From patchwork Tue Jul 26 12:05:50 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andy Shevchenko X-Patchwork-Id: 12929214 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 1A75DCCA47E for ; Tue, 26 Jul 2022 12:05:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239024AbiGZMF4 (ORCPT ); Tue, 26 Jul 2022 08:05:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46198 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232678AbiGZMFz (ORCPT ); Tue, 26 Jul 2022 08:05:55 -0400 Received: from mga12.intel.com (mga12.intel.com [192.55.52.136]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9D7F714008; Tue, 26 Jul 2022 05:05:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1658837154; x=1690373154; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=jMC2wNGyqJFQfBamjOwEaaiV4YpyT3KOmIURe2y6h6U=; b=X8AmgrsL3mix3YyCOk3YocMksYLpgJ05+peM1yymXF8ccswIHE3cTIGe L95njfrNpIgTbPdWC2rA6akUYT1wQqihKGwVwfFnUeIuZEtpWG98u70yp Al3/soEYF48RYPEvpR9jJS4bS64lOJ1bfDhQ7TxaiLUTlo2tQ4N5I4Sqb W8gLIf04Fbwf9Dkr2pcRkD5v7du85ZIiJM3dPDEAdR4lRaIbKp05zJWrd RknMDML3J9zAa/rm7Qz9WiPHmggC5NtBL4FECQyfGOdbrq/TSro5TruVE PZkEfiZih7v9ksvJtUneRQ/z08Y8Jw4cOLGnsCkCvcGmXLUeM3RT6oqca g==; X-IronPort-AV: E=McAfee;i="6400,9594,10419"; a="267703529" X-IronPort-AV: E=Sophos;i="5.93,193,1654585200"; d="scan'208";a="267703529" Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 Jul 2022 05:05:54 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.93,193,1654585200"; d="scan'208";a="845854992" Received: from black.fi.intel.com ([10.237.72.28]) by fmsmga006.fm.intel.com with ESMTP; 26 Jul 2022 05:05:52 -0700 Received: by black.fi.intel.com (Postfix, from userid 1003) id 5DBAB86; Tue, 26 Jul 2022 15:06:02 +0300 (EEST) From: Andy Shevchenko To: Andy Shevchenko , linux-media@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Tianshu Qiu , Shawn Tu , Bingbu Cao , Mauro Carvalho Chehab Subject: [PATCH v1 2/8] media: ov2740: Replace voodoo coding with understandle flow Date: Tue, 26 Jul 2022 15:05:50 +0300 Message-Id: <20220726120556.2881-2-andriy.shevchenko@linux.intel.com> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220726120556.2881-1-andriy.shevchenko@linux.intel.com> References: <20220726120556.2881-1-andriy.shevchenko@linux.intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org Besides not being understandable at the first glance, the code might provoke a compiler or a static analyser tool to warn about out-of-bound access (when len == 0). Replace it with clear flow an understandable intention. Signed-off-by: Andy Shevchenko Reviewed-by: Bingbu Cao --- drivers/media/i2c/ov2740.c | 28 +++++++++++++++++++++++----- 1 file changed, 23 insertions(+), 5 deletions(-) diff --git a/drivers/media/i2c/ov2740.c b/drivers/media/i2c/ov2740.c index c975db1bbe8c..81c0ab220339 100644 --- a/drivers/media/i2c/ov2740.c +++ b/drivers/media/i2c/ov2740.c @@ -377,10 +377,10 @@ static int ov2740_read_reg(struct ov2740 *ov2740, u16 reg, u16 len, u32 *val) struct i2c_client *client = v4l2_get_subdevdata(&ov2740->sd); struct i2c_msg msgs[2]; u8 addr_buf[2]; - u8 data_buf[4] = {0}; + u8 data_buf[4]; int ret = 0; - if (len > sizeof(data_buf)) + if (len > 4) return -EINVAL; put_unaligned_be16(reg, addr_buf); @@ -391,13 +391,22 @@ static int ov2740_read_reg(struct ov2740 *ov2740, u16 reg, u16 len, u32 *val) msgs[1].addr = client->addr; msgs[1].flags = I2C_M_RD; msgs[1].len = len; - msgs[1].buf = &data_buf[sizeof(data_buf) - len]; + msgs[1].buf = data_buf; ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs)); if (ret != ARRAY_SIZE(msgs)) return ret < 0 ? ret : -EIO; - *val = get_unaligned_be32(data_buf); + if (len == 4) + *val = get_unaligned_be32(data_buf); + else if (len == 3) + *val = get_unaligned_be24(data_buf); + else if (len == 2) + *val = get_unaligned_be16(data_buf); + else if (len == 1) + *val = data_buf[0]; + else + return -EINVAL; return 0; } @@ -412,7 +421,16 @@ static int ov2740_write_reg(struct ov2740 *ov2740, u16 reg, u16 len, u32 val) return -EINVAL; put_unaligned_be16(reg, buf); - put_unaligned_be32(val << 8 * (4 - len), buf + 2); + if (len == 4) + put_unaligned_be32(val, buf + 2); + else if (len == 3) + put_unaligned_be24(val, buf + 2); + else if (len == 2) + put_unaligned_be16(val, buf + 2); + else if (len == 1) + buf[2] = val; + else + return -EINVAL; ret = i2c_master_send(client, buf, len + 2); if (ret != len + 2)