From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794717582; b=40eY+HlWAw3l5ZQOCd9ee/gve8jMw8+8sQcE7uSKM2OHtFEPBCNW4u23Nabrzz6cJ/Fj zr1uu7v6BuGxYSLxjQqEZVdVP+2rjBtu+0urFtmmflt/OCURCRewOzVLLCJ7tW+lcKAp7 4/2gqUYARYNxZKuu2qtRcBLyZ+VEoOhPn/SPMUuK6TM/awFW98aobkMC+p5MZaS64uf4a eufBemUmiKKynaA+vMr6dYPNPxVHMmFsFEiyAKyeQNMXnd/igkhuFMyt0sSa9pSwOAa0Q fx8L0N/CrGTkH3iA3CVD4RRNFa97aAWv77M+94IKT1kiBGyVUQfEeLAb3y4hSoZSj7g== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794717582; h=Received:DKIM-Signature:From:Date:Subject:MIME-Version:Content-Type: Content-Transfer-Encoding:Message-Id:X-B4-Tracking:X-Change-ID:To:Cc: X-Mailer:X-Developer-Signature:X-Developer-Key; bh=Zv9QKzRQEPxxzpa2oYAmnKto1hcqlcY9m59gDaJs/hc=; b=JN1fv7aUPOKSyIbkeZcBzYpXY0m7nL4bLaUARDsVju5jbPy45CsZojEwMV97IoHPZDyi Gmp2890aPO3tlvgINVK+b/LKX4Kah3Yv6zHpXUhuKAMW3fYWytf4iFXrCVWzv9MZcgqQs 8pZHHzQYyEmiDh5oHED81iGF1AidPlIc1qRsleKiobXYXYZMwE21C0CU+D0WldERD3emE rU9lu3xuHGlB/mJvMYBwxmDByxleJyMZuxyGYIcqyVZSy06FsQQpJG5lcYfBHp/h21mp0 QGX2viBTv1rEfICsGi8St0x4mOSg2Hw2t/uUtL7TJCruq4ZRdW08DE1ho+yQieIBh3A== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=AWWzAGpy; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id EC022606A329; Sun, 15 Nov 2026 04:39:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=AWWzAGpy Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6A0721F000C4; Sun, 15 Nov 2026 04:39:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794717581; bh=Zv9QKzRQEPxxzpa2oYAmnKto1hcqlcY9m59gDaJs/hc=; h=From:Date:Subject:To:Cc; b=AWWzAGpy8xGbmyCue4Ch4R1fdVbBzavG+cKebKkUsf3/VvavKJj3qZAFiN9NPMQDR R04vFsbioN0i2S8CN/szo3mM/7SEzVLSE9d6Ie9pQGLPL/NTjWHEMrNXKFjI5A+ULC kD7dJTcl+Ikvbk7RtIDbCvLD1waTSfQGedzhNn4nDJ/bjQ96xmRfWG7Qr1hqbGlibZ Wwct8Lw4qeUYs7bYFaZ4xqrs9CrOlzHP9A58wyoVwFink4esBXYLm/eJZ/Alz12HoG U6anprDOirRZv7b+Y2fQ19duimyuEuq8k0ZwGKbd/ERDvcuKiyWB1jC92ISeizPqw+ hj899qq2v/Ycg== From: Nathan Chancellor Date: Sat, 14 Nov 2026 21:39:29 -0700 Subject: [PATCH net] qca_spi: Avoid unsequenced accesses to jiffies in qcaspi_netdev_tx_timeout() X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20261114-qca_spi-wunsequenced-v1-1-6b219b906db7@kernel.org> X-B4-Tracking: v=1; b=H4sIAAAAAAAA/yWMwQrCMBAFf6Xs2YBb0lD8FRGJ6VPXw9pmGxVK/ 71RjzMws5AhC4wOzUIZLzF5agXeNZTuUW9wMlSmdt8GZvZuSvFso7h3UcNUoAmDiz2j84FD7z3 VdMy4yue3PZJiptNfWrk8kObvkNZ1AzpIlyl9AAAA X-Change-ID: 20261114-qca_spi-wunsequenced-a81e54616844 To: Stefan Wahren , Andrew Lunn , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, llvm@lists.linux.dev, stable@vger.kernel.org, Nathan Chancellor X-Mailer: b4 0.17-dev X-Developer-Signature: v=1; a=openpgp-sha256; l=2213; i=nathan@kernel.org; h=from:subject:message-id; bh=8diMkiPDp0+wFaZenuORVyRA9hNw0BoDQxVNwlId7QM=; b=owGbwMvMwCUmm602sfCA1DTG02pJDFk/zVvvbP7OZ3D5c21H2jTxaZUfdVrYazyVX/6aYbjp3 5G5HIucO0pZGMS4GGTFFFmqH6seNzScc5bxxqlJMHNYmUCGMHBxCsBEbLUY/gpsqrltavTFyj2l V+Hri/Bp0utdxFqmbXXbO5FtkVWKbALDX5k91bN+fNrnWD9DwGxa/NK7Zhd8z4a+Covr4b6mqNP KyAoA X-Developer-Key: i=nathan@kernel.org; a=openpgp; fpr=2437CB76E544CB6AB3D9DFD399739260CB6CB716 After a recent improvement in clang to warn on unsequenced accesses to volatile variables [1], an instance appears in qcaspi_netdev_tx_timeout(), which can break the build with CONFIG_WERROR=y / W=e: drivers/net/ethernet/qualcomm/qca_spi.c:805:16: error: unsequenced accesses to volatile qualified 'jiffies' [-Werror,-Wunsequenced] 805 | jiffies, jiffies - dev_trans_start(dev)); | ~~~~~~~ ^ Per C11 5.1.2.3.2, accessing a volatile object is a side effect. Per C11 6.5.2, unsequenced side effects on the same scalar object are undefined behavior. Per C11 6.5.2.2.10/12, the evaluation of arguments in a function call is indeterminately sequenced, meaning any side effects in the arguments are unsequenced. Add a local variable to hold the value of jiffies before the function call so that there are no unsequenced side effects, clearing up the warning. Cc: stable@vger.kernel.org Fixes: 291ab06ecf67 ("net: qualcomm: new Ethernet over SPI driver for QCA7000") Closes: https://github.com/ClangBuiltLinux/linux/issues/2197 Link: https://github.com/llvm/llvm-project/commit/955715460eaf9188c241c74750637fc82dfcc423 [1] Signed-off-by: Nathan Chancellor --- drivers/net/ethernet/qualcomm/qca_spi.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/net/ethernet/qualcomm/qca_spi.c b/drivers/net/ethernet/qualcomm/qca_spi.c index 38a779f4b866..3ea745d4aef7 100644 --- a/drivers/net/ethernet/qualcomm/qca_spi.c +++ b/drivers/net/ethernet/qualcomm/qca_spi.c @@ -800,9 +800,10 @@ static void qcaspi_netdev_tx_timeout(struct net_device *dev, unsigned int txqueue) { struct qcaspi *qca = netdev_priv(dev); + unsigned long j = jiffies; netdev_info(qca->net_dev, "Transmit timeout at %ld, latency %ld\n", - jiffies, jiffies - dev_trans_start(dev)); + j, j - dev_trans_start(dev)); qca->net_dev->stats.tx_errors++; /* Trigger tx queue flush and QCA7000 reset */ set_bit(SPI_RESET, &qca->flags); --- base-commit: aa40afa831ebfe45e40a23721711059f2ac584d4 change-id: 20261114-qca_spi-wunsequenced-a81e54616844 Best regards, -- Cheers, Nathan