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From: Richard Leitner <richard.leitner@linux.dev>
To: Dave Stevenson <dave.stevenson@raspberrypi.com>
Cc: Sakari Ailus <sakari.ailus@linux.intel.com>,
	 Mauro Carvalho Chehab <mchehab@kernel.org>,
	Martina Krasteva <martinax.krasteva@intel.com>,
	 "Paul J. Murphy" <paul.j.murphy@intel.com>,
	Daniele Alessandrelli <daniele.alessandrelli@gmail.com>,
	 Hans Verkuil <hverkuil+cisco@kernel.org>,
	Mauro Carvalho Chehab <mchehab+huawei@kernel.org>,
	 Gyula Kelemen <gyula.kelemen@advasolutions.com>,
	linux-media@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 04/10] media: i2c: ov9282: update flash_duration range even when powered down
Date: Mon, 28 Sep 2026 09:54:08 +0200	[thread overview]
Message-ID: <aroc9bgzdPns60fG@bombadil> (raw)
In-Reply-To: <CAPY8ntAyYq_54Yvo1uC=LBepmqLma8mz_rYTmsm62LzHkixX7A@mail.gmail.com>

Hi Dave,
thanks for your feedback!

On Thu, Sep 17, 2026 at 11:38:22AM +0100, Dave Stevenson wrote:
> Hi Richard
> 
> On Mon, 14 Sept 2026 at 20:21, Richard Leitner
> <richard.leitner@linux.dev> wrote:
> >
> > The flash_duration range update sat inside ov9282_update_exp_gain(), which
> > ov9282_set_ctrl() only reaches after the pm_runtime_get_if_in_use() early
> > return. So with the sensor idle the ceiling kept whatever value it had
> > when it last streamed. Therefore setting exposure before flash_duration
> > while the sensor is powered down may clamp flash_duration against an
> > outdated exposure.
> >
> > Fix this by moving the range update before the power check.
> >
> > Signed-off-by: Richard Leitner <richard.leitner@linux.dev>
> > ---
> >  drivers/media/i2c/ov9282.c | 13 +++++++++++++
> >  1 file changed, 13 insertions(+)
> >
> > diff --git a/drivers/media/i2c/ov9282.c b/drivers/media/i2c/ov9282.c
> > index 90a0fe542ce4a..4c88de1965171 100644
> > --- a/drivers/media/i2c/ov9282.c
> > +++ b/drivers/media/i2c/ov9282.c
> > @@ -645,6 +645,19 @@ static int ov9282_set_ctrl(struct v4l2_ctrl *ctrl)
> >                 if (ret)
> >                         return ret;
> >                 break;
> > +       case V4L2_CID_EXPOSURE:
> > +               /*
> > +                * Ensure the flash duration range is also updated on powered
> > +                * down sensors.
> > +                */
> > +               ret = __v4l2_ctrl_modify_range(ov9282->flash_duration, 0,
> > +                                              ov9282_exposure_to_us(ov9282,
> > +                                                                    ctrl->val),
> > +                                              1,
> > +                                              OV9282_STROBE_FRAME_SPAN_DEFAULT);
> > +               if (ret)
> > +                       return ret;
> > +               break;
> 
> This hasn't removed the __v4l2_ctrl_modify_range call from
> ov9282_update_exp_gain(), so the range gets updated twice if the
> sensor is powered on.

I will take a look at it and adapt it for v2 accordingly.

regards;rl

> 
>   Dave
> 
> >         }
> >
> >         /* Set controls only if sensor is in power on state */
> >
> > --
> > 2.53.0
> >
> >

  reply	other threads:[~2026-09-28  7:54 UTC|newest]

Thread overview: 37+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-09-14 19:20 [PATCH 00/10] media: i2c: ov9282: fix control range handling Richard Leitner
2026-09-14 19:20 ` [PATCH 01/10] media: i2c: ov9282: handle error from exposure range update Richard Leitner
2026-09-15 14:19   ` Dave Stevenson
2026-09-14 19:20 ` [PATCH 02/10] media: i2c: ov9282: fix line time and exposure time calculation Richard Leitner
2026-09-17 10:51   ` Bryan O'Donoghue
2026-09-17 13:38     ` Richard Leitner
2026-09-23 14:16   ` Dave Stevenson
2026-09-28  8:56     ` Richard Leitner
2026-09-28 11:02       ` Dave Stevenson
2026-09-28 11:24         ` Richard Leitner
2026-09-14 19:21 ` [PATCH 03/10] media: i2c: ov9282: fix flash duration to/from microseconds conversion Richard Leitner
2026-09-17 10:53   ` Bryan O'Donoghue
2026-09-28  8:01     ` Richard Leitner
2026-09-28 11:07   ` Dave Stevenson
2026-09-28 11:31     ` Richard Leitner
2026-09-14 19:21 ` [PATCH 04/10] media: i2c: ov9282: update flash_duration range even when powered down Richard Leitner
2026-09-17 10:38   ` Dave Stevenson
2026-09-28  7:54     ` Richard Leitner [this message]
2026-09-14 19:21 ` [PATCH 05/10] media: i2c: ov9282: add refresh of missing ranges on a mode change Richard Leitner
2026-09-28 13:15   ` Dave Stevenson
2026-09-28 14:39     ` Richard Leitner
2026-09-14 19:21 ` [PATCH 06/10] media: i2c: ov9282: refresh flash_duration range on an HBLANK write Richard Leitner
2026-09-23 15:09   ` Dave Stevenson
2026-09-28  8:15     ` Richard Leitner
2026-09-14 19:21 ` [PATCH 07/10] media: i2c: ov9282: drop redundant vblank field Richard Leitner
2026-09-15 14:42   ` Dave Stevenson
2026-09-14 19:21 ` [PATCH 08/10] media: i2c: ov9282: harmonize dev_err_probe usage Richard Leitner
2026-09-15 14:55   ` Dave Stevenson
2026-09-15 19:51     ` Richard Leitner
2026-09-14 19:21 ` [PATCH 09/10] media: i2c: ov9282: fix flash duration control range Richard Leitner
2026-09-28 13:47   ` Dave Stevenson
2026-09-28 14:23     ` Richard Leitner
2026-09-28 14:40       ` Dave Stevenson
2026-09-28 21:08         ` Richard Leitner
2026-09-14 19:21 ` [PATCH 10/10] media: i2c: ov9282: clamp flash_duration default to its maximum Richard Leitner
2026-09-15 15:09   ` Dave Stevenson
2026-09-15 19:43     ` Richard Leitner

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