Hi Sakari,
Sakari Ailus wrote:
> Hi Mauro,
>
> The latest event patchset is available in my Gitorious tree now. The
> file handles documentation patch changed due to unrelated changes in
> Documentation/video4linux/v4l2-framework.txt. There are no other changes
> compared to the patches sent to the list earlier.
>
> Please pull.
>
> The following changes since commit 9178a7c062ff0c43e95d826419f9e9454c52ef15:
> Mauro Carvalho Chehab (1):
> V4L/DVB: Fix bad whitespacing
>
> are available in the git repository at:
>
> git://gitorious.org/omap3camera/mainline.git v4l-dvb-event
>
> Sakari Ailus (6):
> V4L: File handles
The idea of having a common file handle at the V4L2 core is interesting, but
I see some troubles on it. As you said on this changeset's comment:
V4L/DVB: V4L: File handles
This patch adds a list of v4l2_fh structures to every video_device.
It allows using file handle related information in V4L2. The event interface
is one example of such use.
Video device drivers should use the v4l2_fh pointer as their
file->private_data.
You're saying that the drivers should use struct v4l2_fh, but there
aren't any patches on your series enforcing this change.
Also, you're defining it as just:
+struct v4l2_fh {
+ struct list_head list;
+ struct video_device *vdev;
+};
while other drivers need something much more complex. For example, saa7134
defines the file handler struct used on file-private_data as:
struct saa7134_fh {
struct saa7134_dev *dev;
unsigned int radio;
enum v4l2_buf_type type;
unsigned int resources;
enum v4l2_priority prio;
/* video overlay */
struct v4l2_window win;
struct v4l2_clip clips[8];
unsigned int nclips;
/* video capture */
struct saa7134_format *fmt;
unsigned int width,height;
struct videobuf_queue cap;
struct saa7134_pgtable pt_cap;
/* vbi capture */
struct videobuf_queue vbi;
struct saa7134_pgtable pt_vbi;
};
Even the simplest driver we have (vivi) require more than just
the video device:
struct vivi_fh {
struct vivi_dev *dev;
/* video capture */
struct vivi_fmt *fmt;
unsigned int width, height;
struct videobuf_queue vb_vidq;
enum v4l2_buf_type type;
unsigned char bars[8][3];
int input; /* Input Number on bars */
};
So, it is not clear for me how to convert any of the existing
drivers to fit on your proposal.
Also, the better is if you could provide us a patchset with the needed
conversion. It is interesting if you could add some notes there about why
this change is needed.
Cheers,
Mauro
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