linux-kernel - Re: [PATCH v4 09/10] media: i2c: ov9282: add strobe

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <jsohv4yhopqla6gvae76qqtat7ekeqxvjvxvcaxjaw2th7hq32@uupjpwho3b5d>
Date: Wed, 28 May 2025 11:46:37 +0200
From: Richard Leitner <richard.leitner@...ux.dev>
To: Sakari Ailus <sakari.ailus@...ux.intel.com>
Cc: Dave Stevenson <dave.stevenson@...pberrypi.com>, 
	Mauro Carvalho Chehab <mchehab@...nel.org>, Lee Jones <lee@...nel.org>, Pavel Machek <pavel@...nel.org>, 
	Laurent Pinchart <laurent.pinchart@...asonboard.com>, Hans Verkuil <hverkuil@...all.nl>, linux-media@...r.kernel.org, 
	linux-kernel@...r.kernel.org, linux-leds@...r.kernel.org
Subject: Re: [PATCH v4 09/10] media: i2c: ov9282: add strobe_source v4l2
 control

On Mon, May 26, 2025 at 08:24:40PM +0000, Sakari Ailus wrote:
> Hi Richard,

Hi Sakari,

thanks for the review!

> 
> On Wed, May 07, 2025 at 09:51:38AM +0200, Richard Leitner wrote:
> > Add read-only V4L2_CID_FLASH_STROBE_SOURCE control. Its value is fixed
> > to V4L2_FLASH_STROBE_SOURCE_EXTERNAL as the camera sensor triggers the
> > strobe based on its register settings.
> 
> Is strobe source control relevant for the sensor? It's triggering the flash
> but the flash LED isn't connected to it, is it?

Exactly. The sensor is only triggering a "strobe output" pin, but no
LEDs are on the sensor module. Nonetheless at least in our use-case the LEDs
are switched directly by this output pin of the sensor (via some FET
circuit).

So to be honest I don't know if it is relevant, or not. I guess the
sensor in this case is a "external strobe source" as seen from the
kernel, isn't it?

> 
> > 
> > Signed-off-by: Richard Leitner <richard.leitner@...ux.dev>
> > ---
> >  drivers/media/i2c/ov9282.c | 11 ++++++++++-
> >  1 file changed, 10 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/media/i2c/ov9282.c b/drivers/media/i2c/ov9282.c
> > index 0bbdf08d7cda8f72e05fdc292aa69a4c821e4e03..09d522d5977ec6fb82028ddb6015f05c9328191d 100644
> > --- a/drivers/media/i2c/ov9282.c
> > +++ b/drivers/media/i2c/ov9282.c
> > @@ -1368,11 +1368,12 @@ static int ov9282_init_controls(struct ov9282 *ov9282)
> >  	struct v4l2_ctrl_handler *ctrl_hdlr = &ov9282->ctrl_handler;
> >  	const struct ov9282_mode *mode = ov9282->cur_mode;
> >  	struct v4l2_fwnode_device_properties props;
> > +	struct v4l2_ctrl *ctrl;
> >  	u32 hblank_min;
> >  	u32 lpfr;
> >  	int ret;
> >  
> > -	ret = v4l2_ctrl_handler_init(ctrl_hdlr, 12);
> > +	ret = v4l2_ctrl_handler_init(ctrl_hdlr, 13);
> >  	if (ret)
> >  		return ret;
> >  
> > @@ -1447,6 +1448,14 @@ static int ov9282_init_controls(struct ov9282 *ov9282)
> >  	v4l2_ctrl_new_std(ctrl_hdlr, &ov9282_ctrl_ops, V4L2_CID_FLASH_DURATION,
> >  			  0, 13900, 1, 8);
> >  
> > +	ctrl = v4l2_ctrl_new_std_menu(ctrl_hdlr, &ov9282_ctrl_ops,
> > +				      V4L2_CID_FLASH_STROBE_SOURCE,
> > +				      V4L2_FLASH_STROBE_SOURCE_EXTERNAL,
> > +				      ~(1 << V4L2_FLASH_STROBE_SOURCE_EXTERNAL),
> > +				      V4L2_FLASH_STROBE_SOURCE_EXTERNAL);
> > +	if (ctrl)
> > +		ctrl->flags |= V4L2_CTRL_FLAG_READ_ONLY;
> > +
> >  	ret = v4l2_fwnode_device_parse(ov9282->dev, &props);
> >  	if (!ret) {
> >  		/* Failure sets ctrl_hdlr->error, which we check afterwards anyway */
> > 
> 
> -- 
> Regards,
> 
> Sakari Ailus

thanks & regards;rl