[PATCH] libata: fix checking of DMA state

From: "Reimar Döffinger" <Reimar.Doeffinger@gmx.de>
To: Damien Le Moal <Damien.LeMoal@wdc.com>,
	linux-ide@vger.kernel.org, Jens Axboe <axboe@kernel.dk>,
	hch@infradead.org
Subject: [PATCH] libata: fix checking of DMA state
Date: Thu, 19 Aug 2021 10:13:40 +0200	[thread overview]
Message-ID: <20210819081340.4362-1-Reimar.Doeffinger@gmx.de> (raw)
In-Reply-To: <DM6PR04MB7081AB7034F116CDFBA43890E7FF9@DM6PR04MB7081.namprd04.prod.outlook.com>

Checking if DMA is enabled should be done via the
ata_dma_enabled helper function, since the init state
0xff indicates disabled.
Only the libata-core logic is tested on actual devices,
the other changes are based on code review only.
---
Changes to previous version:
- removed initialization change for SATA. I got confused by the
  ping-pong between libata-eh and libata-core and thought SATA did not
  set up xfermode
- reviewed other cases that used dma_mode in boolean context and those
  seemed to need changing as well, so added them to patch.
  I did not see any places that would set dma_mode to 0 ever, so I
  do think they were all indeed wrong.

 drivers/ata/libata-core.c  | 2 +-
 drivers/ata/libata-scsi.c  | 4 ++--
 drivers/ata/pata_ali.c     | 2 +-
 drivers/ata/pata_optidma.c | 4 ++--
 drivers/ata/pata_radisys.c | 2 +-
 5 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 9934f6c465f4..52469b39d424 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -2004,7 +2004,7 @@ unsigned int ata_read_log_page(struct ata_device *dev, u8 log,
 
 retry:
 	ata_tf_init(dev, &tf);
-	if (dev->dma_mode && ata_id_has_read_log_dma_ext(dev->id) &&
+	if (ata_dma_enabled(dev) && ata_id_has_read_log_dma_ext(dev->id) &&
 	    !(dev->horkage & ATA_HORKAGE_NO_DMA_LOG)) {
 		tf.command = ATA_CMD_READ_LOG_DMA_EXT;
 		tf.protocol = ATA_PROT_DMA;
diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index b9588c52815d..9e51251161e9 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -3023,7 +3023,7 @@ static unsigned int ata_scsi_pass_thru(struct ata_queued_cmd *qc)
 	ata_qc_set_pc_nbytes(qc);
 
 	/* We may not issue DMA commands if no DMA mode is set */
-	if (tf->protocol == ATA_PROT_DMA && dev->dma_mode == 0) {
+	if (tf->protocol == ATA_PROT_DMA && !ata_dma_enabled(dev)) {
 		fp = 1;
 		goto invalid_fld;
 	}
@@ -3173,7 +3173,7 @@ static unsigned int ata_scsi_write_same_xlat(struct ata_queued_cmd *qc)
 	u8 unmap = cdb[1] & 0x8;
 
 	/* we may not issue DMA commands if no DMA mode is set */
-	if (unlikely(!dev->dma_mode))
+	if (unlikely(!ata_dma_enabled(dev)))
 		goto invalid_opcode;
 
 	/*
diff --git a/drivers/ata/pata_ali.c b/drivers/ata/pata_ali.c
index 557ecf466102..28b56811306f 100644
--- a/drivers/ata/pata_ali.c
+++ b/drivers/ata/pata_ali.c
@@ -215,7 +215,7 @@ static void ali_set_piomode(struct ata_port *ap, struct ata_device *adev)
 		struct ata_timing p;
 		ata_timing_compute(pair, pair->pio_mode, &p, T, 1);
 		ata_timing_merge(&p, &t, &t, ATA_TIMING_SETUP|ATA_TIMING_8BIT);
-		if (pair->dma_mode) {
+		if (ata_dma_enabled(pair)) {
 			ata_timing_compute(pair, pair->dma_mode, &p, T, 1);
 			ata_timing_merge(&p, &t, &t, ATA_TIMING_SETUP|ATA_TIMING_8BIT);
 		}
diff --git a/drivers/ata/pata_optidma.c b/drivers/ata/pata_optidma.c
index f6278d9de348..ad1090b90e52 100644
--- a/drivers/ata/pata_optidma.c
+++ b/drivers/ata/pata_optidma.c
@@ -153,7 +153,7 @@ static void optidma_mode_setup(struct ata_port *ap, struct ata_device *adev, u8
 	if (pair) {
 		u8 pair_addr;
 		/* Hardware constraint */
-		if (pair->dma_mode)
+		if (ata_dma_enabled(pair))
 			pair_addr = 0;
 		else
 			pair_addr = addr_timing[pci_clock][pair->pio_mode - XFER_PIO_0];
@@ -301,7 +301,7 @@ static u8 optidma_make_bits43(struct ata_device *adev)
 	};
 	if (!ata_dev_enabled(adev))
 		return 0;
-	if (adev->dma_mode)
+	if (ata_dma_enabled(adev))
 		return adev->dma_mode - XFER_MW_DMA_0;
 	return bits43[adev->pio_mode - XFER_PIO_0];
 }
diff --git a/drivers/ata/pata_radisys.c b/drivers/ata/pata_radisys.c
index 8fde4a86401b..626b14f0f2ea 100644
--- a/drivers/ata/pata_radisys.c
+++ b/drivers/ata/pata_radisys.c
@@ -173,7 +173,7 @@ static unsigned int radisys_qc_issue(struct ata_queued_cmd *qc)
 	if (adev != ap->private_data) {
 		/* UDMA timing is not shared */
 		if (adev->dma_mode < XFER_UDMA_0) {
-			if (adev->dma_mode)
+			if (ata_dma_enabled(adev))
 				radisys_set_dmamode(ap, adev);
 			else if (adev->pio_mode)
 				radisys_set_piomode(ap, adev);
-- 
2.32.0

