Re: [RFCv1 PATCH 04/32] v4l2-ioctl.c: v4l2-ioctl: add debug and callback/offset functionality.
Hi Hans,
Thanks for the patch.
On Sunday 10 June 2012 12:25:26 Hans Verkuil wrote:
> From: Hans Verkuil <hans.verkuil@xxxxxxxxx>
>
> Add the necessary plumbing to make it possible to replace the switch by a
> table driven implementation.
>
> Signed-off-by: Hans Verkuil <hans.verkuil@xxxxxxxxx>
> ---
> drivers/media/video/v4l2-ioctl.c | 91
> ++++++++++++++++++++++++++++++++------ 1 file changed, 78 insertions(+), 13
> deletions(-)
>
> diff --git a/drivers/media/video/v4l2-ioctl.c
> b/drivers/media/video/v4l2-ioctl.c index a9602db..a4115ce 100644
> --- a/drivers/media/video/v4l2-ioctl.c
> +++ b/drivers/media/video/v4l2-ioctl.c
> @@ -396,12 +396,22 @@ struct v4l2_ioctl_info {
> unsigned int ioctl;
> u32 flags;
> const char * const name;
> + union {
> + u32 offset;
> + int (*func)(const struct v4l2_ioctl_ops *ops,
> + struct file *file, void *fh, void *p);
> + };
> + void (*debug)(const void *arg);
> };
>
> /* This control needs a priority check */
> #define INFO_FL_PRIO (1 << 0)
> /* This control can be valid if the filehandle passes a control handler. */
> #define INFO_FL_CTRL (1 << 1)
> +/* This is a standard ioctl, no need for special code */
> +#define INFO_FL_STD (1 << 2)
> +/* This is ioctl has its own function */
> +#define INFO_FL_FUNC (1 << 3)
> /* Zero struct from after the field to the end */
> #define INFO_FL_CLEAR(v4l2_struct, field) \
> ((offsetof(struct v4l2_struct, field) + \
> @@ -414,6 +424,24 @@ struct v4l2_ioctl_info {
> .name = #_ioctl, \
> }
>
> +#define IOCTL_INFO_STD(_ioctl, _vidioc, _debug, _flags) \
> + [_IOC_NR(_ioctl)] = { \
> + .ioctl = _ioctl, \
> + .flags = _flags | INFO_FL_STD, \
> + .name = #_ioctl, \
> + .offset = offsetof(struct v4l2_ioctl_ops, _vidioc), \
> + .debug = _debug, \
> + }
> +
> +#define IOCTL_INFO_FNC(_ioctl, _func, _debug, _flags) \
> + [_IOC_NR(_ioctl)] = { \
> + .ioctl = _ioctl, \
> + .flags = _flags | INFO_FL_FUNC, \
> + .name = #_ioctl, \
> + .func = _func, \
> + .debug = _debug, \
> + }
> +
> static struct v4l2_ioctl_info v4l2_ioctls[] = {
> IOCTL_INFO(VIDIOC_QUERYCAP, 0),
> IOCTL_INFO(VIDIOC_ENUM_FMT, INFO_FL_CLEAR(v4l2_fmtdesc, type)),
> @@ -512,7 +540,7 @@ bool v4l2_is_known_ioctl(unsigned int cmd)
> external ioctl messages as well as internal V4L ioctl */
> void v4l_printk_ioctl(unsigned int cmd)
> {
> - char *dir, *type;
> + const char *dir, *type;
>
> switch (_IOC_TYPE(cmd)) {
> case 'd':
> @@ -523,10 +551,11 @@ void v4l_printk_ioctl(unsigned int cmd)
> type = "v4l2";
> break;
> }
> - printk("%s", v4l2_ioctls[_IOC_NR(cmd)].name);
> + pr_cont("%s", v4l2_ioctls[_IOC_NR(cmd)].name);
> return;
> default:
> type = "unknown";
> + break;
> }
>
> switch (_IOC_DIR(cmd)) {
> @@ -536,7 +565,7 @@ void v4l_printk_ioctl(unsigned int cmd)
> case _IOC_READ | _IOC_WRITE: dir = "rw"; break;
> default: dir = "*ERR*"; break;
> }
> - printk("%s ioctl '%c', dir=%s, #%d (0x%08x)",
> + pr_cont("%s ioctl '%c', dir=%s, #%d (0x%08x)",
