From nobody Fri Dec 19 21:47:30 2025 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 3607D18E74E; Wed, 13 Mar 2024 16:48:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710348484; cv=none; b=EPPqrUXg+XCpUFQIkeXz2snUAaaHHgSn1Xyp6a9ZBIi1+vLrStfAJ08uS2JaRAKCUotpMGlcG5H+dOCMVNKKyOVshM5mUXuOFgE/OzWYUB8O04CAae+RWjaJVwUXQrQnGhV8HSIk318KoIBU6wLZDRfWAVQgwKzVPxOOIbL2x28= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710348484; c=relaxed/simple; bh=bN6FyHWve+cJ69LrHSPDI7ih6sH5X6u68hczeQ7NoUs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=FaO29euk0dDugUDLH9mS6n8a03wyZyGycSuOr0EO89yzqS086Esmew6/YZ3H+VWYVLuMRnQFLkg/n8XpA4+K8u4yZ/dCHXXLeVn5MDgr7zXEMIBFoSf69Uye2I4qE4IrIOOGWIGyyyXKpWVSK2JCo7MlWBPhll8fmsr7mVBrMpo= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Dlnh8GXf; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Dlnh8GXf" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DDB12C433C7; Wed, 13 Mar 2024 16:48:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1710348483; bh=bN6FyHWve+cJ69LrHSPDI7ih6sH5X6u68hczeQ7NoUs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Dlnh8GXfKm3qMIorABkpoGP/gpEYSTIzUMNJm7HcnxQGSgUnxIm1T+Nzve5e8uoVD Zny+2tCeKq0xgZsBDqOZd5c0OADfNUCo+4elmZXO7t2iEKuAKa39Z7kAb2BG376yUj KbsUTFarJHDlVJqiuIlWjaF5XsQwWPHV6ZecB7IKn9teIDsTse8OSHqxxsR68qhlas hkh+E6jHbTPPfWT9J2j8g0oW+WYlI0ciqWx83lyiiwB0XoIUgyqXNPJH4TCV48srSM cdmZEfJzX/oUQA0qvU1MtnW1DzTqxTW0Kz7nrfEhfB7/7wHtdZn2pGLOQCTY29w2KD q3HAv+dh2surg== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: =?UTF-8?q?Jan=20Kundr=C3=A1t?= , Andy Shevchenko , Greg Kroah-Hartman , Sasha Levin Subject: [PATCH 5.10 72/73] serial: max310x: fix IO data corruption in batched operations Date: Wed, 13 Mar 2024 12:46:39 -0400 Message-ID: <20240313164640.616049-73-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240313164640.616049-1-sashal@kernel.org> References: <20240313164640.616049-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" X-KernelTest-Patch: http://kernel.org/pub/linux/kernel/v5.x/stable-review/patch-5.10.213-rc1.gz X-KernelTest-Tree: git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git X-KernelTest-Branch: linux-5.10.y X-KernelTest-Patches: git://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git X-KernelTest-Version: 5.10.213-rc1 X-KernelTest-Deadline: 2024-03-15T16:46+00:00 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: quoted-printable From: Jan Kundr=C3=A1t [ Upstream commit 3f42b142ea1171967e40e10e4b0241c0d6d28d41 ] After upgrading from 5.16 to 6.1, our board with a MAX14830 started producing lots of garbage data over UART. Bisection pointed out commit 285e76fc049c as the culprit. That patch tried to replace hand-written code which I added in 2b4bac48c1084 ("serial: max310x: Use batched reads when reasonably safe") with the generic regmap infrastructure for batched operations. Unfortunately, the `regmap_raw_read` and `regmap_raw_write` which were used are actually functions which perform IO over *multiple* registers. That's not what is needed for accessing these Tx/Rx FIFOs; the appropriate functions are the `_noinc_` versions, not the `_raw_` ones. Fix this regression by using `regmap_noinc_read()` and `regmap_noinc_write()` along with the necessary `regmap_config` setup; with this patch in place, our board communicates happily again. Since our board uses SPI for talking to this chip, the I2C part is completely untested. Fixes: 285e76fc049c ("serial: max310x: use regmap methods for SPI batch ope= rations") Cc: stable@vger.kernel.org Reviewed-by: Andy Shevchenko Signed-off-by: Jan Kundr=C3=A1t Link: https://lore.kernel.org/r/79db8e82aadb0e174bc82b9996423c3503c8fb37.16= 80732084.git.jan.kundrat@cesnet.cz Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/tty/serial/max310x.c | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-) diff --git a/drivers/tty/serial/max310x.c b/drivers/tty/serial/max310x.c index ed1aaa19854fd..2f88eae8a55a1 100644 --- a/drivers/tty/serial/max310x.c +++ b/drivers/tty/serial/max310x.c @@ -533,6 +533,11 @@ static bool max310x_reg_precious(struct device *dev, u= nsigned int reg) return false; } =20 +static bool max310x_reg_noinc(struct device *dev, unsigned int reg) +{ + return reg =3D=3D MAX310X_RHR_REG; +} + static int max310x_set_baud(struct uart_port *port, int baud) { unsigned int mode =3D 0, div =3D 0, frac =3D 0, c =3D 0, F =3D 0; @@ -667,14 +672,14 @@ static void max310x_batch_write(struct uart_port *por= t, u8 *txbuf, unsigned int { struct max310x_one *one =3D to_max310x_port(port); =20 - regmap_raw_write(one->regmap, MAX310X_THR_REG, txbuf, len); + regmap_noinc_write(one->regmap, MAX310X_THR_REG, txbuf, len); } =20 static void max310x_batch_read(struct uart_port *port, u8 *rxbuf, unsigned= int len) { struct max310x_one *one =3D to_max310x_port(port); =20 - regmap_raw_read(one->regmap, MAX310X_RHR_REG, rxbuf, len); + regmap_noinc_read(one->regmap, MAX310X_RHR_REG, rxbuf, len); } =20 static void max310x_handle_rx(struct uart_port *port, unsigned int rxlen) @@ -1508,6 +1513,10 @@ static struct regmap_config regcfg =3D { .writeable_reg =3D max310x_reg_writeable, .volatile_reg =3D max310x_reg_volatile, .precious_reg =3D max310x_reg_precious, + .writeable_noinc_reg =3D max310x_reg_noinc, + .readable_noinc_reg =3D max310x_reg_noinc, + .max_raw_read =3D MAX310X_FIFO_SIZE, + .max_raw_write =3D MAX310X_FIFO_SIZE, }; =20 #ifdef CONFIG_SPI_MASTER @@ -1593,6 +1602,10 @@ static struct regmap_config regcfg_i2c =3D { .volatile_reg =3D max310x_reg_volatile, .precious_reg =3D max310x_reg_precious, .max_register =3D MAX310X_I2C_REVID_EXTREG, + .writeable_noinc_reg =3D max310x_reg_noinc, + .readable_noinc_reg =3D max310x_reg_noinc, + .max_raw_read =3D MAX310X_FIFO_SIZE, + .max_raw_write =3D MAX310X_FIFO_SIZE, }; =20 static const struct max310x_if_cfg max310x_i2c_if_cfg =3D { --=20 2.43.0