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=-20.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT 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 AB717C433FE for ; Mon, 20 Sep 2021 17:58:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 92DB16187D for ; Mon, 20 Sep 2021 17:58:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1356466AbhITSAO (ORCPT ); Mon, 20 Sep 2021 14:00:14 -0400 Received: from mail.kernel.org ([198.145.29.99]:55426 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1355153AbhITRyP (ORCPT ); Mon, 20 Sep 2021 13:54:15 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id A85F061BFC; Mon, 20 Sep 2021 17:13:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1632158001; bh=sQw9MZjQniyUBF22K2BBv1mR9r1y/Ody4+hAHNxdgZQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=uCPgTHT6RJY/h2pYJak2yqTHlhbOCNk9Kp+NBipcE4ibXT+WRZtbEe6kgq3c17ZMS DGOt7Pd/W2DLQ1Cxr+MhZ+Ls2q/yZTf1LYCsTHStFLOPS9cZS7VtJDMkRUAyZuWmpi k5Pu6TebxQbhH/nZ8jwzQViHbF81yWSZbwobxJuA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Umang Jain , Laurent Pinchart , Dave Stevenson , Sakari Ailus , Mauro Carvalho Chehab , Sasha Levin Subject: [PATCH 4.19 207/293] media: imx258: Limit the max analogue gain to 480 Date: Mon, 20 Sep 2021 18:42:49 +0200 Message-Id: <20210920163940.354918549@linuxfoundation.org> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20210920163933.258815435@linuxfoundation.org> References: <20210920163933.258815435@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: Umang Jain [ Upstream commit f809665ee75fff3f4ea8907f406a66d380aeb184 ] The range for analog gain mentioned in the datasheet is [0, 480]. The real gain formula mentioned in the datasheet is: Gain = 512 / (512 – X) Hence, values larger than 511 clearly makes no sense. The gain register field is also documented to be of 9-bits in the datasheet. Certainly, it is enough to infer that, the kernel driver currently advertises an arbitrary analog gain max. Fix it by rectifying the value as per the data sheet i.e. 480. Signed-off-by: Umang Jain Reviewed-by: Laurent Pinchart Reviewed-by: Dave Stevenson Signed-off-by: Sakari Ailus Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Sasha Levin --- drivers/media/i2c/imx258.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/media/i2c/imx258.c b/drivers/media/i2c/imx258.c index 68ce63333744..85395813c0f2 100644 --- a/drivers/media/i2c/imx258.c +++ b/drivers/media/i2c/imx258.c @@ -46,7 +46,7 @@ /* Analog gain control */ #define IMX258_REG_ANALOG_GAIN 0x0204 #define IMX258_ANA_GAIN_MIN 0 -#define IMX258_ANA_GAIN_MAX 0x1fff +#define IMX258_ANA_GAIN_MAX 480 #define IMX258_ANA_GAIN_STEP 1 #define IMX258_ANA_GAIN_DEFAULT 0x0 -- 2.30.2