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pata_it821x: (partially) fix DMA in RAID mode

PATCH Applied Bartlomiej Zolnierkiewicz 2 participants 2 messages Jun 11, 2007 – Jun 20, 2007 libata

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Bartlomiej Zolnierkiewicz

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#0 lore raw

PATCH 1/1 pata_it821x: (partially) fix DMA in RAID mode

Code intended to check DMA status was checking DMA command register.

Moreover firmware seems to "forget" to set DMA capable bit for the slave device (at least in RAID mode but without ITE RAID volumes) so check device ID for DMA capable bit when deciding whether to use DMA and remove DMA status check completely.

Thanks to Pavol Simo for the bugreport and testing the initial fix.

This change unfortunately still doesn't fix DMA in RAID mode (which works fine with IDE it821x) but Alan is working on the missing pieces (pata_it821x vs libata EH issues).

Signed-off-by Bartlomiej Zolnierkiewicz <[email protected]>
Acked-by Alan Cox <[email protected]>
Cc Tejun Heo <[email protected]>

---
removed non-ASCII char from the patch description + added Alan's ACK

 drivers/ata/pata_it821x.c |   11 +++--------
 1 file changed, 3 insertions(+), 8 deletions(-)
drivers/ata/pata_it821x.c +3 -8
Index: b/drivers/ata/pata_it821x.c
===================================================================
@@ -2,6 +2,7 @@
  * pata_it821x.c 	- IT821x PATA for new ATA layer
  *			  (C) 2005 Red Hat Inc
  *			  Alan Cox <[email protected]>
+ *			  (C) 2007 Bartlomiej Zolnierkiewicz
  *
  * based upon
  *

@@ -79,7 +80,7 @@
 
 
 #define DRV_NAME "pata_it821x"
-#define DRV_VERSION "0.3.6"
+#define DRV_VERSION "0.3.7"
 
 struct it821x_dev
 {

@@ -460,14 +461,8 @@ static unsigned int it821x_passthru_qc_i
 
 static int it821x_smart_set_mode(struct ata_port *ap, struct ata_device **unused)
 {
-	int dma_enabled = 0;
 	int i;
 
-	/* Bits 5 and 6 indicate if DMA is active on master/slave */
-	/* It is possible that BMDMA isn't allocated */
-	if (ap->ioaddr.bmdma_addr)
-		dma_enabled = ioread8(ap->ioaddr.bmdma_addr + ATA_DMA_CMD);
-
 	for (i = 0; i < ATA_MAX_DEVICES; i++) {
 		struct ata_device *dev = &ap->device[i];
 		if (ata_dev_enabled(dev)) {

@@ -476,7 +471,7 @@ static int it821x_smart_set_mode(struct 
 			dev->dma_mode = XFER_MW_DMA_0;
 			/* We do need the right mode information for DMA or PIO
 			   and this comes from the current configuration flags */
-			if (dma_enabled & (1 << (5 + i))) {
+			if (ata_id_has_dma(dev->id)) {
 				ata_dev_printk(dev, KERN_INFO, "configured for DMA\n");
 				dev->xfer_mode = XFER_MW_DMA_0;
 				dev->xfer_shift = ATA_SHIFT_MWDMA;
Applied
#1 lore raw
Quoted 13 lines · Bartlomiej Zolnierkiewicz

Code intended to check DMA status was checking DMA command register.

Moreover firmware seems to "forget" to set DMA capable bit for the slave device (at least in RAID mode but without ITE RAID volumes) so check device ID for DMA capable bit when deciding whether to use DMA and remove DMA status check completely.

Thanks to Pavol Simo for the bugreport and testing the initial fix.

This change unfortunately still doesn't fix DMA in RAID mode (which works fine with IDE it821x) but Alan is working on the missing pieces (pata_it821x vs libata EH issues).

Quoted 8 lines
Signed-off-by Bartlomiej Zolnierkiewicz <[email protected]>
Acked-by Alan Cox <[email protected]>
Cc Tejun Heo <[email protected]>

---
removed non-ASCII char from the patch description + added Alan's ACK

 drivers/ata/pata_it821x.c |   11 +++--------
 1 file changed, 3 insertions(+), 8 deletions(-)

applied