From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 32B70341AC7; Sat, 30 May 2026 17:55:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780163709; cv=none; b=RAbYjKIPLY9zBxmjPyc2Uha4AMmdWSSfc8ux7DuYkv+5ZdkkIVAb4I7DFFB/W93uSCy/kSJWyiN9hyDles7Xh6z5vcKqjR3vTcSJfQAi3C5vb604rRqrWLy+QqtUU34IgCKSh0riQKII6HhK68bq9ue738TIxtNpbGmI3ym6aPI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780163709; c=relaxed/simple; bh=drW4+MLtI7IamaDzFKQQ7Z+GWsSdzhWt28t7ii2M/EQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=au4RdT+pr+0dUpa4bAbZqOv4HYUfvvmvIXXFb0dzH0R24wOf7uO75Xu9JIQgfJCRR8kwZlIF10VINQ04svSqyVRvTWimZkPV/vntKeMdl0KNksFxC03LuGBsO5RsjNaBhVeF+Tj9x5d+3idTexm4iUcHr2Ey6fLTbYY7zPKFnbM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=AGi5+ne9; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="AGi5+ne9" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7698B1F00893; Sat, 30 May 2026 17:55:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1780163708; bh=FHgWuEPI4bqSmSORRBOFYGxCQ3jy1OfBHJKJ+Dv6gFM=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=AGi5+ne9IgKhwDIrGLm+uWIAfykFmLkrGtemgnatDXNNmUaFKyJi8kuPg0NE7O0tD Ndg64Yx567sHCLE1Ad92GV1sOprLSvzTxMfF1NghzMaLp5+V3q6+0xR3j5ht/LRuAe pinNYbB91YG0MNpuhqiBDlYdc1jLUAUVh0GVAOTc= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Lukas Wunner , Shuai Xue , Bjorn Helgaas , Kuppuswamy Sathyanarayanan Subject: [PATCH 5.15 339/776] PCI/AER: Clear only error bits in PCIe Device Status Date: Sat, 30 May 2026 18:00:53 +0200 Message-ID: <20260530160249.334119394@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260530160240.228940103@linuxfoundation.org> References: <20260530160240.228940103@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Shuai Xue commit a8aeea1bf3c80cc87983689e0118770e019bd4f3 upstream. Currently, pcie_clear_device_status() clears the entire PCIe Device Status register (PCI_EXP_DEVSTA) by writing back the value read from the register, which affects not only the error status bits but also other writable bits. According to PCIe r7.0, sec 7.5.3.5, this register contains: - RW1C error status bits (CED, NFED, FED, URD at bits 0-3): These are the four error status bits that need to be cleared. - Read-only bits (AUXPD at bit 4, TRPND at bit 5): Writing to these has no effect. - Emergency Power Reduction Detected (bit 6): A RW1C non-error bit introduced in PCIe r5.0 (2019). This is currently the only writable non-error bit in the Device Status register. Unconditionally clearing this bit can interfere with other software components that rely on this power management indication. - Reserved bits (RsvdZ): These bits are required to be written as zero. Writing 1s to them (as the current implementation may do) violates the specification. To prevent unintended side effects, modify pcie_clear_device_status() to only write 1s to the four error status bits (CED, NFED, FED, URD), leaving the Emergency Power Reduction Detected bit and reserved bits unaffected. Fixes: ec752f5d54d7 ("PCI/AER: Clear device status bits during ERR_FATAL and ERR_NONFATAL") Suggested-by: Lukas Wunner Signed-off-by: Shuai Xue Signed-off-by: Bjorn Helgaas Reviewed-by: Kuppuswamy Sathyanarayanan Reviewed-by: Lukas Wunner Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260211124624.49656-1-xueshuai@linux.alibaba.com Signed-off-by: Greg Kroah-Hartman --- drivers/pci/pci.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -2220,10 +2220,9 @@ EXPORT_SYMBOL_GPL(pci_set_pcie_reset_sta void pcie_clear_device_status(struct pci_dev *dev) { - u16 sta; - - pcie_capability_read_word(dev, PCI_EXP_DEVSTA, &sta); - pcie_capability_write_word(dev, PCI_EXP_DEVSTA, sta); + pcie_capability_write_word(dev, PCI_EXP_DEVSTA, + PCI_EXP_DEVSTA_CED | PCI_EXP_DEVSTA_NFED | + PCI_EXP_DEVSTA_FED | PCI_EXP_DEVSTA_URD); } /**