From patchwork Thu Sep 16 16:00:05 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 513681 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=-19.1 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=ham 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 7B641C433F5 for ; Thu, 16 Sep 2021 17:29:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 65DE06108F for ; Thu, 16 Sep 2021 17:29:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347291AbhIPRbJ (ORCPT ); Thu, 16 Sep 2021 13:31:09 -0400 Received: from mail.kernel.org ([198.145.29.99]:47066 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1352809AbhIPR2l (ORCPT ); Thu, 16 Sep 2021 13:28:41 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 27DCD61C48; Thu, 16 Sep 2021 16:45:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1631810757; bh=FkXCrBHyxq0hGuRyOSF1iQfp1/fAS0OjE1l6GxYEsVo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=crJaHvOVp+3nfmjU7lejX+P0NaoyOjgQe0V3jVg3GNsR64fzl9G6/L42RHi6PwvM4 Y6/9hdK4+KNTleQiJgGMYGL0faIC/7fP2+yIPWqbEUmthNb9ocDU1trvOBpiKUtpf6 bilVDBU7C/PvOyk0XnuIH8Kpe4OLHaIozOujzWmE= 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 5.14 256/432] media: imx258: Limit the max analogue gain to 480 Date: Thu, 16 Sep 2021 18:00:05 +0200 Message-Id: <20210916155819.500380422@linuxfoundation.org> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20210916155810.813340753@linuxfoundation.org> References: <20210916155810.813340753@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@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 4e695096e5d0..81cdf37216ca 100644 --- a/drivers/media/i2c/imx258.c +++ b/drivers/media/i2c/imx258.c @@ -47,7 +47,7 @@ /* 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