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_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 677E5C04AB5 for ; Thu, 6 Jun 2019 12:12:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4C24C2070B for ; Thu, 6 Jun 2019 12:12:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728103AbfFFMMq (ORCPT ); Thu, 6 Jun 2019 08:12:46 -0400 Received: from mga04.intel.com ([192.55.52.120]:19764 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726757AbfFFMMq (ORCPT ); Thu, 6 Jun 2019 08:12:46 -0400 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; 06 Jun 2019 05:12:45 -0700 X-ExtLoop1: 1 Received: from paasikivi.fi.intel.com ([10.237.72.42]) by fmsmga005.fm.intel.com with ESMTP; 06 Jun 2019 05:12:39 -0700 Received: by paasikivi.fi.intel.com (Postfix, from userid 1000) id E6E6C20D69; Thu, 6 Jun 2019 15:12:38 +0300 (EEST) Date: Thu, 6 Jun 2019 15:12:38 +0300 From: Sakari Ailus To: Vishal Sagar Cc: Vishal Sagar , Hyun Kwon , "laurent.pinchart@ideasonboard.com" , "mchehab@kernel.org" , "robh+dt@kernel.org" , "mark.rutland@arm.com" , Michal Simek , "linux-media@vger.kernel.org" , "devicetree@vger.kernel.org" , "hans.verkuil@cisco.com" , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" , Dinesh Kumar , Sandip Kothari , Luca Ceresoli , Jacopo Mondi Subject: Re: [PATCH v8 1/2] media: dt-bindings: media: xilinx: Add Xilinx MIPI CSI-2 Rx Subsystem Message-ID: <20190606121238.zxdvvogob3umzid4@paasikivi.fi.intel.com> References: <1559555971-193235-1-git-send-email-vishal.sagar@xilinx.com> <1559555971-193235-2-git-send-email-vishal.sagar@xilinx.com> <20190604192344.7tycwffjd3yeizxh@paasikivi.fi.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: 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 Vishal, On Thu, Jun 06, 2019 at 11:54:19AM +0000, Vishal Sagar wrote: > Hi Sakari, > > > -----Original Message----- > > From: Sakari Ailus [mailto:sakari.ailus@linux.intel.com] > > Sent: Wednesday, June 05, 2019 12:54 AM > > To: Vishal Sagar > > Cc: Hyun Kwon ; laurent.pinchart@ideasonboard.com; > > mchehab@kernel.org; robh+dt@kernel.org; mark.rutland@arm.com; Michal > > Simek ; linux-media@vger.kernel.org; > > devicetree@vger.kernel.org; hans.verkuil@cisco.com; linux-arm- > > kernel@lists.infradead.org; linux-kernel@vger.kernel.org; Dinesh Kumar > > ; Sandip Kothari ; Luca Ceresoli > > ; Jacopo Mondi > > Subject: Re: [PATCH v8 1/2] media: dt-bindings: media: xilinx: Add Xilinx MIPI > > CSI-2 Rx Subsystem > > > > EXTERNAL EMAIL > > > > Hi Vishal, > > > > On Mon, Jun 03, 2019 at 03:29:30PM +0530, Vishal Sagar wrote: > > > > > +Optional properties: > > > +-------------------- > > > +- . > > > + Without this property the driver won't be loaded as IP won't be able to > > generate > > > + media bus format compliant stream output. > > > > I think we previously concluded that the format will be just different in > > this case. So the description appears incorrect. > > > > Referring to your email https://lkml.org/lkml/2019/3/22/1823 in response to v6 patches, > if the video format bridge is not enabled, then the way in which pixels are transported on > the bus don't correspond to the existing media bus formats in Linux. > > If not loading the driver is incorrect way, is it ok for the driver to allow same media bus format > for packed and unpacked data type on the sink pad? > > Or is it ok for the driver to not validate the media bus format set on the sink pad? Taking a fresh look at the issue --- usually such unpacking is done by the DMA engine, or the same device contains both the CSI-2 RX and DMA. But here it actually affects the input of that DMA engine. You're right in saying we don't have format definitions from which you could tell which case it is, and we also don't have other pre-existing means to tell them apart. Feel free to keep the check in the driver, but we can't refer to the driver loading in DT binding documentation: this is really not supposed to be related to that driver, or even Linux at all. How about changing this to: xlnx,vfb: Present when Video Format Bridge is enabled in IP configuration. That'd be aligned with the other properties and would more accurately convey what this means. -- Kind regards, Sakari Ailus sakari.ailus@linux.intel.com