Some comments for future improvements:
On 03/24/2014 08:33 PM, Frank Schäfer wrote:
> Signed-off-by: Frank Schäfer <fschaefer.oss@xxxxxxxxxxxxxx>
> ---
> drivers/media/usb/em28xx/em28xx-camera.c | 4 +-
> drivers/media/usb/em28xx/em28xx-video.c | 160 +++++++++++++++++++++----------
> drivers/media/usb/em28xx/em28xx.h | 8 +-
> 3 files changed, 116 insertions(+), 56 deletions(-)
>
> diff --git a/drivers/media/usb/em28xx/em28xx-camera.c b/drivers/media/usb/em28xx/em28xx-camera.c
> index 505e050..daebef3 100644
> --- a/drivers/media/usb/em28xx/em28xx-camera.c
> +++ b/drivers/media/usb/em28xx/em28xx-camera.c
> @@ -365,7 +365,7 @@ int em28xx_init_camera(struct em28xx *dev)
> dev->sensor_xtal = 4300000;
> pdata.xtal = dev->sensor_xtal;
> if (NULL ==
> - v4l2_i2c_new_subdev_board(&dev->v4l2_dev, adap,
> + v4l2_i2c_new_subdev_board(&dev->v4l2->v4l2_dev, adap,
> &mt9v011_info, NULL)) {
> ret = -ENODEV;
> break;
> @@ -422,7 +422,7 @@ int em28xx_init_camera(struct em28xx *dev)
> dev->sensor_yres = 480;
>
> subdev =
> - v4l2_i2c_new_subdev_board(&dev->v4l2_dev, adap,
> + v4l2_i2c_new_subdev_board(&dev->v4l2->v4l2_dev, adap,
> &ov2640_info, NULL);
> if (NULL == subdev) {
> ret = -ENODEV;
> diff --git a/drivers/media/usb/em28xx/em28xx-video.c b/drivers/media/usb/em28xx/em28xx-video.c
> index 45ad471..89947db 100644
> --- a/drivers/media/usb/em28xx/em28xx-video.c
> +++ b/drivers/media/usb/em28xx/em28xx-video.c
> @@ -189,10 +189,11 @@ static int em28xx_vbi_supported(struct em28xx *dev)
> */
> static void em28xx_wake_i2c(struct em28xx *dev)
> {
> - v4l2_device_call_all(&dev->v4l2_dev, 0, core, reset, 0);
> - v4l2_device_call_all(&dev->v4l2_dev, 0, video, s_routing,
> + struct v4l2_device *v4l2_dev = &dev->v4l2->v4l2_dev;
> + v4l2_device_call_all(v4l2_dev, 0, core, reset, 0);
> + v4l2_device_call_all(v4l2_dev, 0, video, s_routing,
> INPUT(dev->ctl_input)->vmux, 0, 0);
> - v4l2_device_call_all(&dev->v4l2_dev, 0, video, s_stream, 0);
> + v4l2_device_call_all(v4l2_dev, 0, video, s_stream, 0);
> }
>
> static int em28xx_colorlevels_set_default(struct em28xx *dev)
> @@ -952,7 +953,8 @@ int em28xx_start_analog_streaming(struct vb2_queue *vq, unsigned int count)
> f.type = V4L2_TUNER_RADIO;
> else
> f.type = V4L2_TUNER_ANALOG_TV;
> - v4l2_device_call_all(&dev->v4l2_dev, 0, tuner, s_frequency, &f);
> + v4l2_device_call_all(&dev->v4l2->v4l2_dev,
> + 0, tuner, s_frequency, &f);
> }
>
> dev->streaming_users++;
> @@ -1083,6 +1085,7 @@ static int em28xx_vb2_setup(struct em28xx *dev)
>
> static void video_mux(struct em28xx *dev, int index)
> {
> + struct v4l2_device *v4l2_dev = &dev->v4l2->v4l2_dev;
> dev->ctl_input = index;
> dev->ctl_ainput = INPUT(index)->amux;
> dev->ctl_aoutput = INPUT(index)->aout;
> @@ -1090,21 +1093,21 @@ static void video_mux(struct em28xx *dev, int index)
> if (!dev->ctl_aoutput)
> dev->ctl_aoutput = EM28XX_AOUT_MASTER;
>
> - v4l2_device_call_all(&dev->v4l2_dev, 0, video, s_routing,
> + v4l2_device_call_all(v4l2_dev, 0, video, s_routing,
> INPUT(index)->vmux, 0, 0);
>
> if (dev->board.has_msp34xx) {
> if (dev->i2s_speed) {
> - v4l2_device_call_all(&dev->v4l2_dev, 0, audio,
