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=-17.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 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 1E0E5C4361B for ; Mon, 7 Dec 2020 10:48:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BD2E723339 for ; Mon, 7 Dec 2020 10:48:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726421AbgLGKs0 (ORCPT ); Mon, 7 Dec 2020 05:48:26 -0500 Received: from lb3-smtp-cloud9.xs4all.net ([194.109.24.30]:46271 "EHLO lb3-smtp-cloud9.xs4all.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726214AbgLGKsZ (ORCPT ); Mon, 7 Dec 2020 05:48:25 -0500 Received: from cust-b5b5937f ([IPv6:fc0c:c16d:66b8:757f:c639:739b:9d66:799d]) by smtp-cloud9.xs4all.net with ESMTPA id mE3OkFNsIarN7mE3SkzDir; Mon, 07 Dec 2020 11:47:42 +0100 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=xs4all.nl; s=s2; t=1607338062; bh=gWVo8YX1VQxSsOSI04pPBsnfOvUw7NtMunA1qyzkVps=; h=Subject:To:From:Message-ID:Date:MIME-Version:Content-Type:From: Subject; b=jKT/DwFs1uxnlPjVbuxcBc5m36tgdSbbBheMmi5rQbE/2Nlq/zWY4tTjVlvcf5Dyz oCr3qxpIELZgr6ldAsAloZ2oU1vnHrpTd5pkVUE7CQhocWJPqJuBC41kWSjhaOnO+H 0ZjJ3GJHq0XiHdoiojc8thNUGtjROedHn1s18kAY2k2iKsle5rgDfuG9D3cIyiZ1sl 6K+OpjgG8+rnJUk/qzXN5E20ax0F+tVO4OpMKanuUMMqgPj5GtFc8codZ8Z6ynxKDp rzsdp7+WoDml73Y7EzIh3WZpXK+UDL5OBkgGHXxeryJ2vrXFG/4jiGlvcIZQj+16zi e3SVhAVoaW4uw== Subject: Re: [PATCH v3 10/13] media: v4l2-fwnode: Update V4L2_FWNODE_CSI2_MAX_DATA_LANES to 8 To: Sowjanya Komatineni , thierry.reding@gmail.com, jonathanh@nvidia.com, sakari.ailus@iki.fi, robh+dt@kernel.org Cc: bparrot@ti.com, mchehab@kernel.org, linux-media@vger.kernel.org, linux-tegra@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Laurent Pinchart References: <1607022002-26575-1-git-send-email-skomatineni@nvidia.com> <1607022002-26575-11-git-send-email-skomatineni@nvidia.com> From: Hans Verkuil Message-ID: <845dfd4a-fa11-625c-78a3-cc8adc68bfc7@xs4all.nl> Date: Mon, 7 Dec 2020 11:47:38 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.12.0 MIME-Version: 1.0 In-Reply-To: <1607022002-26575-11-git-send-email-skomatineni@nvidia.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-CMAE-Envelope: MS4xfKlT91V/9qHoNEbQguLdjtrxEusCqooMka1R1Z25DwFG17wT85odnqoeRsm++0Zzch7a8bH+1di0wpastSoZvVELgKJHd/ZJy5CDBZfTD4bwan22gYMV C7KxBboHLhb1Yptt6u1/jkYzVOvNlqcQQRybr6eFb39d5eGgLihAdmflsBBbDI/pCvtlypxfrRcaEUW8TO+2TXec3MfbNPqzxlYDnOJ1ouBYRK53ergZUGEb 97/E/JWkam3FjIZhszOQPO8hYKAm7GN3JUc2ofaYgv/d4rjS8bYFAB4ADiFkt8kt++1yW3sVIzwHdyNOogRa8Ynr9KKXEWQt4N9VgH3zjhWbZdMR8TZwEdTX aMOtQwlkHub9zJxCo/HQDifMk5m+tep8yWzezayO24YeCUnqtlYlYIKvwtuWZP5PBJR4EXTIcF/GYhAGcjYFP7qZCLb7itRjYKMDmYYrzzLryFSPwYPREY6U oyFjX8XMBNMidSuLoqqaj6wM8cJb5gEfzaze1MzYRaLj2LSzdDXPb61Grf0PBun3ntGl/2OGXTS/58LXblSEQmlH8Mem3aBwPagSPERyztfL6JT9pGiViHJE C8E= Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 03/12/2020 19:59, Sowjanya Komatineni wrote: > Some CSI2 receivers support 8 data lanes. > > So, this patch updates CSI2 maximum data lanes to be 8. > > Signed-off-by: Sowjanya Komatineni > --- > drivers/media/platform/ti-vpe/cal-camerarx.c | 2 +- > include/media/v4l2-fwnode.h | 2 +- > 2 files changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/media/platform/ti-vpe/cal-camerarx.c b/drivers/media/platform/ti-vpe/cal-camerarx.c > index 806cbf1..47e2143 100644 > --- a/drivers/media/platform/ti-vpe/cal-camerarx.c > +++ b/drivers/media/platform/ti-vpe/cal-camerarx.c > @@ -534,7 +534,7 @@ static int cal_camerarx_parse_dt(struct cal_camerarx *phy) > { > struct v4l2_fwnode_endpoint *endpoint = &phy->endpoint; > struct device_node *ep_node; > - char data_lanes[V4L2_FWNODE_CSI2_MAX_DATA_LANES * 2]; > + char data_lanes[V4L2_FWNODE_CSI2_MAX_DATA_LANES]; > unsigned int i; > int ret; > I'm not so sure about this change: it relies on the implicit knowledge that this cal driver can handle only 4 lanes max, so that doubling V4L2_FWNODE_CSI2_MAX_DATA_LANES is the same as the old 'V4L2_FWNODE_CSI2_MAX_DATA_LANES * 2'. I think we should either keep the existing code (which means data_lanes is now larger than needed, so stack usage increases by 8 bytes), or perhaps create a new define for this driver like CAL_MAX_DATA_LANES and use that. In my opinion the original code should just be kept, but I've CC-ed Laurent on this to hear what he thinks. Regards, Hans > diff --git a/include/media/v4l2-fwnode.h b/include/media/v4l2-fwnode.h > index 4e1f6e1d..92401c1 100644 > --- a/include/media/v4l2-fwnode.h > +++ b/include/media/v4l2-fwnode.h > @@ -25,7 +25,7 @@ struct fwnode_handle; > struct v4l2_async_notifier; > struct v4l2_async_subdev; > > -#define V4L2_FWNODE_CSI2_MAX_DATA_LANES 4 > +#define V4L2_FWNODE_CSI2_MAX_DATA_LANES 8 > > /** > * struct v4l2_fwnode_bus_mipi_csi2 - MIPI CSI-2 bus data structure >