From nobody Wed Dec 17 14:24:44 2025 Received: from gloria.sntech.de (gloria.sntech.de [185.11.138.130]) (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 1191A3385A9 for ; Thu, 13 Nov 2025 16:52:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.11.138.130 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763052748; cv=none; b=QdnkwnHGB1ZVddmKn9LHDYwifOIZzSi5ymsjE3asTfAJl6FjGyq1+Ncerzi5jslBwo/3nkJTBG8P7FadUzqn6p9ax/ulidu22EG4FKOyjTnId0NBen64BGDh/28WsjrFtcSHtYgu/2OPs3fkLtP4a7oP7YoipxtGLOrgeERmQ/8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763052748; c=relaxed/simple; bh=nXovU8Z9lcvw9h3dBvRi7sK4wfZTfh+iEEWHXqhJ3Zs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=afXFUgUp4t1SPlhzs+WnTRXv6eL3iKJJplKezjiIEsCsSMkaL6Eb0F+jb7mhZ6qN3Ho4ZlgNRXKyvTl2jdLwBTNQZBtFlBPgg0ZC2NRTVaGmDkl16DPihdXOz5cDIGplskbgxfYA2AB6fVLcXofaSzp7VN4nRez95cp5PHnukEU= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=sntech.de; spf=pass smtp.mailfrom=sntech.de; dkim=pass (2048-bit key) header.d=sntech.de header.i=@sntech.de header.b=tvTNLPAP; arc=none smtp.client-ip=185.11.138.130 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=sntech.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=sntech.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=sntech.de header.i=@sntech.de header.b="tvTNLPAP" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sntech.de; s=gloria202408; h=Content-Transfer-Encoding:MIME-Version:References: In-Reply-To:Message-ID:Date:Subject:Cc:To:From:Reply-To:Content-Type; bh=/P2H1HQIzFcvBqE1RaZPIVfxAOIj1n2GfQ8xkB+a48M=; b=tvTNLPAPRAq0BJdaE+HJT+L9pw Ku0nVR9uu97JNIQIiYotK9TcrmtzUgFkvQY2uBF0H1Umyf5nMLvpNdPlZ2Eyqce2rr7IYyz0K6mmV h/l2tUT8xVxxgG55Qkw5K+Ey2Pb04SrfG5RBKhGyB8Pb5XiJeow0wdcEvMY5yKtopxBftQ5DdjVkr 9bfgzJ4hEVCun9Km49wkzy3rTRIE35A35W97PBXL/34tqbOtQJdj3/FFKiKsIKipvoeR4BdlQ9srr n0Qo3tRDTxxg5uL9G6yOMNiWY3CMY7yKvV0sKSbxXKyzAxXNQ/QkpMOnLZKQHyI2ZWfdEcKZ/GUMC oU7hb9wQ==; Received: from i53875a11.versanet.de ([83.135.90.17] helo=phil..) by gloria.sntech.de with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1vJaYZ-0003BD-Pp; Thu, 13 Nov 2025 17:52:23 +0100 From: Heiko Stuebner To: lee@kernel.org Cc: linux-kernel@vger.kernel.org, heiko@sntech.de Subject: [PATCH v3 1/4] mfd: qnap-mcu: Calculate the checksum on the actual number of bytes received Date: Thu, 13 Nov 2025 17:52:15 +0100 Message-ID: <20251113165218.449616-2-heiko@sntech.de> X-Mailer: git-send-email 2.47.2 In-Reply-To: <20251113165218.449616-1-heiko@sntech.de> References: <20251113165218.449616-1-heiko@sntech.de> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" In the case of an error message, the number of received bytes can be less than originally expected but still contain a valid message. If the transfer itself ended in an error we would exit earlier already. So calculate the checksum on the number of received bytes and not the number of expected bytes. Signed-off-by: Heiko Stuebner --- drivers/mfd/qnap-mcu.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/mfd/qnap-mcu.c b/drivers/mfd/qnap-mcu.c index 2be429a50611..e3210541ec56 100644 --- a/drivers/mfd/qnap-mcu.c +++ b/drivers/mfd/qnap-mcu.c @@ -175,8 +175,8 @@ int qnap_mcu_exec(struct qnap_mcu *mcu, return -ETIMEDOUT; } =20 - crc =3D qnap_mcu_csum(rx, reply_data_size); - if (crc !=3D rx[reply_data_size]) { + crc =3D qnap_mcu_csum(rx, reply->received - QNAP_MCU_CHECKSUM_SIZE); + if (crc !