From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1E31720F4 for ; Fri, 13 May 2022 04:42:01 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D4C95C34116; Fri, 13 May 2022 04:41:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1652416920; bh=yRw9OiL6/COzMbaUd1gNsGDfBq6AJMmRuleh8yX3C5M=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=GqIF3uqEkBLQ3TqFsbwTTgRGpIyF7/KDTGwosK+byp6hSagAFgp4s0MP9in50ccTm sjdUhU+S4fW8TsFn5+Rg55jLn0XQwWRoHoYZ8sT11LOlF5Dd+daJz+vGVHZjMmgVWC Ui6jQZzxfYW5hCqDU1whSil7XFrTahP7BOh3+y9k/QhF2YOd0mSVYeCEs6fjyGmOGj aVNTV2VaQqtVZv7pdvgFIVYdCoViZJ0ZY73CFlXYa1re6QelzEFXA+kB+AoHPfDDpi +EUywEYuHp4Eb1n/elCATQhLElPINYkQjyDVqx01i+qdLhICN3KSQsY+UhiG0g97OL BP6KqbMxayluA== From: Tzung-Bi Shih To: bleung@chromium.org, groeck@chromium.org Cc: chrome-platform@lists.linux.dev, tzungbi@kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 6/7] platform/chrome: cros_ec_spi: drop unneeded BUG_ON() Date: Fri, 13 May 2022 12:41:42 +0800 Message-Id: <20220513044143.1045728-7-tzungbi@kernel.org> X-Mailer: git-send-email 2.36.0.550.gb090851708-goog In-Reply-To: <20220513044143.1045728-1-tzungbi@kernel.org> References: <20220513044143.1045728-1-tzungbi@kernel.org> Precedence: bulk X-Mailing-List: chrome-platform@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit In the context, the following conditions are always false: - `todo` < 0 Suppose that EC_SPI_FRAME_START is found at the last byte of transfer. In the case, `ptr` == `end` - 1. As a result, `todo` must be 0. - `todo` > `ec_dev->din_size` Suppose that there is no preamble bytes. EC_SPI_FRAME_START is found at the first byte of transfer. In the case, `end` == `ptr` + EC_MSG_PREAMBLE_COUNT. As a result, `todo` == EC_MSG_PREAMBLE_COUNT - 1. However, it already checked `ec_dev->din_size` < EC_MSG_PREAMBLE_COUNT at the beginning of function. Drop the unneeded BUG_ON(). Signed-off-by: Tzung-Bi Shih --- Changes from v1: - Separate from the original 6th patch. - Drop the BUG_ON() instead of returning -EINVAL. drivers/platform/chrome/cros_ec_spi.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/drivers/platform/chrome/cros_ec_spi.c b/drivers/platform/chrome/cros_ec_spi.c index 589f18e9537d..5264615f46af 100644 --- a/drivers/platform/chrome/cros_ec_spi.c +++ b/drivers/platform/chrome/cros_ec_spi.c @@ -237,7 +237,6 @@ static int cros_ec_spi_receive_packet(struct cros_ec_device *ec_dev, * start of our buffer */ todo = end - ++ptr; - BUG_ON(todo < 0 || todo > ec_dev->din_size); todo = min(todo, need_len); memmove(ec_dev->din, ptr, todo); ptr = ec_dev->din + todo; @@ -345,7 +344,6 @@ static int cros_ec_spi_receive_response(struct cros_ec_device *ec_dev, * start of our buffer */ todo = end - ++ptr; - BUG_ON(todo < 0 || todo > ec_dev->din_size); todo = min(todo, need_len); memmove(ec_dev->din, ptr, todo); ptr = ec_dev->din + todo; -- 2.36.0.550.gb090851708-goog