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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2D0EAC4332F for ; Mon, 17 Oct 2022 08:29:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229930AbiJQI3f (ORCPT ); Mon, 17 Oct 2022 04:29:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56158 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229760AbiJQI3a (ORCPT ); Mon, 17 Oct 2022 04:29:30 -0400 Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [213.167.242.64]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9E3CFDB7; Mon, 17 Oct 2022 01:29:23 -0700 (PDT) Received: from pendragon.ideasonboard.com (62-78-145-57.bb.dnainternet.fi [62.78.145.57]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 1BFE6CCF; Mon, 17 Oct 2022 10:29:21 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1665995361; bh=sVZCLSgX6k6MUk9kICNW2SQeppujn+8ITE9dOx6WEps=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=TQhfME+rXpgkfi5VecYtgR3HKbcRwya1/4W3jPJMEBnxuiGmSzEyzF2XdDd5Y+wqR IGqbu1ShhI9VMJN/B9CpfUkn6ENgIDt+qpphx4KYNYu7HkDHvdukGGInjGgaMRe8hK JGAWGgxTkYSfaF/PeWIXn3jh9cPWDq/13EuBbxJA= Date: Mon, 17 Oct 2022 11:28:57 +0300 From: Laurent Pinchart To: Dorota Czaplejewicz Cc: Steve Longerbeam , Philipp Zabel , Mauro Carvalho Chehab , Greg Kroah-Hartman , Shawn Guo , Sascha Hauer , Pengutronix Kernel Team , Fabio Estevam , NXP Linux Team , linux-media@vger.kernel.org, linux-staging@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, kernel@puri.sm, phone-devel@vger.kernel.org Subject: Re: [PATCHv3 1/1 RESEND] media: imx: Round line size to 4 bytes Message-ID: References: <20221016163928.1ef0a4fe.dorota.czaplejewicz@puri.sm> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20221016163928.1ef0a4fe.dorota.czaplejewicz@puri.sm> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Dorota, Thank you for the patch. On Sun, Oct 16, 2022 at 04:39:28PM +0200, Dorota Czaplejewicz wrote: > Section 13.7.6.13 "CSI Image Parameter Register" of the > i.MX 8M Quad Applications Processors Reference Manual > states that the line size should be divisible by 8 bytes. > However, the hardware also accepts sizes divisible by 4 bytes, > which are needed to fully utilize the S5K3L6XX sensors. > > This patch accepts line sizes divisible by 4 bytes. The patch itself looks fine, but I always worry when we depart from the documentation (sometimes that's a worry about documentation inaccuracies :-)). In this particular case, we need to test the change on i.MX7 too, as the alignment constraints could be platform-specific. I would also very much appreciate feedback from NXP on this. There's a risk of ill side-effects that I would prefer ruling out very clearly. > Signed-off-by: Dorota Czaplejewicz > --- > Hello, > > the Librem 5 is using an out-of-tree driver for s5k3l6xx, and rounding to 4 is optimal to operate it. > > This revision improves the commit message. > > Cheers, > Dorota Czaplejewicz > > drivers/staging/media/imx/imx7-media-csi.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/staging/media/imx/imx7-media-csi.c b/drivers/staging/media/imx/imx7-media-csi.c > index a0553c24cce4..af821b410c3f 100644 > --- a/drivers/staging/media/imx/imx7-media-csi.c > +++ b/drivers/staging/media/imx/imx7-media-csi.c > @@ -999,10 +999,10 @@ static int imx7_csi_mbus_fmt_to_pix_fmt(struct v4l2_pix_format *pix, > } > > /* Round up width for minimum burst size */ > - width = round_up(mbus->width, 8); > + width = round_up(mbus->width, 4); > > /* Round up stride for IDMAC line start address alignment */ > - stride = round_up((width * cc->bpp) >> 3, 8); > + stride = round_up((width * cc->bpp) >> 3, 4); > > pix->width = width; > pix->height = mbus->height; -- Regards, Laurent Pinchart