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=-3.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_NEOMUTT 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 684A5C282CB for ; Fri, 8 Feb 2019 23:18:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3FF8320836 for ; Fri, 8 Feb 2019 23:18:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726860AbfBHXR4 (ORCPT ); Fri, 8 Feb 2019 18:17:56 -0500 Received: from mga04.intel.com ([192.55.52.120]:55824 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726353AbfBHXRz (ORCPT ); Fri, 8 Feb 2019 18:17:55 -0500 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga104.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 08 Feb 2019 15:17:55 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.58,348,1544515200"; d="scan'208";a="318829222" Received: from sshumihi-mobl.ccr.corp.intel.com (HELO mara.localdomain) ([10.252.20.76]) by fmsmga005.fm.intel.com with ESMTP; 08 Feb 2019 15:17:51 -0800 Received: from sailus by mara.localdomain with local (Exim 4.89) (envelope-from ) id 1gsFP2-0005a0-DG; Sat, 09 Feb 2019 01:17:49 +0200 Date: Sat, 9 Feb 2019 01:17:47 +0200 From: Sakari Ailus To: Maxime Ripard Cc: Hans Verkuil , Mauro Carvalho Chehab , Thomas Petazzoni , Laurent Pinchart , linux-media@vger.kernel.org, Andrzej Hajda , Chen-Yu Tsai , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org, Mark Rutland , Rob Herring , Frank Rowand Subject: Re: [PATCH v2 3/5] media: sunxi: Add A10 CSI driver Message-ID: <20190208231746.sjgb7im6xqsawhwz@mara.localdomain> References: <20190129123949.qdmqnfaym3y42dvj@paasikivi.fi.intel.com> <20190206211605.27cq2lxuv3gtyyux@flea> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190206211605.27cq2lxuv3gtyyux@flea> User-Agent: NeoMutt/20170113 (1.7.2) Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org Hi Maxime, On Wed, Feb 06, 2019 at 10:16:05PM +0100, Maxime Ripard wrote: > Hi Sakari, > > Thanks for your review, I have a few questions though, and the rest > will be addressed in the next version. > > On Tue, Jan 29, 2019 at 02:39:49PM +0200, Sakari Ailus wrote: > > > +static int csi_notify_complete(struct v4l2_async_notifier *notifier) > > > +{ > > > + struct sun4i_csi *csi = container_of(notifier, struct sun4i_csi, > > > + notifier); > > > + int ret; > > > + > > > + ret = v4l2_device_register_subdev_nodes(&csi->v4l); > > > + if (ret < 0) > > > + return ret; > > > + > > > + ret = sun4i_csi_v4l2_register(csi); > > > + if (ret < 0) > > > + return ret; > > > + > > > + return media_create_pad_link(&csi->src_subdev->entity, csi->src_pad, > > > + &csi->vdev.entity, 0, > > > + MEDIA_LNK_FL_ENABLED | > > > + MEDIA_LNK_FL_IMMUTABLE); > > > > This appears to create a link directly from the sensor entity to the video > > device entity. Is that intentional? I'd expect to see a CSI-2 receiver > > sub-device as well, which I don't see being created by the driver. > > > > This is indeed a novel proposal. I have some concerns though. > > > > The user doesn't have access to the configured media bus format (reflecting > > the format on the CSI-2 bus on receiver's side). It's thus difficult to > > figure out whether the V4L2 pixel format configured on the video node > > matches what the sensor outputs. Admittedly, we don't have a perfect > > solution to that whenever the DMA hardware supports multiple V4L2 pixel > > formats on a single media bus format. We might need to have a different > > solution for this one, should it be without that receiver sub-device. > > > > Could you add the CSI-2 receiver sub-device, please? > > Even though the name of the controller is *very* confusing, this isn't > a MIPI-CSI receiver, but a parallel one that supports RGB and BT656 > buses. Right. > > > > + csi->pad.flags = MEDIA_PAD_FL_SINK | MEDIA_PAD_FL_MUST_CONNECT; > > > > Could you make it IMMUTABLE and ENABLED? If there is no need to disable it, > > that is. > > The link is already created with those flags, and as far as I know it > doesn't exist for the pads Oops. And it wasn't even late when I reviewed the patch. :-P Please ignore the comment --- I agree on the pad flags and the link flags (some lines up) appear fine, too. > > > > +static int csi_release(struct file *file) > > > +{ > > > + struct sun4i_csi *csi = video_drvdata(file); > > > + int ret; > > > + > > > + mutex_lock(&csi->lock); > > > + > > > + ret = v4l2_fh_release(file); > > > > v4l2_fh_release() always returns 0. I guess it could be changed to return > > void. The reason it has int is that it could be used as the release > > callback as such. > > > > > + v4l2_pipeline_pm_use(&csi->vdev.entity, 0); > > > + pm_runtime_put(csi->dev); > > > + > > > + mutex_unlock(&csi->lock); > > > + > > > + return ret; > > > +} > > Do you want me to change the construct then? Please. -- Kind regards, Sakari Ailus sakari.ailus@linux.intel.com