[libcamera-devel] [PATCH 20/25] media: ov5647: Program mode only if it has changed
Dafna Hirschfeld
dafna.hirschfeld at collabora.com
Tue Jun 30 11:32:12 CEST 2020
On 30.06.20 09:43, Jacopo Mondi wrote:
> Hi Dafna,
>
> On Mon, Jun 29, 2020 at 07:48:16PM +0200, Dafna Hirschfeld wrote:
>>
>>
>> On 23.06.20 18:55, Jacopo Mondi wrote:
>>> Store in the driver structure a pointer to the currently applied mode
>>> and program a new one at s_stream(1) time only if it has changed.
>>
>> Hi,
>> I think this can be more readably implemented with a 'is_streaming' boolean
>> field.
>
> How would you like to use an 'is_streaming' flag to decide if the
> sensor mode has to be updated ?
since 'current_mode' is set to NULL upon `ov5647_stream_off`
and you return from 'ov5647_set_stream' immediately if 'mode == current_mode'
it seem very similar to returning immediately from 'ov5647_set_stream' if the
device is currently streaming.
But actually in this patch it seems to be possible to change the mode
while streaming, if the callbacks are executed:
s_stream(1)
s_fmt
s_stream(1)
which is maybe a bug?
Thanks,
Dafna
>
> Thanks
> j
>
>
>>
>> Thanks,
>> Dafna
>>
>>>
>>> Signed-off-by: Jacopo Mondi <jacopo at jmondi.org>
>>> ---
>>> drivers/media/i2c/ov5647.c | 16 +++++++++++++++-
>>> 1 file changed, 15 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/media/i2c/ov5647.c b/drivers/media/i2c/ov5647.c
>>> index 39e320f321bd8..ac114269e1c73 100644
>>> --- a/drivers/media/i2c/ov5647.c
>>> +++ b/drivers/media/i2c/ov5647.c
>>> @@ -96,6 +96,7 @@ struct ov5647 {
>>> bool clock_ncont;
>>> struct v4l2_ctrl_handler ctrls;
>>> struct ov5647_mode *mode;
>>> + struct ov5647_mode *current_mode;
>>> };
>>> static inline struct ov5647 *to_sensor(struct v4l2_subdev *sd)
>>> @@ -750,9 +751,13 @@ static int ov5647_set_virtual_channel(struct v4l2_subdev *sd, int channel)
>>> static int ov5647_set_mode(struct v4l2_subdev *sd)
>>> {
>>> struct i2c_client *client = v4l2_get_subdevdata(sd);
>>> + struct ov5647 *sensor = to_sensor(sd);
>>> u8 resetval, rdval;
>>> int ret;
>>> + if (sensor->mode == sensor->current_mode)
>>> + return 0;
>>> +
>>> ret = ov5647_read(sd, OV5647_SW_STANDBY, &rdval);
>>> if (ret < 0)
>>> return ret;
>>> @@ -778,6 +783,8 @@ static int ov5647_set_mode(struct v4l2_subdev *sd)
>>> return ret;
>>> }
>>> + sensor->current_mode = sensor->mode;
>>> +
>>> return 0;
>>> }
>>> @@ -816,6 +823,7 @@ static int ov5647_stream_on(struct v4l2_subdev *sd)
>>> static int ov5647_stream_off(struct v4l2_subdev *sd)
>>> {
>>> + struct ov5647 *sensor = to_sensor(sd);
>>> int ret;
>>> ret = ov5647_write(sd, OV5647_REG_MIPI_CTRL00, MIPI_CTRL00_CLOCK_LANE_GATE |
>>> @@ -827,7 +835,13 @@ static int ov5647_stream_off(struct v4l2_subdev *sd)
>>> if (ret < 0)
>>> return ret;
>>> - return ov5647_write(sd, OV5640_REG_PAD_OUT, 0x01);
>>> + ret = ov5647_write(sd, OV5640_REG_PAD_OUT, 0x01);
>>> + if (ret < 0)
>>> + return ret;
>>> +
>>> + sensor->current_mode = NULL;
>>> +
>>> + return 0;
>>> }
>>> static int set_sw_standby(struct v4l2_subdev *sd, bool standby)
>>>
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