=3D rx[reply->received - QNAP_MCU_CHECKSUM_SIZE]) { dev_err(&mcu->serdev->dev, "Invalid Checksum received\n"); return -EIO; } --=20 2.47.2 From nobody Wed Dec 17 14:24:44 2025 Received: from gloria.sntech.de (gloria.sntech.de [185.11.138.130]) (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 11A1435292C for ; Thu, 13 Nov 2025 16:52:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.11.138.130 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763052747; cv=none; b=BPzCABsaxaqYXyjFO+u0TkDo/hN7cw3TVmhG1f2JY6PqylrReXW/ONvVaqO5OpAVmcRZnWysdWBiUBzY4x9p9IosGeCL3Auk8WGIGEse+WcwCgAdo2Y9zc/TY/5B8/4aGLAZx5JDFRGhT8Nu4uGixuq5QumcMxoi1KOLbOjXHYM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763052747; c=relaxed/simple; bh=N+Ft/PmrtbS1c2vl4AHC6AfYZVStrjBDS5Fxlyfgs08=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ERAANwCrWf/bOjSTllVngy2vm/iehr6wDCwFxEtqkhECVXWmYzvyDLRtJPli3Lgl+pfV10CHBbQ/B2QrMtZsU+gsqjYH3yugGF+i/vme6LK2+OaL0Umj+oNOY0P7tYFDPiFPbFmM3FWYovuZFLJ9JSfSiMwbbWoHNBtz4MhxJuM= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=sntech.de; spf=pass smtp.mailfrom=sntech.de; dkim=pass (2048-bit key) header.d=sntech.de header.i=@sntech.de header.b=0EPAovV5; arc=none smtp.client-ip=185.11.138.130 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=sntech.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=sntech.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=sntech.de header.i=@sntech.de header.b="0EPAovV5" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sntech.de; s=gloria202408; h=Content-Transfer-Encoding:MIME-Version:References: In-Reply-To:Message-ID:Date:Subject:Cc:To:From:Reply-To:Content-Type; bh=nQYxBu/Q09Up2UjAV3Yg5ScyfmPTkQa5TKMKUGdESZo=; b=0EPAovV5uJ9I4Gl+FdrSz9CFI7 ITev1dVXBwEZ3DRtZbNNMtUWd739+xgBuR0I65e2Skwt3oDO7ATFvwwdF/F1YBPikF0EmLakX006w 9PIBqsajNCHbmA4zzRKWiFErRZNspjdJygT1hJtU4vW47lOCoCC9EIO30cCxjwyF+kWCvrTaMItuZ gPuGRhA2Qpo88ZYBJVEgOTHTaX4+MesRceuOlyeVWfRHR+DDX+hlZ07HVTO2hqGQWJgnlkvAUyDey 0pDtnu61JbPRg/doGVKZZG3PzyDT4YJ3gDcxoRRJDx2YIMG480sXHjNSmqfVDwrPZANxsy2Lnt1Ce CYQtIx2g==; Received: from i53875a11.versanet.de ([83.135.90.17] helo=phil..) by gloria.sntech.de with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1vJaYa-0003BD-0M; Thu, 13 Nov 2025 17:52:24 +0100 From: Heiko Stuebner To: lee@kernel.org Cc: linux-kernel@vger.kernel.org, heiko@sntech.de Subject: [PATCH v3 2/4] mfd: qnap-mcu: Use EPROTO in stead of EIO on checksum errors Date: Thu, 13 Nov 2025 17:52:16 +0100 Message-ID: <20251113165218.449616-3-heiko@sntech.de> X-Mailer: git-send-email 2.47.2 In-Reply-To: <20251113165218.449616-1-heiko@sntech.de> References: <20251113165218.449616-1-heiko@sntech.de> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" EPROTO stands for protocol error and a lot of driver already use it to designate errors in the sent or received data from a peripheral. So use it in the qnap-mcu as well for checksum errors. Signed-off-by: Heiko Stuebner --- drivers/mfd/qnap-mcu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/mfd/qnap-mcu.c b/drivers/mfd/qnap-mcu.c index e3210541ec56..b4b630f7d413 100644 --- a/drivers/mfd/qnap-mcu.c +++ b/drivers/mfd/qnap-mcu.c @@ -178,7 +178,7 @@ int qnap_mcu_exec(struct qnap_mcu *mcu, crc =3D qnap_mcu_csum(rx, reply->received - QNAP_MCU_CHECKSUM_SIZE); if (crc !