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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 80894C4CEC9 for ; Fri, 20 Sep 2019 14:36:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 63638205F4 for ; Fri, 20 Sep 2019 14:36:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391894AbfITOgJ (ORCPT ); Fri, 20 Sep 2019 10:36:09 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:35858 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388063AbfITOZB (ORCPT ); Fri, 20 Sep 2019 10:25:01 -0400 Received: from [192.168.4.242] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1iBJqE-0004xy-Pd; Fri, 20 Sep 2019 15:24:58 +0100 Received: from ben by deadeye with local (Exim 4.92.1) (envelope-from ) id 1iBJqD-0007rl-I0; Fri, 20 Sep 2019 15:24:57 +0100 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, Denis Kirjanov , "Janusz Krzysztofik" , "Mauro Carvalho Chehab" , "Sakari Ailus" Date: Fri, 20 Sep 2019 15:23:35 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 040/132] media: ov6650: Fix sensor possibly not detected on probe In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.242 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.74-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Janusz Krzysztofik commit 933c1320847f5ed6b61a7d10f0a948aa98ccd7b0 upstream. After removal of clock_start() from before soc_camera_init_i2c() in soc_camera_probe() by commit 9aea470b399d ("[media] soc-camera: switch I2C subdevice drivers to use v4l2-clk") introduced in v3.11, the ov6650 driver could no longer probe the sensor successfully because its clock was no longer turned on in advance. The issue was initially worked around by adding that missing clock_start() equivalent to OMAP1 camera interface driver - the only user of this sensor - but a propoer fix should be rather implemented in the sensor driver code itself. Fix the issue by inserting a delay between the clock is turned on and the sensor I2C registers are read for the first time. Tested on Amstrad Delta with now out of tree but still locally maintained omap1_camera host driver. Fixes: 9aea470b399d ("[media] soc-camera: switch I2C subdevice drivers to use v4l2-clk") Signed-off-by: Janusz Krzysztofik Signed-off-by: Sakari Ailus Signed-off-by: Mauro Carvalho Chehab [bwh: Backported to 3.16: adjust filename] Signed-off-by: Ben Hutchings --- drivers/media/i2c/soc_camera/ov6650.c | 2 ++ 1 file changed, 2 insertions(+) --- a/drivers/media/i2c/soc_camera/ov6650.c +++ b/drivers/media/i2c/soc_camera/ov6650.c @@ -829,6 +829,8 @@ static int ov6650_video_probe(struct i2c if (ret < 0) return ret; + msleep(20); + /* * check and show product ID and manufacturer ID */