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 DA4952561D6; Thu, 3 Apr 2025 19:05:02 +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=1743707103; cv=none; b=rdCa+Fpqh1VR5WzYHgatS+bLlEI6c35N/wm/QGb/VYXUDdVAlvWwd6JZcwpPPRKUFD4fZ2R34HRv5CyL7AagXsyl3wuuIKXvEAYvQXrp+aIBK3c/s/YwZIhh63giAteFCC53U+XXwht44SKjDjnW0BSp+LTf0Nrcc5FXMVzjzvY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743707103; c=relaxed/simple; bh=ZCC9jh7ZVX2fGD7QT2FFdDBEpGSuODp4SIPv7b74Fa0=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=eva7hZmbUfqqguq0hFLF8+Skp6Vhfc06Am7gz0KUp5Dv11JPXsac5OW5YTWQxiSYAl1G+KvDWH4RiM1BTdydj66d/iRTA8GoJNNv7SO3hTQO4444v6L45fTXeuuTnf0Jilcxrv5GgHR0HAZfm+qnZebY0V39KBsmQKwojE3Niio= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=LFuzHmfI; 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="LFuzHmfI" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 891CAC4CEE9; Thu, 3 Apr 2025 19:05:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1743707102; bh=ZCC9jh7ZVX2fGD7QT2FFdDBEpGSuODp4SIPv7b74Fa0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=LFuzHmfIredzAfk1u1CXrg9OviDeP4enRyARAbpml8bnkbCKDBnGejx7MkgSmm9CE nSALjTRqyxyeaahy8nP5EeCF1GPx3MafkG2tZvi6vxeMlDwAR+ETYuGccZqdFD+k9u gNY0BSbioxd3pOahF5tJX1MrRNqnEBQiiYtJXn00DNOghPR/7XTQbioUBWVemQ8rMe VNhxBYJINpZIFDkmoBYgbVij5XpQBudTdgJaSAjLf+R7CioUZYmUis7/tA3/21r6Fx /BxhN6le7v65TMLOeTZm4t7DZ8SminnGZm0EWwbOAKS85hc0tFiB2dtwqAV0dlQycG eD8f12AB1opWw== 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 6.13 23/49] ata: libata-eh: Do not use ATAPI DMA for a device limited to PIO mode Date: Thu, 3 Apr 2025 15:03:42 -0400 Message-Id: <20250403190408.2676344-23-sashal@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250403190408.2676344-1-sashal@kernel.org> References: <20250403190408.2676344-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.13.9 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 3b303d4ae37a0..16cd676eae1f9 100644 --- a/drivers/ata/libata-eh.c +++ b/drivers/ata/libata-eh.c @@ -1542,8 +1542,15 @@ 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