From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 13EFDC433E1 for ; Fri, 26 Mar 2021 11:22:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CA10261A4A for ; Fri, 26 Mar 2021 11:22:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229893AbhCZLWO (ORCPT ); Fri, 26 Mar 2021 07:22:14 -0400 Received: from relay5-d.mail.gandi.net ([217.70.183.197]:46721 "EHLO relay5-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229935AbhCZLWM (ORCPT ); Fri, 26 Mar 2021 07:22:12 -0400 X-Originating-IP: 93.34.118.233 Received: from uno.localdomain (93-34-118-233.ip49.fastwebnet.it [93.34.118.233]) (Authenticated sender: jacopo@jmondi.org) by relay5-d.mail.gandi.net (Postfix) with ESMTPSA id 231141C0004; Fri, 26 Mar 2021 11:22:07 +0000 (UTC) Date: Fri, 26 Mar 2021 12:22:40 +0100 From: Jacopo Mondi To: Laurent Pinchart Cc: Jacopo Mondi , Kieran Bingham , niklas.soderlund+renesas@ragnatech.se, geert@linux-m68k.org, Mauro Carvalho Chehab , 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 Message-ID: <20210326112240.eqoo7lpwhbmtaqq5@uno.localdomain> References: <20210319164148.199192-1-jacopo+renesas@jmondi.org> <20210319164148.199192-12-jacopo+renesas@jmondi.org> <99971a13-4d02-2255-6653-569915da181d@ideasonboard.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org 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 > > > --- > > > 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 > > > > > > > ret = max9271_configure_gmsl_link(&dev->serializer); > > > if (ret) > > > > > -- > Regards, > > Laurent Pinchart