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=-2.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 397E1C35280 for ; Wed, 2 Oct 2019 12:12:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 076A6218DE for ; Wed, 2 Oct 2019 12:12:41 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ti.com header.i=@ti.com header.b="F0ZBUFy8" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726396AbfJBMMk (ORCPT ); Wed, 2 Oct 2019 08:12:40 -0400 Received: from lelv0143.ext.ti.com ([198.47.23.248]:35762 "EHLO lelv0143.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725766AbfJBMMj (ORCPT ); Wed, 2 Oct 2019 08:12:39 -0400 Received: from fllv0034.itg.ti.com ([10.64.40.246]) by lelv0143.ext.ti.com (8.15.2/8.15.2) with ESMTP id x92CCRQs082861; Wed, 2 Oct 2019 07:12:27 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1570018347; bh=BY8geDIzMt6+Ioryuldlxg8hyLYttBQCYwF+MAIrCvQ=; h=Date:From:To:CC:Subject:References:In-Reply-To; b=F0ZBUFy8/WJo8ehdXp3ee1h6ElZ5waQIoVQBnQL8DibGXbGEEjmsyEM+1R+0rHh5H 8qpzS3UL+wLIslPqMA6GvgMmd8W+pNWBgaSmh8Tb5nMtcixzsbcp7D28Iz+wC8vCSD dzVSUFrgor02Mso2bB50ti1sBqh8xZ7qh3RRR4GY= Received: from DFLE109.ent.ti.com (dfle109.ent.ti.com [10.64.6.30]) by fllv0034.itg.ti.com (8.15.2/8.15.2) with ESMTPS id x92CCRxR078079 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Wed, 2 Oct 2019 07:12:27 -0500 Received: from DFLE114.ent.ti.com (10.64.6.35) by DFLE109.ent.ti.com (10.64.6.30) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1713.5; Wed, 2 Oct 2019 07:12:16 -0500 Received: from fllv0039.itg.ti.com (10.64.41.19) by DFLE114.ent.ti.com (10.64.6.35) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1713.5 via Frontend Transport; Wed, 2 Oct 2019 07:12:27 -0500 Received: from ti.com (ileax41-snat.itg.ti.com [10.172.224.153]) by fllv0039.itg.ti.com (8.15.2/8.15.2) with SMTP id x92CCRVp014399; Wed, 2 Oct 2019 07:12:27 -0500 Date: Wed, 2 Oct 2019 07:14:38 -0500 From: Benoit Parrot To: Jacopo Mondi CC: Sakari Ailus , Hans Verkuil , , , , Subject: Re: [Patch 1/3] media: ov5640: add PIXEL_RATE control Message-ID: <20191002121438.g3re6v54q4hit2wv@ti.com> References: <20190925152301.21645-1-bparrot@ti.com> <20190925152301.21645-2-bparrot@ti.com> <20191001075704.GA5449@paasikivi.fi.intel.com> <20191001162341.f2o7ruar2nifl5ws@ti.com> <20191002075951.afp2xligspqat4ew@uno.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <20191002075951.afp2xligspqat4ew@uno.localdomain> User-Agent: NeoMutt/20171215 X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Jacopo, Maybe, I miss spoke when I mentioned a helper I did not intent a framework level generic function. Just a function to help in this case :) That being said, I re-read the thread you mentioned. And as Hughes pointed out dynamically generating a "working" link frequency value which can be used by a CSI2 receiver to properly configure its PHY is not trivial. When I created this patch, I also had another to add V4L2_CID_LINK_FREQ support. I am testing this against the TI CAL CSI2 receiver, which already uses the V4L2_CID_PIXEL_RATE value for that purpose, so I also had a patch to add support for V4L2_CID_LINK_FREQ to that driver as well. Unfortunately, similar to Hughes' findings I was not able to make it "work" with all supported resolution/framerate. Unlike my V4L2_CID_PIXEL_RATE solution which now works in all mode with the same receiver. So long story short I dropped the V4L2_CID_LINK_FREQ patch and focused on V4L2_CID_PIXEL_RATE instead. Regard, Benoit Jacopo Mondi wrote on Wed [2019-Oct-02 09:59:51 +0200]: > Hi Benoit, > +Hugues > > If you're considering an helper, this thread might be useful to you: > https://patchwork.kernel.org/patch/11019673/ > > Thanks > j >