> + v4l2_device_call_all(v4l2_dev, 0, audio,
> s_i2s_clock_freq, dev->i2s_speed);
> }
> /* Note: this is msp3400 specific */
> - v4l2_device_call_all(&dev->v4l2_dev, 0, audio, s_routing,
> + v4l2_device_call_all(v4l2_dev, 0, audio, s_routing,
> dev->ctl_ainput, MSP_OUTPUT(MSP_SC_IN_DSP_SCART1), 0);
> }
>
> if (dev->board.adecoder != EM28XX_NOADECODER) {
> - v4l2_device_call_all(&dev->v4l2_dev, 0, audio, s_routing,
> + v4l2_device_call_all(v4l2_dev, 0, audio, s_routing,
> dev->ctl_ainput, dev->ctl_aoutput, 0);
> }
>
> @@ -1344,7 +1347,7 @@ static int vidioc_querystd(struct file *file, void *priv, v4l2_std_id *norm)
> struct em28xx_fh *fh = priv;
> struct em28xx *dev = fh->dev;
>
> - v4l2_device_call_all(&dev->v4l2_dev, 0, video, querystd, norm);
> + v4l2_device_call_all(&dev->v4l2->v4l2_dev, 0, video, querystd, norm);
>
> return 0;
> }
> @@ -1374,7 +1377,7 @@ static int vidioc_s_std(struct file *file, void *priv, v4l2_std_id norm)
> size_to_scale(dev, dev->width, dev->height, &dev->hscale, &dev->vscale);
>
> em28xx_resolution_set(dev);
> - v4l2_device_call_all(&dev->v4l2_dev, 0, core, s_std, dev->norm);
> + v4l2_device_call_all(&dev->v4l2->v4l2_dev, 0, core, s_std, dev->norm);
>
> return 0;
> }
> @@ -1388,7 +1391,7 @@ static int vidioc_g_parm(struct file *file, void *priv,
>
> p->parm.capture.readbuffers = EM28XX_MIN_BUF;
> if (dev->board.is_webcam)
> - rc = v4l2_device_call_until_err(&dev->v4l2_dev, 0,
> + rc = v4l2_device_call_until_err(&dev->v4l2->v4l2_dev, 0,
> video, g_parm, p);
> else
> v4l2_video_std_frame_period(dev->norm,
> @@ -1404,7 +1407,8 @@ static int vidioc_s_parm(struct file *file, void *priv,
> struct em28xx *dev = fh->dev;
>
> p->parm.capture.readbuffers = EM28XX_MIN_BUF;
> - return v4l2_device_call_until_err(&dev->v4l2_dev, 0, video, s_parm, p);
> + return v4l2_device_call_until_err(&dev->v4l2->v4l2_dev,
> + 0, video, s_parm, p);
> }
>
> static const char *iname[] = {
> @@ -1543,7 +1547,7 @@ static int vidioc_g_tuner(struct file *file, void *priv,
>
> strcpy(t->name, "Tuner");
>
> - v4l2_device_call_all(&dev->v4l2_dev, 0, tuner, g_tuner, t);
> + v4l2_device_call_all(&dev->v4l2->v4l2_dev, 0, tuner, g_tuner, t);
> return 0;
> }
>
> @@ -1556,7 +1560,7 @@ static int vidioc_s_tuner(struct file *file, void *priv,
> if (0 != t->index)
> return -EINVAL;
>
> - v4l2_device_call_all(&dev->v4l2_dev, 0, tuner, s_tuner, t);
> + v4l2_device_call_all(&dev->v4l2->v4l2_dev, 0, tuner, s_tuner, t);
> return 0;
> }
>
> @@ -1576,15 +1580,16 @@ static int vidioc_g_frequency(struct file *file, void *priv,
> static int vidioc_s_frequency(struct file *file, void *priv,
> const struct v4l2_frequency *f)
> {
> - struct v4l2_frequency new_freq = *f;
> - struct em28xx_fh *fh = priv;
> - struct em28xx *dev = fh->dev;
> + struct v4l2_frequency new_freq = *f;
> + struct em28xx_fh *fh = priv;
> + struct em28xx *dev = fh->dev;
> + struct em28xx_v4l2 *v4l2 = dev->v4l2;
>
> if (0 != f->tuner)
> return -EINVAL;
>
> - v4l2_device_call_all(&dev->v4l2_dev, 0, tuner, s_frequency, f);
> - v4l2_device_call_all(&dev->v4l2_dev, 0, tuner, g_frequency, &new_freq);
> + v4l2_device_call_all(&v4l2->v4l2_dev, 0, tuner, s_frequency, f);