=3D rx[reply->received - QNAP_MCU_CHECKSUM_SIZE]) { dev_err(&mcu->serdev->dev, "Invalid Checksum received\n"); - return -EIO; + return -EPROTO; } =20 memcpy(reply_data, rx, reply_data_size); --=20 2.47.2 From nobody Wed Dec 17 14:24:44 2025 Received: from gloria.sntech.de (gloria.sntech.de [185.11.138.130]) (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 4D49C3557E7 for ; Thu, 13 Nov 2025 16:52:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.11.138.130 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763052747; cv=none; b=QSsg7g8r9/3pwziMnD+IRf8icT89lTWKeVKrD1RLRBtct7quojK/49p6UbC1fW9lOFgB5IAFiQXGIyNJ2mMWLb7S91UkBYo2aLef5bLip0/uMppgwS4qYujB0h5pd/hdsR6I2S+3sXOSoNl6YF445S+81/z8OBgZubggFYV/4vo= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763052747; c=relaxed/simple; bh=DY/Ofcn/Ow8r+LCBGOumGnV6d/7pc2frhjwOPeU7DJ0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=kF3rCN+IWq3lhjcXvvvbsp11ObDCRoMK9x32IJ0UNoDIgmeyzL4dToXh4sU1aXjP6hsv6TXT8Wd45mHfZnvgstJWz5U9GvISbeB0HB7b1G+WC7Cd8i1s1nwFd49ANmCPcrEDwkQzoRbSA8kuh17WBKREq3+7dm2pjL2wWUO5pkw= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=sntech.de; spf=pass smtp.mailfrom=sntech.de; dkim=pass (2048-bit key) header.d=sntech.de header.i=@sntech.de header.b=CQOUZbWU; arc=none smtp.client-ip=185.11.138.130 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=sntech.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=sntech.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=sntech.de header.i=@sntech.de header.b="CQOUZbWU" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sntech.de; s=gloria202408; h=Content-Transfer-Encoding:MIME-Version:References: In-Reply-To:Message-ID:Date:Subject:Cc:To:From:Reply-To:Content-Type; bh=YXITm8DEAzGdardV/rwB/49K9rMVAUg6IGseVbSkN+U=; b=CQOUZbWU5pJXyk6xboN3VKCqPS 63gizcWI8JkiXIkZVcehdHJeVPbIbLrjhtmK2+m9XcxInawdn2x6/K9ejVrRAq2r7Szt2eu1/s2H3 JfHJDoOqRVGU1AiMYRQxgAk14sizAAmSdDPa45lxrqIahoYHU4LaF9CHW0zv6wTv3q9j0PziaHQsK UMaEEF+LmBUk+6ykJU4uBlqQzI45bYiNwuKzL/jZ22gDZbpudDHQXR4kj/226KpSK9BHa47vK0KDy dbKCqX2RU/sir9G1wq2bpE7dE9kv+0JMlA7Y6lyO/jyQyJNn8gNBwjv2Syxh0/MYl6WC0BtQiz/DE dGGPViNg==; Received: from i53875a11.versanet.de ([83.135.90.17] helo=phil..) by gloria.sntech.de with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1vJaYa-0003BD-7O; Thu, 13 Nov 2025 17:52:24 +0100 From: Heiko Stuebner To: lee@kernel.org Cc: linux-kernel@vger.kernel.org, heiko@sntech.de Subject: [PATCH v3 3/4] mfd: qnap-mcu: Move checksum verification to its own function Date: Thu, 13 Nov 2025 17:52:17 +0100 Message-ID: <20251113165218.449616-4-heiko@sntech.de> X-Mailer: git-send-email 2.47.2 In-Reply-To: <20251113165218.449616-1-heiko@sntech.de> References: <20251113165218.449616-1-heiko@sntech.de> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" We'll need the checksum check in a second place in the future, so move the verification code to a separate function. Signed-off-by: Heiko Stuebner --- drivers/mfd/qnap-mcu.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/drivers/mfd/qnap-mcu.c b/drivers/mfd/qnap-mcu.c index b4b630f7d413..cd836bdd44a8 100644 --- a/drivers/mfd/qnap-mcu.c +++ b/drivers/mfd/qnap-mcu.c @@ -78,6 +78,13 @@ static u8 qnap_mcu_csum(const u8 *buf, size_t size) return csum; } =20 +static bool qnap_mcu_verify_checksum(const u8 *buf, size_t size) +{ + u8 crc =3D qnap_mcu_csum(buf, size - QNAP_MCU_CHECKSUM_SIZE); + + return crc =3D=3D buf[size - QNAP_MCU_CHECKSUM_SIZE]; +} + static int qnap_mcu_write(struct qnap_mcu *mcu, const u8 *data, u8 data_si= ze) { unsigned char tx[QNAP_MCU_TX_BUFFER_SIZE]; @@ -150,7 +157,6 @@ int qnap_mcu_exec(struct qnap_mcu *mcu, size_t length =3D reply_data_size + QNAP_MCU_CHECKSUM_SIZE; struct qnap_mcu_reply *reply =3D &mcu->reply; int ret =3D 0; - u8 crc; =20 if (length > sizeof(rx)) { dev_err(&mcu->serdev->dev, "expected data too big for receive buffer"); @@ -175,8 +181,7 @@ int qnap_mcu_exec(struct qnap_mcu *mcu, return -ETIMEDOUT; } =20 - crc =3D qnap_mcu_csum(rx, reply->received - QNAP_MCU_CHECKSUM_SIZE); - if (crc !