -253,6 +300,7 @@ static int uvc_v4l2_try_format(struct uvc_streaming *stream,
/* Probe the device. */
ret = uvc_probe_video(stream, probe);
mutex_unlock(&stream->mutex);
+ uvc_pm_put(stream);
if (ret < 0)
goto done;
@@ -464,7 +512,13 @@ static int uvc_v4l2_set_streamparm(struct uvc_streaming *stream,
}
/* Probe the device with the new settings. */
+ ret = uvc_pm_get(stream);
+ if (ret) {
+ mutex_unlock(&stream->mutex);
+ return ret;
+ }
ret = uvc_probe_video(stream, &probe);
+ uvc_pm_put(stream);
if (ret < 0) {
mutex_unlock(&stream->mutex);
return ret;
@@ -555,36 +609,24 @@ static int uvc_v4l2_open(struct file *file)
{
struct uvc_streaming *stream;
struct uvc_fh *handle;
- int ret = 0;
stream = video_drvdata(file);
uvc_dbg(stream->dev, CALLS, "%s\n", __func__);
- ret = usb_autopm_get_interface(stream->dev->intf);
- if (ret < 0)
- return ret;
-
/* Create the device handle. */
handle = kzalloc(sizeof(*handle), GFP_KERNEL);
- if (handle == NULL) {
- usb_autopm_put_interface(stream->dev->intf);
+ if (!handle)
return -ENOMEM;
- }
- mutex_lock(&stream->dev->lock);
- if (stream->dev->users == 0) {
- ret = uvc_status_start(stream->dev, GFP_KERNEL);
- if (ret < 0) {
- mutex_unlock(&stream->dev->lock);
- usb_autopm_put_interface(stream->dev->intf);
- kfree(handle);
- return ret;
- }
+ /*
+ * If the uvc evdev exists we cannot suspend when the device
+ * is idle. Otherwise we will miss button actions.
+ */
+ if (stream->dev->input && uvc_pm_get(stream)) {
+ kfree(handle);
+ return -ENODEV;
}
- stream->dev->users++;
- mutex_unlock(&stream->dev->lock);
-
v4l2_fh_init(&handle->vfh, &stream->vdev);
v4l2_fh_add(&handle->vfh);
handle->chain = stream->chain;
@@ -606,6 +648,12 @@ static int uvc_v4l2_release(struct file *file)
if (uvc_has_privileges(handle))
uvc_queue_release(&stream->queue);
+ if (handle->is_streaming)
+ uvc_pm_put(stream);
+
+ if (stream->dev->input)
+ uvc_pm_put(stream);
+
/* Release the file handle. */
uvc_dismiss_privileges(handle);
v4l2_fh_del(&handle->vfh);
@@ -613,12 +661,6 @@ static int uvc_v4l2_release(struct file *file)
kfree(handle);
file->private_data = NULL;
- mutex_lock(&stream->dev->lock);
- if (--stream->dev->users == 0)
- uvc_status_stop(stream->dev);
- mutex_unlock(&stream->dev->lock);
-
- usb_autopm_put_interface(stream->dev->intf);
return 0;
}
@@ -845,9 +887,17 @@ static int uvc_ioctl_streamon(struct file *file, void *fh,
if (handle->is_streaming)
goto unlock;
+
+ ret = uvc_pm_get(stream);
+ if (ret)
+ goto unlock;
+
ret = uvc_queue_streamon(&stream->queue, type);
handle->is_streaming = !ret;
+ if (!handle->is_streaming)
+ uvc_pm_put(stream);
+
unlock:
mutex_unlock(&stream->mutex);
@@ -871,6 +921,9 @@ static int uvc_ioctl_streamoff(struct file *file, void *fh,
ret = uvc_queue_streamoff(&stream->queue, type);
handle->is_streaming = !!ret;
+ if (!handle->is_streaming)
+ uvc_pm_put(stream);
+
unlock:
mutex_unlock(&stream->mutex);
@@ -922,6 +975,7 @@ static int uvc_ioctl_g_input(struct file *file, void *fh, unsigned int *input)
{
struct uvc_fh *handle = fh;
struct uvc_video_chain *chain = handle->chain;
+ struct uvc_streaming *stream = handle->stream;
u8 *buf;
int ret;
@@ -935,9 +989,16 @@ static int uvc_ioctl_g_input(struct file *file, void *fh, unsigned int *input)
if (!buf)
return -ENOMEM;
+ ret = uvc_pm_get(stream);
+ if (ret) {
+ kfree(buf);
+ return ret;
+ }
+
ret = uvc_query_ctrl(chain->dev, UVC_GET_CUR, chain->selector->id,
chain->dev->intfnum, UVC_SU_INPUT_SELECT_CONTROL,
buf, 1);
+ uvc_pm_put(stream);
if (!ret)
*input = *buf - 1;
@@ -950,6 +1011,7 @@ static int uvc_ioctl_s_input(struct file *file, void *fh, unsigned int input)
{
struct uvc_fh *handle = fh;
struct uvc_video_chain *chain = handle->chain;
+ struct uvc_streaming *stream = handle->stream;
u8 *buf;
int ret;
