[PATCH 2/2] dma: pl330: Limit MFIFO usage for memcpy to avoid exhausting entries

From: Jon Medhurst
Date: Fri Nov 07 2014 - 13:39:20 EST


The MFIFO is shared by all channels so restrict each memcpy to it's fair
share. This is being over cautious, but without a global view of DMA
channel usage on a system it's not possible to come up with a more
optimum safe limit.

Signed-off-by: Jon Medhurst <tixy@xxxxxxxxxx>
---
drivers/dma/pl330.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c
index 8f869ec..849439a 100644
--- a/drivers/dma/pl330.c
+++ b/drivers/dma/pl330.c
@@ -2336,7 +2336,7 @@ static inline int get_burst_len(struct dma_pl330_desc *desc, size_t len)
int burst_len;

burst_len = pl330->pcfg.data_bus_width / 8;
- burst_len *= pl330->pcfg.data_buf_dep;
+ burst_len *= pl330->pcfg.data_buf_dep / pl330->pcfg.num_chan;
burst_len >>= desc->rqcfg.brst_size;

/* src/dst_burst_len can't be more than 16 */
--
2.1.1

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