=3D rx[reply->received - QNAP_MCU_CHECKSUM_SIZE]) { + if (!qnap_mcu_verify_checksum(rx, reply->received)) { dev_err(&mcu->serdev->dev, "Invalid Checksum received\n"); return -EPROTO; } --=20 2.47.2 From nobody Wed Dec 17 14:24:44 2025 Received: from gloria.sntech.de (gloria.sntech.de [185.11.138.130]) (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 8C1283557E9 for ; Thu, 13 Nov 2025 16:52:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.11.138.130 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763052748; cv=none; b=kvMMBy6duQDZD7WNCc8n5/PNssTk+V+vSfvUzaY2tmeGn4OWdVgeCmuawVshJToyuoIfpvZ5AqEBcXNPUucheSpdjhbX9HQxhELr/vYwq3nbbZmroZwxEoh1hqKuxqCgU6L55ual2RMOBWAExlc5ust2zcrS9zzYw+n8NOeUUmQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763052748; c=relaxed/simple; bh=oPRjKZ1xsd7SVCmP6E0GR/wJcQUVRvkY+MJ+du6gUOM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=G6NXemhqc1T+HEvhjGjFkJmeO+59P5zTyhAu+nEjMCf3MRVFLqMJqVlRPfhzT1dSNs0b18N3xQ0vhIclErLgBZRs/HYa5rAZqUD6jF+Eic1RXcffH3KDV0PhunhC5NeHbW4QMRE8ADxwwIsWJFK9R8eZ+8Y6ppcMA2PcO8izB1w= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=sntech.de; spf=pass smtp.mailfrom=sntech.de; dkim=pass (2048-bit key) header.d=sntech.de header.i=@sntech.de header.b=lek6BLS5; arc=none smtp.client-ip=185.11.138.130 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=sntech.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=sntech.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=sntech.de header.i=@sntech.de header.b="lek6BLS5" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sntech.de; s=gloria202408; h=Content-Transfer-Encoding:MIME-Version:References: In-Reply-To:Message-ID:Date:Subject:Cc:To:From:Reply-To:Content-Type; bh=jYBrmYaHTSbXHLh4eFSlIiIZzcE0BQLWjTEQ8a2mK4o=; b=lek6BLS5M6XaQL7w+0dSH6JJ0n W8B2XtAdgycCzKouHMgZm1beyBUnkJm+Tc/RFsdTGY87B2XQci5E0/wmtWlG9FiOz+xHfIB/Ses03 wTwoWoGAPHc7/2HGKUc/WeH/uCb63BM/eJ9aJgqC5x4nQ4iZbHXW92EFJ5Ode03VJCzjnHCBaDGTZ wUYBQzwq8ZhpMJjoW2zIBbiAkqywA2j1A0IuqApZ1k7yGmFRTeNxphyiuiRjk5A94rcinn6dNDa8M dtBLFFI9i/TWOiH0Ix0UlpEzBr9a+w7hc5//yidQhjZaQJUfb0nGq05CmezsTKXQSu4zNIJZIhnyd /JU7xC4Q==; Received: from i53875a11.versanet.de ([83.135.90.17] helo=phil..) by gloria.sntech.de with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1vJaYa-0003BD-FU; Thu, 13 Nov 2025 17:52:24 +0100 From: Heiko Stuebner To: lee@kernel.org Cc: linux-kernel@vger.kernel.org, heiko@sntech.de Subject: [PATCH v3 4/4] mfd: qnap-mcu: Add proper error handling for command errors Date: Thu, 13 Nov 2025 17:52:18 +0100 Message-ID: <20251113165218.449616-5-heiko@sntech.de> X-Mailer: git-send-email 2.47.2 In-Reply-To: <20251113165218.449616-1-heiko@sntech.de> References: <20251113165218.449616-1-heiko@sntech.de> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Further investigation revealed that the MCU in QNAP devices may return two error states. One "@8" for a checksum error in the submitted command and one "@9" for any generic (and sadly unspecified) error. These