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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 9FFF4C5AE59 for ; Wed, 4 Jun 2025 03:19:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=3ipajgpO2E0wbo1COI5kY80gkX4K9BchvND4TO26YqY=; b=DMLltTcqrwIGco88BTyQPFSR7S rW9+nA8cNZbEP8vZyrTe1qiFieYpFL88yiRuXHlwqlIHVOsY20fpjx+anE8NoDhvK+0vzinwvLjIK Z011m7i0tQsQKNz7fnPR6u6uSpvutYHN1Ou9z+vuRBFmMnpw6uCSnIBxdPGhoKmdxmf4CKt8i9ld4 mc63q9oEMRvqsFM/9YdchoITDqVgOM9YMK2zq1Mm5F8yZb7Ay+utV3wqoCIkl1Cp4VbBWHA9o4LGH LW5ZrIIyEaPrMQ9mnEYDZT/fwk4yXj30994ogMldAvKeya7Ud6aUIQaeddIt3HErVlij7SwRHbdzY gv9yXmKQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1uMef6-0000000CQVL-2F9t; Wed, 04 Jun 2025 03:19:32 +0000 Received: from sea.source.kernel.org ([172.234.252.31]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1uMcZl-0000000C8xs-3Ata for linux-arm-kernel@lists.infradead.org; Wed, 04 Jun 2025 01:05:54 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id 6B82243C8F; Wed, 4 Jun 2025 01:05:53 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 03AF5C4CEEF; Wed, 4 Jun 2025 01:05:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1748999153; bh=/WVBA9vVoqr5pvHpJJLpmh960vJBV0Kw2Rc3nHzB+kI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=XYvYQASjvw0PRBJXJs+trG94davdORBs+8XOIscfPtM6Hc28ann2KslnWXbYc5D3c DhlDnJqOd1cPZ3k9EseVmAQ594t6KwDHFG8AY/TVvmzW0ZajQ50ofBrKgszRqsS2Rf GwULtXQk+cJoYy5h6yOeumDWEnqGHX/Fv/wKBQDBHR0Bt1Un0YaRYdgAGNYj8yy7N2 UR7WIiTff8940qFbh103JXnjkoy15FjRZBLVMOwpp2ZtvecolFfq6TgR+J8iIXeIIU iVBMB+dx/no1JVD6lzC5fTF/kYADaDlAyDRdfZYmaYHprAjqt3Cdk129oBo4I/wAs/ uWJ+t0Ba2UFyA== From: Sasha Levin To: patches@lists.linux.dev, stable@vger.kernel.org Cc: Gabor Juhos , Imre Kaloz , Andrew Lunn , Linus Walleij , Sasha Levin , gregory.clement@bootlin.com, sebastian.hesselbarth@gmail.com, brgl@bgdev.pl, linux-arm-kernel@lists.infradead.org, linux-gpio@vger.kernel.org Subject: [PATCH AUTOSEL 5.15 16/33] pinctrl: armada-37xx: propagate error from armada_37xx_gpio_get_direction() Date: Tue, 3 Jun 2025 21:05:07 -0400 Message-Id: <20250604010524.6091-16-sashal@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250604010524.6091-1-sashal@kernel.org> References: <20250604010524.6091-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 5.15.184 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250603_180553_842666_AFBEAD0C X-CRM114-Status: GOOD ( 18.17 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org From: Gabor Juhos [ Upstream commit 6481c0a83367b0672951ccc876fbae7ee37b594b ] The regmap_read() function can fail, so propagate its error up to the stack instead of silently ignoring that. Signed-off-by: Imre Kaloz Reviewed-by: Andrew Lunn Signed-off-by: Gabor Juhos Link: https://lore.kernel.org/20250514-pinctrl-a37xx-fixes-v2-6-07e9ac1ab737@gmail.com Signed-off-by: Linus Walleij Signed-off-by: Sasha Levin --- Based on my analysis, let me provide my assessment: **YES** This commit should be backported to stable kernel trees. **Detailed Analysis:** 1. **Bug Fix Nature**: This commit addresses a real bug where `regmap_read()` errors are silently ignored in `armada_37xx_gpio_get_direction()`. The function signature shows it returns `int`, indicating it can fail and return error codes. 2. **Error Propagation Pattern**: Looking at similar drivers (e.g., `/home/sasha/linux/drivers/pinctrl/meson/pinctrl-amlogic-a4.c`), the standard pattern is: ```c ret = regmap_read(bank->reg_gpio, reg, &val); if (ret) return ret; ``` This commit follows the exact same pattern, which is the correct approach. 3. **Critical Function**: The `armada_37xx_gpio_get_direction()` function is part of the GPIO subsystem API that userspace and kernel code rely on. If `regmap_read()` fails (due to hardware issues, power management states, etc.), the function currently returns a potentially garbage direction value, which could lead to: - Incorrect GPIO configuration - Silent hardware access failures - Potential system instability 4. **Small and Contained Change**: The fix is minimal: - Adds error checking for `regmap_read()` - Propagates the error up the stack - No architectural changes - No new features introduced 5. **Low Risk**: This change has minimal regression risk because: - It only affects error paths that were previously ignored - Normal operation (when regmap_read succeeds) is unchanged - It follows established patterns in the same subsystem 6. **Similar Historical Commits**: Looking at the provided examples, this aligns with commits marked as "Backport Status: YES": - Similar Commit #2 fixed direction_output callback behavior with error handling - The pattern of adding proper error propagation is common in stable backports 7. **Hardware Impact**: The Armada 37xx pinctrl driver is used in real hardware (Marvell Armada 3700 SoCs), so fixing silent error conditions improves reliability for users. 8. **Stable Criteria Compliance**: This commit meets stable tree criteria: - Fixes a real bug (silent error handling) - Small, contained change - No feature additions - Improves system reliability The commit properly addresses a silent failure mode in a hardware interface, making it a good candidate for stable backporting to ensure system reliability across kernel versions. drivers/pinctrl/mvebu/pinctrl-armada-37xx.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/pinctrl/mvebu/pinctrl-armada-37xx.c b/drivers/pinctrl/mvebu/pinctrl-armada-37xx.c index 46cccd72b4ddd..2a9afe828f484 100644 --- a/drivers/pinctrl/mvebu/pinctrl-armada-37xx.c +++ b/drivers/pinctrl/mvebu/pinctrl-armada-37xx.c @@ -396,10 +396,13 @@ static int armada_37xx_gpio_get_direction(struct gpio_chip *chip, struct armada_37xx_pinctrl *info = gpiochip_get_data(chip); unsigned int reg = OUTPUT_EN; unsigned int val, mask; + int ret; armada_37xx_update_reg(®, &offset); mask = BIT(offset); - regmap_read(info->regmap, reg, &val); + ret = regmap_read(info->regmap, reg, &val); + if (ret) + return ret; if (val & mask) return GPIO_LINE_DIRECTION_OUT; -- 2.39.5