Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E9D2FC433EF for ; Wed, 24 Nov 2021 12:17:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243481AbhKXMUd (ORCPT ); Wed, 24 Nov 2021 07:20:33 -0500 Received: from mail.kernel.org ([198.145.29.99]:39084 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243713AbhKXMPP (ORCPT ); Wed, 24 Nov 2021 07:15:15 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 8D6336109D; Wed, 24 Nov 2021 12:10:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1637755804; bh=vztLzOr4nWOxS4kqpPZSFPvpeLB5f0Thi1CD+HofyI8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=J8+rcEyc7iZuCoVoGNk/aDQfGxHSYQD0dryjj57nU0jWuYHtg0kA8jfJ8KHZfdDDa RmXkU/hdG4LJkUcvtGi22QrNV3w1EqaFilI8ArGeb2kJ56yNMvPv6azXNCekgNlLd/ qArkdj5w7aTFOlbEhwiE1ivfel7rQf+zdM+/kU7g= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dirk Bender , Stefan Riedmueller , Sakari Ailus , Mauro Carvalho Chehab , Sasha Levin Subject: [PATCH 4.9 064/207] media: mt9p031: Fix corrupted frame after restarting stream Date: Wed, 24 Nov 2021 12:55:35 +0100 Message-Id: <20211124115705.996858744@linuxfoundation.org> X-Mailer: git-send-email 2.34.0 In-Reply-To: <20211124115703.941380739@linuxfoundation.org> References: <20211124115703.941380739@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Dirk Bender [ Upstream commit 0961ba6dd211a4a52d1dd4c2d59be60ac2dc08c7 ] To prevent corrupted frames after starting and stopping the sensor its datasheet specifies a specific pause sequence to follow: Stopping: Set Pause_Restart Bit -> Set Restart Bit -> Set Chip_Enable Off Restarting: Set Chip_Enable On -> Clear Pause_Restart Bit The Restart Bit is cleared automatically and must not be cleared manually as this would cause undefined behavior. Signed-off-by: Dirk Bender Signed-off-by: Stefan Riedmueller Signed-off-by: Sakari Ailus Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Sasha Levin --- drivers/media/i2c/mt9p031.c | 28 +++++++++++++++++++++++++++- 1 file changed, 27 insertions(+), 1 deletion(-) diff --git a/drivers/media/i2c/mt9p031.c b/drivers/media/i2c/mt9p031.c index 237737fec09c1..e6159faff45af 100644 --- a/drivers/media/i2c/mt9p031.c +++ b/drivers/media/i2c/mt9p031.c @@ -81,7 +81,9 @@ #define MT9P031_PIXEL_CLOCK_INVERT (1 << 15) #define MT9P031_PIXEL_CLOCK_SHIFT(n) ((n) << 8) #define MT9P031_PIXEL_CLOCK_DIVIDE(n) ((n) << 0) -#define MT9P031_FRAME_RESTART 0x0b +#define MT9P031_RESTART 0x0b +#define MT9P031_FRAME_PAUSE_RESTART (1 << 1) +#define MT9P031_FRAME_RESTART (1 << 0) #define MT9P031_SHUTTER_DELAY 0x0c #define MT9P031_RST 0x0d #define MT9P031_RST_ENABLE 1 @@ -448,9 +450,23 @@ static int mt9p031_set_params(struct mt9p031 *mt9p031) static int mt9p031_s_stream(struct v4l2_subdev *subdev, int enable) { struct mt9p031 *mt9p031 = to_mt9p031(subdev); + struct i2c_client *client = v4l2_get_subdevdata(subdev); + int val; int ret; if (!enable) { + /* enable pause restart */ + val = MT9P031_FRAME_PAUSE_RESTART; + ret = mt9p031_write(client, MT9P031_RESTART, val); + if (ret < 0) + return ret; + + /* enable restart + keep pause restart set */ + val |= MT9P031_FRAME_RESTART; + ret = mt9p031_write(client, MT9P031_RESTART, val); + if (ret < 0) + return ret; + /* Stop sensor readout */ ret = mt9p031_set_output_control(mt9p031, MT9P031_OUTPUT_CONTROL_CEN, 0); @@ -470,6 +486,16 @@ static int mt9p031_s_stream(struct v4l2_subdev *subdev, int enable) if (ret < 0) return ret; + /* + * - clear pause restart + * - don't clear restart as clearing restart manually can cause + * undefined behavior + */ + val = MT9P031_FRAME_RESTART; + ret = mt9p031_write(client, MT9P031_RESTART, val); + if (ret < 0) + return ret; + return mt9p031_pll_enable(mt9p031); } -- 2.33.0