From mboxrd@z Thu Jan 1 00:00:00 1970 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 54EA9290BBF; Thu, 3 Apr 2025 19:09:06 +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=1743707347; cv=none; b=pl74p8kE4co1LtQ36sWJoOKY8lzWViB2iXtAiJj8D9mWdiEBOq3GYgVolqk2eilKtxR1DTaBkdGIc4PX8kX/XZjEGcPaxSSf7I2yh9kss3NbsFZzsHHQ9bWvPkv/M7u34Kc151QOHF3LFXElPZIF6bgCC+1PsLqcW5utQGKNrjs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743707347; c=relaxed/simple; bh=vzZz1AkG22CglZ5ijuwVEv2MycnZbPnoy7xDovhMsWc=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=gW2R7RHrF29uw3kidv6SKC8WSwXUhPxGHLimQYuE4LEE10xGAQ+VvJG/sdzpEve2kYxBL1M2nd3s+McC2dqS1VEN+ZJDq6FccmYalKUMfg0puHmKUJgMFpnAU3VRSI4LfvVCUQoEBz4RrnCsAGOedkF5hSs155pGK8KCNv4oyNQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=JdmKh2tI; 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="JdmKh2tI" Received: by smtp.kernel.org (Postfix) with ESMTPSA id F37D4C4CEE9; Thu, 3 Apr 2025 19:09:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1743707346; bh=vzZz1AkG22CglZ5ijuwVEv2MycnZbPnoy7xDovhMsWc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=JdmKh2tILV56Xsauqu9FK4ExUzT10jysrZE0m2OAT9NX0CZ9x9KHf3PBVO9odQ8Dh In8HVDm45rYGQbKk0GN0jymV/OUT0VZpv+LeceSp7LCUT5tG/ah4uB389Huz8j3vDx VAYjyFx6JeKWaoTho6ZlO0QHmZXN8d9SKm/6Eaw/4lL7e7hN6XLljjAR6U5KAnaG2i HEpk/q8JQqL2UMssBLKh4UnmjahsCOxlXHxLVIE2UH5euTI2VkhhF9F336vp/WbTaq MWqxuiz7uaGutIeqqvMRV1GrLs2aaTLwPumSQqi7T9HzR4bpeh0Oy146NPMnwRXEYu vvee66aVbkDYQ== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Niklas Cassel , Philip Pemberton , Damien Le Moal , Sasha Levin , linux-ide@vger.kernel.org Subject: [PATCH AUTOSEL 6.1 08/18] ata: libata-eh: Do not use ATAPI DMA for a device limited to PIO mode Date: Thu, 3 Apr 2025 15:08:34 -0400 Message-Id: <20250403190845.2678025-8-sashal@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250403190845.2678025-1-sashal@kernel.org> References: <20250403190845.2678025-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: linux-ide@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.1.132 Content-Transfer-Encoding: 8bit From: Niklas Cassel [ Upstream commit 91ec84f8eaddbc93d7c62e363d68aeb7b89879c7 ] atapi_eh_request_sense() currently uses ATAPI DMA if the SATA controller has ATA_FLAG_PIO_DMA (PIO cmds via DMA) set. However, ATA_FLAG_PIO_DMA is a flag that can be set by a low-level driver on a port at initialization time, before any devices are scanned. If a controller detects a connected device that only supports PIO, we set the flag ATA_DFLAG_PIO. Modify atapi_eh_request_sense() to not use ATAPI DMA if the connected device only supports PIO. Reported-by: Philip Pemberton Closes: https://lore.kernel.org/linux-ide/c6722ee8-5e21-4169-af59-cbbae9edc02f@philpem.me.uk/ Tested-by: Philip Pemberton Reviewed-by: Damien Le Moal Link: https://lore.kernel.org/r/20250221015422.20687-2-cassel@kernel.org Signed-off-by: Niklas Cassel Signed-off-by: Sasha Levin --- drivers/ata/libata-eh.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c index 3f327ba759fd9..586982a2a61ff 100644 --- a/drivers/ata/libata-eh.c +++ b/drivers/ata/libata-eh.c @@ -1510,8 +1510,15 @@ unsigned int atapi_eh_request_sense(struct ata_device *dev, tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE; tf.command = ATA_CMD_PACKET; - /* is it pointless to prefer PIO for "safety reasons"? */ - if (ap->flags & ATA_FLAG_PIO_DMA) { + /* + * Do not use DMA if the connected device only supports PIO, even if the + * port prefers PIO commands via DMA. + * + * Ideally, we should call atapi_check_dma() to check if it is safe for + * the LLD to use DMA for REQUEST_SENSE, but we don't have a qc. + * Since we can't check the command, perhaps we should only use pio? + */ + if ((ap->flags & ATA_FLAG_PIO_DMA) && !(dev->flags & ATA_DFLAG_PIO)) { tf.protocol = ATAPI_PROT_DMA; tf.feature |= ATAPI_PKT_DMA; } else { -- 2.39.5