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 746D3332EC5; Wed, 23 Sep 2026 14:47:34 +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=1790174855; cv=none; b=cdTAFDGxjFPbtvtRu+tZ9jidGz5RrbJkv0jDfLUfUnqQak7IF9WIzr9jksdlx6gBo1tcyHu55V+tGvIHgVYq/kHz30aHEScKfmH2KMZMqA2/Cl8BwPqBO/aN1xWYrEA1eklruJf46Nr0pxtx0Pp+2UazTVSemoAUTHZTSFkqguk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790174855; c=relaxed/simple; bh=29mDNEpr7rYV2ry46lvuNsY1ciu8iBaiseeJ/zj8Uj8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=RI0XOTTTh/9vd5SsqjrosajmgHSGRwXL0T3wCLZb6qm+syeaDRKmEt6Ty22HJu1KsRQh2YOwQoMm1UVr7CBDNLcvx+9Sp8nzINDjdOIah/LNF27cAV8lEweMW85fNUuLyGEw/16yNogE93S3Ehn1rRzRK7AG1QAWCW15hBuHPHE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=lcf86knn; 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="lcf86knn" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C70DB1F000FF; Wed, 23 Sep 2026 14:47:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1790174854; bh=/9oysZeDWvUP/3vQcVX3Da6BX4/cY4k8Urjcw2KCDMw=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=lcf86knn2A4uzqGmNEA1jvU9V+gMHoR7MmSSfH7Z2hLDfYsR68hH5KJegbeosEy2T LJTCy/QWL8WoAfxc3A1UOQhSf81AX4fe+Luu7IZLUW5sIGb2iggzr70D4VNZ7blMCG cetgix5Hi208fj1RlqHP2W+wluDNc9LLay7x94ps= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Roland Waltersson , Damien Le Moal , Niklas Cassel Subject: [PATCH 6.18 202/398] ata: libahci: clear PxCLBU and PxFBU for AHCI_HFLAG_32BIT_ONLY Date: Wed, 23 Sep 2026 16:04:36 +0200 Message-ID: <20260923140648.658737086@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260923140643.441954610@linuxfoundation.org> References: <20260923140643.441954610@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 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Niklas Cassel commit 82e47533221d4746947b74d2e79a478c36c6433a upstream. A user reported that commit 105c42566a55 ("ata: ahci: force 32-bit DMA for JMicron JMB582/JMB585") made the JMicron JMB585 unusable on his board. The failure is seen as soon as the ahci driver is probed, and booting with iommu=off does not solve the problem. Looking at the AHCI specification, PxCLBU and PxFBU are both read only '0' for HBAs that do not support 64-bit addressing. For HBAs that do support 64-bit addressing, the registers are read write, with a reset value that is Implementation Specific. When using the AHCI_HFLAG_32BIT_ONLY flag, the HBA does support 64-bit addressing, and a 32-bit DMA mask is set by simply clearing HOST_CAP_64. Thus, in this case, we need to explicitly clear the registers to 0. Fixes: 105c42566a55 ("ata: ahci: force 32-bit DMA for JMicron JMB582/JMB585") Fixes: c7a42156d99b ("ahci: disable 64bit dma on sb600") Cc: stable@vger.kernel.org Reported-by: Roland Waltersson Closes: https://lore.kernel.org/linux-ide/IA0PR17MB668730A4ECCD65F7A1DC3EDC9EB62@IA0PR17MB6687.namprd17.prod.outlook.com/ Reviewed-by: Damien Le Moal Link: https://lore.kernel.org/r/20260904134310.1465051-2-cassel@kernel.org Signed-off-by: Niklas Cassel Signed-off-by: Greg Kroah-Hartman --- drivers/ata/libahci.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) --- a/drivers/ata/libahci.c +++ b/drivers/ata/libahci.c @@ -748,15 +748,28 @@ void ahci_start_fis_rx(struct ata_port * struct ahci_port_priv *pp = ap->private_data; u32 tmp; - /* set FIS registers */ + /* + * On HBAs that only support 32-bit addressing PxCLBU is read only '0'. + * When applying the AHCI_HFLAG_32BIT_ONLY quirk, PxCLBU is RW, and the + * reset value is Implementation Specific, so we need to clear it to 0. + */ if (hpriv->cap & HOST_CAP_64) writel((pp->cmd_slot_dma >> 16) >> 16, port_mmio + PORT_LST_ADDR_HI); + else if (hpriv->flags & AHCI_HFLAG_32BIT_ONLY) + writel(0, port_mmio + PORT_LST_ADDR_HI); writel(pp->cmd_slot_dma & 0xffffffff, port_mmio + PORT_LST_ADDR); + /* + * On HBAs that only support 32-bit addressing PxFBU is read only '0'. + * When applying the AHCI_HFLAG_32BIT_ONLY quirk, PxFBU is RW, and the + * reset value is Implementation Specific, so we need to clear it to 0. + */ if (hpriv->cap & HOST_CAP_64) writel((pp->rx_fis_dma >> 16) >> 16, port_mmio + PORT_FIS_ADDR_HI); + else if (hpriv->flags & AHCI_HFLAG_32BIT_ONLY) + writel(0, port_mmio + PORT_FIS_ADDR_HI); writel(pp->rx_fis_dma & 0xffffffff, port_mmio + PORT_FIS_ADDR); /* enable FIS reception */