error codes with 2 data character can of course also be shorter then the expected reply length for the submitted command, so we'll need to check the received data for error codes and exit the receive portion early in that case. Signed-off-by: Heiko Stuebner --- drivers/mfd/qnap-mcu.c | 66 +++++++++++++++++++++++++++++++++++++++++- 1 file changed, 65 insertions(+), 1 deletion(-) diff --git a/drivers/mfd/qnap-mcu.c b/drivers/mfd/qnap-mcu.c index cd836bdd44a8..f81c69f22254 100644 --- a/drivers/mfd/qnap-mcu.c +++ b/drivers/mfd/qnap-mcu.c @@ -19,6 +19,7 @@ /* The longest command found so far is 5 bytes long */ #define QNAP_MCU_MAX_CMD_SIZE 5 #define QNAP_MCU_MAX_DATA_SIZE 36 +#define QNAP_MCU_ERROR_SIZE 2 #define QNAP_MCU_CHECKSUM_SIZE 1 =20 #define QNAP_MCU_RX_BUFFER_SIZE \ @@ -103,6 +104,48 @@ static int qnap_mcu_write(struct qnap_mcu *mcu, const = u8 *data, u8 data_size) return serdev_device_write(mcu->serdev, tx, length, HZ); } =20 +static bool qnap_mcu_is_error_msg(size_t size) +{ + return (size =3D=3D QNAP_MCU_ERROR_SIZE + QNAP_MCU_CHECKSUM_SIZE); +} + +static bool qnap_mcu_reply_is_generic_error(unsigned char *buf, size_t siz= e) +{ + if (!qnap_mcu_is_error_msg(size)) + return false; + + if (buf[0] =3D=3D '@' && buf[1] =3D=3D '9') + return true; + + return false; +} + +static bool qnap_mcu_reply_is_checksum_error(unsigned char *buf, size_t si= ze) +{ + if (!qnap_mcu_is_error_msg(size)) + return false; + + if (buf[0] =3D=3D '@' && buf[1] =3D=3D '8') + return true; + + return false; +} + +static bool qnap_mcu_reply_is_any_error(struct qnap_mcu *mcu, unsigned cha= r *buf, size_t size) +{ + if (qnap_mcu_reply_is_generic_error(buf, size)) { + dev_err(&mcu->serdev->dev, "Controller sent generic error response\n"); + return true; + } + + if (qnap_mcu_reply_is_checksum_error(buf, size)) { + dev_err(&mcu->serdev->dev, "Controller received invalid checksum for the= command\n"); + return true; + } + + return false; +} + static size_t qnap_mcu_receive_buf(struct serdev_device *serdev, const u8 = *buf, size_t size) { struct device *dev =3D &serdev->dev; @@ -136,6 +179,24 @@ static size_t qnap_mcu_receive_buf(struct serdev_devic= e *serdev, const u8 *buf, } } =20 + /* + * We received everything the uart had to offer for now. + * This could mean that either the uart will send more in a 2nd + * receive run, or that the MCU cut the reply short because it + * sent an error code instead of the expected reply. + * + * So check if the received data has the correct size for an error + * reply and if it matches, is an actual error code. + */ + if (qnap_mcu_is_error_msg(reply->received) && + qnap_mcu_verify_checksum(reply->data, reply->received) && + qnap_mcu_reply_is_any_error(mcu, reply->data, reply->received)) { + /* The reply was an error code, we're done */ + reply->length =3D 0; + + complete(&reply->done); + } + /* * The only way to get out of the above loop and end up here * is through consuming all of the supplied data, so here we @@ -182,10 +243,13 @@ int qnap_mcu_exec(struct qnap_mcu *mcu, } =20 if (!qnap_mcu_verify_checksum(rx, reply->received)) { - dev_err(&mcu->serdev->dev, "Invalid Checksum received\n"); + dev_err(&mcu->serdev->dev, "Invalid Checksum received from controller\n"= ); return -EPROTO; } =20 + if (qnap_mcu_reply_is_any_error(mcu, rx, reply->received)) + return -EPROTO; + memcpy(reply_data, rx, reply_data_size); =20 return 0; --=20 2.47.2