diff options
Diffstat (limited to 'drivers/dma')
| -rw-r--r-- | drivers/dma/pl330.c | 17 |
1 files changed, 13 insertions, 4 deletions
diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c index 4839bfa74a10..81505420bde4 100644 --- a/drivers/dma/pl330.c +++ b/drivers/dma/pl330.c @@ -2459,16 +2459,25 @@ pl330_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dst, /* Select max possible burst size */ burst = pl330->pcfg.data_bus_width / 8; - while (burst > 1) { - if (!(len % burst)) - break; + /* + * Make sure we use a burst size that aligns with all the memcpy + * parameters because our DMA programming algorithm doesn't cope with + * transfers which straddle an entry in the DMA device's MFIFO. + */ + while ((src | dst | len) & (burst - 1)) burst /= 2; - } desc->rqcfg.brst_size = 0; while (burst != (1 << desc->rqcfg.brst_size)) desc->rqcfg.brst_size++; + /* + * If burst size is smaller than bus width then make sure we only + * transfer one at a time to avoid a burst stradling an MFIFO entry. + */ + if (desc->rqcfg.brst_size * 8 < pl330->pcfg.data_bus_width) + desc->rqcfg.brst_len = 1; + desc->rqcfg.brst_len = get_burst_len(desc, len); desc->txd.flags = flags; |