> + v4l2_device_call_all(&v4l2->v4l2_dev, 0, tuner, g_frequency, &new_freq);
> dev->ctl_freq = new_freq.frequency;
>
> return 0;
> @@ -1602,7 +1607,8 @@ static int vidioc_g_chip_info(struct file *file, void *priv,
> if (chip->match.addr == 1)
> strlcpy(chip->name, "ac97", sizeof(chip->name));
> else
> - strlcpy(chip->name, dev->v4l2_dev.name, sizeof(chip->name));
> + strlcpy(chip->name,
> + dev->v4l2->v4l2_dev.name, sizeof(chip->name));
> return 0;
> }
>
> @@ -1814,7 +1820,7 @@ static int radio_g_tuner(struct file *file, void *priv,
>
> strcpy(t->name, "Radio");
>
> - v4l2_device_call_all(&dev->v4l2_dev, 0, tuner, g_tuner, t);
> + v4l2_device_call_all(&dev->v4l2->v4l2_dev, 0, tuner, g_tuner, t);
>
> return 0;
> }
> @@ -1827,12 +1833,26 @@ static int radio_s_tuner(struct file *file, void *priv,
> if (0 != t->index)
> return -EINVAL;
>
> - v4l2_device_call_all(&dev->v4l2_dev, 0, tuner, s_tuner, t);
> + v4l2_device_call_all(&dev->v4l2->v4l2_dev, 0, tuner, s_tuner, t);
>
> return 0;
> }
>
> /*
> + * em28xx_free_v4l2() - Free struct em28xx_v4l2
> + *
> + * @ref: struct kref for struct em28xx_v4l2
> + *
> + * Called when all users of struct em28xx_v4l2 are gone
> + */
> +void em28xx_free_v4l2(struct kref *ref)
> +{
> + struct em28xx_v4l2 *v4l2 = container_of(ref, struct em28xx_v4l2, ref);
> +
> + kfree(v4l2);
> +}
> +
> +/*
> * em28xx_v4l2_open()
> * inits the device and starts isoc transfer
> */
> @@ -1840,6 +1860,7 @@ static int em28xx_v4l2_open(struct file *filp)
> {
> struct video_device *vdev = video_devdata(filp);
> struct em28xx *dev = video_drvdata(filp);
> + struct em28xx_v4l2 *v4l2 = dev->v4l2;
> enum v4l2_buf_type fh_type = 0;
> struct em28xx_fh *fh;
>
> @@ -1888,10 +1909,11 @@ static int em28xx_v4l2_open(struct file *filp)
>
> if (vdev->vfl_type == VFL_TYPE_RADIO) {
> em28xx_videodbg("video_open: setting radio device\n");
> - v4l2_device_call_all(&dev->v4l2_dev, 0, tuner, s_radio);
> + v4l2_device_call_all(&v4l2->v4l2_dev, 0, tuner, s_radio);
> }
>
> kref_get(&dev->ref);
> + kref_get(&v4l2->ref);
I never like these kref things. Especially for usb devices I strongly recommend
using the release() callback from v4l2_device instead: this callback will only
be called once all references to video_device nodes have been closed. In other
words, only once all filehandles to /dev/videoX (and radio, vbi etc) are closed
will the release callback be called.
As such it is a perfect place to put the final cleanup, and there is no more need
to mess around with krefs.
> dev->users++;
The same for these user counters. You can use v4l2_fh_is_singular_file() to check
if the file open is the first file. However, this function assumes that v4l2_fh_add
has been called first.
So for this driver it might be easier if we add a v4l2_fh_is_empty() to v4l2-fh.c
so we can call this before v4l2_fh_add.
For that matter, you can almost certainly remove struct em28xx_fh altogether.
The type field of that struct can be determined by vdev->vfl_type and 'dev' can be
obtained via video_get_drvdata().
Regards,
Hans
>
> mutex_unlock(&dev->lock);
--
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