@@ -971,10 +1033,17 @@ static int uvc_ioctl_s_input(struct file *file, void *fh, unsigned int input)
if (!buf)
return -ENOMEM;
+ ret = uvc_pm_get(stream);
+ if (ret) {
+ kfree(buf);
+ return ret;
+ }
+
*buf = input + 1;
ret = uvc_query_ctrl(chain->dev, UVC_SET_CUR, chain->selector->id,
chain->dev->intfnum, UVC_SU_INPUT_SELECT_CONTROL,
buf, 1);
+ uvc_pm_put(stream);
kfree(buf);
return ret;
@@ -985,8 +1054,15 @@ static int uvc_ioctl_queryctrl(struct file *file, void *fh,
{
struct uvc_fh *handle = fh;
struct uvc_video_chain *chain = handle->chain;
+ struct uvc_streaming *stream = handle->stream;
+ int ret;
- return uvc_query_v4l2_ctrl(chain, qc);
+ ret = uvc_pm_get(stream);
+ if (ret)
+ return ret;
+ ret = uvc_query_v4l2_ctrl(chain, qc);
+ uvc_pm_put(stream);
+ return ret;
}
static int uvc_ioctl_query_ext_ctrl(struct file *file, void *fh,
@@ -994,10 +1070,15 @@ static int uvc_ioctl_query_ext_ctrl(struct file *file, void *fh,
{
struct uvc_fh *handle = fh;
struct uvc_video_chain *chain = handle->chain;
+ struct uvc_streaming *stream = handle->stream;
struct v4l2_queryctrl qc = { qec->id };
int ret;
+ ret = uvc_pm_get(stream);
+ if (ret)
+ return ret;
ret = uvc_query_v4l2_ctrl(chain, &qc);
+ uvc_pm_put(stream);
if (ret)
return ret;
@@ -1043,6 +1124,7 @@ static int uvc_ioctl_g_ext_ctrls(struct file *file, void *fh,
{
struct uvc_fh *handle = fh;
struct uvc_video_chain *chain = handle->chain;
+ struct uvc_streaming *stream = handle->stream;
struct v4l2_ext_control *ctrl = ctrls->controls;
unsigned int i;
int ret;
@@ -1067,22 +1149,30 @@ static int uvc_ioctl_g_ext_ctrls(struct file *file, void *fh,
return 0;
}
+ ret = uvc_pm_get(stream);
+ if (ret)
+ return ret;
ret = uvc_ctrl_begin(chain);
- if (ret < 0)
+ if (ret < 0) {
+ uvc_pm_put(stream);
return ret;
+ }
for (i = 0; i < ctrls->count; ++ctrl, ++i) {
ret = uvc_ctrl_get(chain, ctrl);
if (ret < 0) {
uvc_ctrl_rollback(handle);
ctrls->error_idx = i;
- return ret;
+ goto done;
}
}
ctrls->error_idx = 0;
- return uvc_ctrl_rollback(handle);
+ ret = uvc_ctrl_rollback(handle);
+done:
+ uvc_pm_put(stream);
+ return ret;
}
static int uvc_ioctl_s_try_ext_ctrls(struct uvc_fh *handle,
@@ -1091,6 +1181,7 @@ static int uvc_ioctl_s_try_ext_ctrls(struct uvc_fh *handle,
{
struct v4l2_ext_control *ctrl = ctrls->controls;
struct uvc_video_chain *chain = handle->chain;
+ struct uvc_streaming *stream = handle->stream;
unsigned int i;
int ret;
@@ -1098,9 +1189,15 @@ static int uvc_ioctl_s_try_ext_ctrls(struct uvc_fh *handle,
if (ret < 0)
return ret;
+ ret = uvc_pm_get(stream);
+ if (ret)
+ return ret;
+
ret = uvc_ctrl_begin(chain);
- if (ret < 0)
+ if (ret < 0) {
+ uvc_pm_put(stream);
return ret;
+ }
for (i = 0; i < ctrls->count; ++ctrl, ++i) {
ret = uvc_ctrl_set(handle, ctrl);
@@ -1108,16 +1205,20 @@ static int uvc_ioctl_s_try_ext_ctrls(struct uvc_fh *handle,
uvc_ctrl_rollback(handle);
ctrls->error_idx = ioctl == VIDIOC_S_EXT_CTRLS ?
ctrls->count : i;
- return ret;
+ goto done;
}
}
ctrls->error_idx = 0;
if (ioctl == VIDIOC_S_EXT_CTRLS)
- return uvc_ctrl_commit(handle, ctrls);
+ ret = uvc_ctrl_commit(handle, ctrls);
else
- return uvc_ctrl_rollback(handle);
+ ret = uvc_ctrl_rollback(handle);
+
+done:
+ uvc_pm_put(stream);
+ return ret;
}
static int uvc_ioctl_s_ext_ctrls(struct file *file, void *fh,
@@ -1141,8 +1242,16 @@ static int uvc_ioctl_querymenu(struct file *file, void *fh,
{
struct uvc_fh *handle = fh;
struct uvc_video_chain *chain = handle->chain;
+ struct uvc_streaming *stream = handle->stream;
+ int ret;
+
+ ret = uvc_pm_get(stream);
+ if (ret)
+ return ret;
+ ret = uvc_query_v4l2_menu(chain, qm);
+ uvc_pm_put(stream);
- return uvc_query_v4l2_menu(chain, qm);
+ return ret;
}
static int uvc_ioctl_g_selection(struct file *file, void *fh,
--
2.35.0.263.gb82422642f-goog
Powered by blists - more mailing lists