> type, _IOC_TYPE(cmd), dir, _IOC_NR(cmd), cmd);
> }
> EXPORT_SYMBOL(v4l_printk_ioctl);
> @@ -546,6 +575,9 @@ static long __video_do_ioctl(struct file *file,
> {
> struct video_device *vfd = video_devdata(file);
> const struct v4l2_ioctl_ops *ops = vfd->ioctl_ops;
> + bool write_only = false;
> + struct v4l2_ioctl_info default_info;
> + const struct v4l2_ioctl_info *info;
> void *fh = file->private_data;
> struct v4l2_fh *vfh = NULL;
> int use_fh_prio = 0;
> @@ -563,23 +595,40 @@ static long __video_do_ioctl(struct file *file,
> }
>
> if (v4l2_is_known_ioctl(cmd)) {
> - struct v4l2_ioctl_info *info = &v4l2_ioctls[_IOC_NR(cmd)];
> + info = &v4l2_ioctls[_IOC_NR(cmd)];
>
> if (!test_bit(_IOC_NR(cmd), vfd->valid_ioctls) &&
> !((info->flags & INFO_FL_CTRL) && vfh && vfh->ctrl_handler))
> - return -ENOTTY;
> + goto error;
>
> if (use_fh_prio && (info->flags & INFO_FL_PRIO)) {
> ret = v4l2_prio_check(vfd->prio, vfh->prio);
> if (ret)
> - return ret;
> + goto error;
> }
> + } else {
> + default_info.ioctl = cmd;
> + default_info.flags = 0;
> + default_info.debug = NULL;
> + info = &default_info;
> }
>
> - if ((vfd->debug & V4L2_DEBUG_IOCTL) &&
> - !(vfd->debug & V4L2_DEBUG_IOCTL_ARG)) {
> + write_only = _IOC_DIR(cmd) == _IOC_WRITE;
> + if (info->debug && write_only && vfd->debug > V4L2_DEBUG_IOCTL) {
> v4l_print_ioctl(vfd->name, cmd);
> - printk(KERN_CONT "\n");
> + pr_cont(": ");
> + info->debug(arg);
> + }
Shouldn't you print the ioctl name and information even if info->debug is NULL
?
> + if (info->flags & INFO_FL_STD) {
> + typedef int (*vidioc_op)(struct file *file, void *fh, void *p);
> + const void *p = vfd->ioctl_ops;
> + const vidioc_op *vidioc = p + info->offset;
> +
> + ret = (*vidioc)(file, fh, arg);
> + goto error;
> + } else if (info->flags & INFO_FL_FUNC) {
> + ret = info->func(ops, file, fh, arg);
> + goto error;
> }
>
> switch (cmd) {
> @@ -2100,10 +2149,26 @@ static long __video_do_ioctl(struct file *file,
> break;
> } /* switch */
>
> - if (vfd->debug & V4L2_DEBUG_IOCTL_ARG) {
> - if (ret < 0) {
> - v4l_print_ioctl(vfd->name, cmd);
> - printk(KERN_CONT " error %ld\n", ret);
> +error:
This isn't an error, is it ? I'd call it done instead.
> + if (vfd->debug) {
> + if (write_only && vfd->debug > V4L2_DEBUG_IOCTL) {
vfd->debug is a bitmask (or at least is documented as being a bitmask in
include/media/v4l2-ioctl.h).
> + if (ret)
Shouldn't you test for < 0 instead ? Driver-specific ioctls might return a > 0
value in case of success.
> + pr_info("%s: error %ld\n",
> + video_device_node_name(vfd), ret);
> + return ret;
> + }
> + v4l_print_ioctl(vfd->name, cmd);
> + if (ret)
> + pr_cont(": error %ld\n", ret);
> + else if (vfd->debug == V4L2_DEBUG_IOCTL)
> + pr_cont("\n");
> + else if (!info->debug)
> + return ret;
> + else if (_IOC_DIR(cmd) == _IOC_NONE)
> + info->debug(arg);
> + else {
> + pr_cont(": ");
> + info->debug(arg);
> }
Ouch. What are you trying to do here ? Can't we simplify debug messages ?
> }
--
Regards,
Laurent Pinchart
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