Merge tag 'dmaengine-4.15-rc1' of git://git.infradead.org/users/vkoul/slave-dma

[mirror_ubuntu-bionic-kernel.git] / drivers / dma / edma.c

diff --git a/drivers/dma/edma.c b/drivers/dma/edma.c
index 6970355abdc9efc9788b998dc4a54530c78b7609..9364a3ed345a21de9c4c9ce617efedb5d02e4639 100644 (file)
--- a/drivers/dma/edma.c
+++ b/drivers/dma/edma.c
@@ -1147,11 +1147,24 @@ static struct dma_async_tx_descriptor *edma_prep_dma_memcpy(
        struct edma_desc *edesc;
        struct device *dev = chan->device->dev;
        struct edma_chan *echan = to_edma_chan(chan);
-       unsigned int width, pset_len;
+       unsigned int width, pset_len, array_size;
 
        if (unlikely(!echan || !len))
                return NULL;
 
+       /* Align the array size (acnt block) with the transfer properties */
+       switch (__ffs((src | dest | len))) {
+       case 0:
+               array_size = SZ_32K - 1;
+               break;
+       case 1:
+               array_size = SZ_32K - 2;
+               break;
+       default:
+               array_size = SZ_32K - 4;
+               break;
+       }
+
        if (len < SZ_64K) {
                /*
                 * Transfer size less than 64K can be handled with one paRAM
@@ -1173,7 +1186,7 @@ static struct dma_async_tx_descriptor *edma_prep_dma_memcpy(
                 * When the full_length is multibple of 32767 one slot can be
                 * used to complete the transfer.
                 */
-               width = SZ_32K - 1;
+               width = array_size;
                pset_len = rounddown(len, width);
                /* One slot is enough for lengths multiple of (SZ_32K -1) */
                if (unlikely(pset_len == len))
@@ -1221,7 +1234,7 @@ static struct dma_async_tx_descriptor *edma_prep_dma_memcpy(
                }
                dest += pset_len;
                src += pset_len;
-               pset_len = width = len % (SZ_32K - 1);
+               pset_len = width = len % array_size;
 
                ret = edma_config_pset(chan, &edesc->pset[1], src, dest, 1,
                                       width, pset_len, DMA_MEM_TO_MEM);