From: Jacopo Mondi <jacopo@jmondi.org>
To: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Jacopo Mondi <jacopo+renesas@jmondi.org>,
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: Fri, 26 Mar 2021 12:22:40 +0100 [thread overview]
Message-ID: <20210326112240.eqoo7lpwhbmtaqq5@uno.localdomain> (raw)
In-Reply-To: <YFYaMh832WYlsR9u@pendragon.ideasonboard.com>
Hi Laurent, Kieran,
On Sat, Mar 20, 2021 at 05:52:18PM +0200, Laurent Pinchart wrote:
> 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.
No, it's 250usecond before releasing it. After the OV490 is released
from reset there's a 3-5 milliseconds sleep below.
> >
> > Perhaps possible to update the comment a little, but nothing that matters.
>
> The commit message and comment should match the code, especially given
They do if I'm not mistaken.
> 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
next prev parent reply other threads:[~2021-03-26 11:22 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
2021-03-26 11:22 ` Jacopo Mondi [this message]
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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