Re: [PATCH v2 00/10] Support getting default values from any control

From: Hans Verkuil
Date: Fri Sep 04 2015 - 07:02:15 EST


This patch series looks good. I'll drop the saa7164 patches since I made a
patch series converting it to the control framework. Once Steve gives me the
Ack for that I can merge that series.

All I need to merge your series (minus the saa7164 patches) is the Ack from
Laurent for the uvc patch.

Regards,

Hans

On 08/21/2015 03:19 PM, Ricardo Ribalda Delgado wrote:
> Integer controls provide a way to get their default/initial value, but
> any other control (p_u32, p_u8.....) provide no other way to get the
> initial value than unloading the module and loading it back.
>
> *What is the actual problem?
> I have a custom control with WIDTH integer values. Every value
> represents the calibrated FPN (fixed pattern noise) correction value for that
> column
> -Application A changes the FPN correction value
> -Application B wants to restore the calibrated value but it cant :(
>
> *What is the proposed solution?
>
> (Kudos to Hans Verkuil!!!)
>
> The key change is in struct v4l2_ext_controls where the __u32 ctrl_class field
> is changed to:
>
> union {
> __u32 ctrl_class;
> __u32 which;
> };
>
> And two new defines are added:
>
> #define V4L2_CTRL_WHICH_CUR_VAL 0
> #define V4L2_CTRL_WHICH_DEF_VAL 0x0f000000
>
> The 'which' field tells you which controls are get/set/tried.
>
> V4L2_CTRL_WHICH_CUR_VAL: the current value of the controls
> V4L2_CTRL_WHICH_DEF_VAL: the default value of the controls
> V4L2_CTRL_CLASS_*: the current value of the controls belonging to the specified class.
> Note: this is deprecated usage and is only there for backwards compatibility.
> Which is also why I don't think there is a need to add V4L2_CTRL_WHICH_
> aliases for these defines.
>
>
> I have posted a copy of my working tree to
>
> https://github.com/ribalda/linux/tree/which_def_v2
>
> Changelog v2:
>
> Suggested by Hans Verkuil <hverkuil@xxxxxxxxx>
>
> Replace ctrls_class with which on all the codebase
> Changes in Documentation
> (Thanks!)
>
> Ricardo Ribalda Delgado (10):
> videodev2.h: Fix typo in comment
> videodev2.h: Extend struct v4l2_ext_controls
> media/v4l2-compat-ioctl32: Simple stylechecks
> media/core: Replace ctrl_class with which
> media/v4l2-core: struct struct v4l2_ext_controls param which
> usb/uvc: Support for V4L2_CTRL_WHICH_DEF_VAL
> media/usb/pvrusb2: Support for V4L2_CTRL_WHICH_DEF_VAL
> media/pci/saa7164-encoder Support for V4L2_CTRL_WHICH_DEF_VAL
> media/pci/saa7164-vbi Support for V4L2_CTRL_WHICH_DEF_VAL
> Docbook: media: Document changes on struct v4l2_ext_controls
>
> Documentation/DocBook/media/v4l/v4l2.xml | 9 ++++
> .../DocBook/media/v4l/vidioc-g-ext-ctrls.xml | 28 ++++++++--
> drivers/media/pci/saa7164/saa7164-encoder.c | 59 ++++++++++++---------
> drivers/media/pci/saa7164/saa7164-vbi.c | 61 +++++++++++++---------
> drivers/media/platform/s5p-mfc/s5p_mfc_dec.c | 2 +-
> drivers/media/platform/s5p-mfc/s5p_mfc_enc.c | 2 +-
> drivers/media/usb/pvrusb2/pvrusb2-v4l2.c | 17 +++++-
> drivers/media/usb/uvc/uvc_v4l2.c | 14 ++++-
> drivers/media/v4l2-core/v4l2-compat-ioctl32.c | 17 +++---
> drivers/media/v4l2-core/v4l2-ctrls.c | 54 +++++++++++++------
> drivers/media/v4l2-core/v4l2-ioctl.c | 14 ++---
> include/uapi/linux/videodev2.h | 14 ++++-
> 12 files changed, 200 insertions(+), 91 deletions(-)
>

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