Thread (29 messages) 29 messages, 3 authors, 2016-05-09
STALE3683d REVIEWED: 2 (2M)
Revisions (2)
  1. v1 [diff vs current]
  2. v2 current

[PATCH v2 04/23] ata: sata_dwc_460ex: burst size must be in items not bytes

From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Date: 2016-04-26 09:15:41
Also in: linux-ide, lkml
Subsystem: libata subsystem (serial and parallel ata drivers), the rest · Maintainers: Damien Le Moal, Niklas Cassel, Linus Torvalds

The burst size as defined by DMAengine API is in items of address width. Derive
burst size from AHB_DMA_BRST_DFLT (64 bytes) by dividing it to
DMA_SLAVE_BUSWIDTH_4_BYTES (4 bytes) that gives us 16 items.

Tested-by: Christian Lamparter <chunkeey@googlemail.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 drivers/ata/sata_dwc_460ex.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/ata/sata_dwc_460ex.c b/drivers/ata/sata_dwc_460ex.c
index aee8873..4cac27d 100644
--- a/drivers/ata/sata_dwc_460ex.c
+++ b/drivers/ata/sata_dwc_460ex.c
@@ -65,7 +65,7 @@
 #define NO_IRQ		0
 #endif
 
-#define AHB_DMA_BRST_DFLT	64	/* 16 data items burst length*/
+#define AHB_DMA_BRST_DFLT	64	/* 16 data items burst length */
 
 enum {
 	SATA_DWC_MAX_PORTS = 1,
@@ -318,8 +318,8 @@ static struct dma_async_tx_descriptor *dma_dwc_xfer_setup(struct ata_queued_cmd
 	}
 
 	sconf.direction = qc->dma_dir;
-	sconf.src_maxburst = AHB_DMA_BRST_DFLT;
-	sconf.dst_maxburst = AHB_DMA_BRST_DFLT;
+	sconf.src_maxburst = AHB_DMA_BRST_DFLT / 4;	/* in items */
+	sconf.dst_maxburst = AHB_DMA_BRST_DFLT / 4;	/* in items */
 	sconf.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
 	sconf.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
 
-- 
2.8.0.rc3
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