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From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
To: Jacopo Mondi <jacopo+renesas@jmondi.org>
Cc: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>,
	niklas.soderlund+renesas@ragnatech.se, geert@linux-m68k.org,
	Mauro Carvalho Chehab <mchehab@kernel.org>,
	linux-media@vger.kernel.org, linux-renesas-soc@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3 11/19] media: i2c: rdacm21: Add dealy after OV490 reset
Date: Sat, 20 Mar 2021 17:52:18 +0200	[thread overview]
Message-ID: <YFYaMh832WYlsR9u@pendragon.ideasonboard.com> (raw)
In-Reply-To: <99971a13-4d02-2255-6653-569915da181d@ideasonboard.com>

Hi Jacopo,

Thank you for the patch.

On Fri, Mar 19, 2021 at 04:49:44PM +0000, Kieran Bingham wrote:
> Hi Jacopo,
> 
> s/dealy/delay/ in $SUBJECT
> 
> On 19/03/2021 16:41, Jacopo Mondi wrote:
> > Add a delay after the OV490 chip is put in reset state. The reset
> > signal shall be held for at least 250 useconds.
> > 
> > Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
> > ---
> >  drivers/media/i2c/rdacm21.c | 6 +++++-
> >  1 file changed, 5 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/media/i2c/rdacm21.c b/drivers/media/i2c/rdacm21.c
> > index babd14b21252..875bec9f7904 100644
> > --- a/drivers/media/i2c/rdacm21.c
> > +++ b/drivers/media/i2c/rdacm21.c
> > @@ -448,7 +448,10 @@ static int rdacm21_init(struct v4l2_subdev *sd, unsigned int val)
> >  	if (ret)
> >  		return ret;
> >  
> > -	/* Enable GPIO1 and hold OV490 in reset during max9271 configuration. */
> > +	/*
> > +	 * Enable GPIO1 and hold OV490 in reset during max9271 configuration.
> > +	 * The reset signal has to be asserted for at least 250 useconds.
> > +	 */
> >  	ret = max9271_enable_gpios(&dev->serializer, MAX9271_GPIO1OUT);
> >  	if (ret)
> >  		return ret;
> > @@ -456,6 +459,7 @@ static int rdacm21_init(struct v4l2_subdev *sd, unsigned int val)
> >  	ret = max9271_clear_gpios(&dev->serializer, MAX9271_GPIO1OUT);
> >  	if (ret)
> >  		return ret;
> > +	usleep_range(250, 500);
> 
> Aha, for a second there I thought the comment meant it had to be
> asserted for 250 uS before clearing it again. But it's 250 uS before
> using the OV490.
> 
> Perhaps possible to update the comment a little, but nothing that matters.

The commit message and comment should match the code, especially given
that I'm not sure here which of the two is actually incorrect. I suspect
the sleep is actually in the wrong location.

> Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
> 
> 
> >  	ret = max9271_configure_gmsl_link(&dev->serializer);
> >  	if (ret)
> > 

-- 
Regards,

Laurent Pinchart

  reply	other threads:[~2021-03-20 15:53 UTC|newest]

Thread overview: 34+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-03-19 16:41 [PATCH v3 00/19] media: gmsl: Reliability improvement Jacopo Mondi
2021-03-19 16:41 ` [PATCH v3 01/19] media: i2c: max9286: Adjust parameters indent Jacopo Mondi
2021-03-19 16:41 ` [PATCH v3 02/19] media: i2c: max9286: Rename reverse_channel_mv Jacopo Mondi
2021-03-19 16:41 ` [PATCH v3 03/19] media: i2c: max9286: Cache channel amplitude Jacopo Mondi
2021-03-19 16:41 ` [PATCH v3 04/19] media: i2c: max9286: Define high " Jacopo Mondi
2021-03-19 16:41 ` [PATCH v3 05/19] media: v4l2-subdev: De-deprecate init() subdev op Jacopo Mondi
2021-03-20 15:42   ` Laurent Pinchart
2021-03-21 20:52     ` Sakari Ailus
2021-03-22 12:51       ` Jacopo Mondi
2021-03-26 11:37         ` Jacopo Mondi
2021-03-19 16:41 ` [PATCH v3 06/19] media: gmsl: Reimplement initialization sequence Jacopo Mondi
2021-03-20 15:46   ` Laurent Pinchart
2021-03-19 16:41 ` [PATCH v3 07/19] media: i2c: max9286: Rework comments in .bound() Jacopo Mondi
2021-03-19 16:41 ` [PATCH v3 08/19] media: i2c: max9271: Check max9271_write() return Jacopo Mondi
2021-03-19 16:41 ` [PATCH v3 09/19] media: i2c: max9271: Introduce wake_up() function Jacopo Mondi
2021-03-19 16:41 ` [PATCH v3 10/19] media: i2c: rdamc21: Fix warning on u8 cast Jacopo Mondi
2021-03-19 16:41 ` [PATCH v3 11/19] media: i2c: rdacm21: Add dealy after OV490 reset Jacopo Mondi
2021-03-19 16:49   ` Kieran Bingham
2021-03-20 15:52     ` Laurent Pinchart [this message]
2021-03-26 11:22       ` Jacopo Mondi
2021-03-19 16:41 ` [PATCH v3 12/19] media: i2c: rdacm21: Fix OV10640 powerup Jacopo Mondi
2021-03-19 16:41 ` [PATCH v3 13/19] media: i2c: rdacm21: Power up OV10640 before OV490 Jacopo Mondi
2021-03-20 16:14   ` Laurent Pinchart
2021-03-26 11:07     ` Jacopo Mondi
2021-03-19 16:41 ` [PATCH v3 14/19] media: i2c: rdacm20: Enable noise immunity Jacopo Mondi
2021-03-20 16:16   ` Laurent Pinchart
2021-03-19 16:41 ` [PATCH v3 15/19] media: i2c: rdacm20: Embed 'serializer' field Jacopo Mondi
2021-03-19 16:41 ` [PATCH v3 16/19] media: i2c: rdacm20: Replace goto with a loop Jacopo Mondi
2021-03-20 16:17   ` Laurent Pinchart
2021-03-19 16:41 ` [PATCH v3 17/19] media: i2c: rdacm20: Report camera module name Jacopo Mondi
2021-03-19 16:41 ` [PATCH v3 18/19] media: i2c: rdacm20: Check return values Jacopo Mondi
2021-03-19 16:41 ` [PATCH v3 19/19] media: i2c: rdacm20: Re-work ov10635 reset Jacopo Mondi
2021-03-20 16:24   ` Laurent Pinchart
2021-03-26 11:11     ` Jacopo Mondi

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