spi/pl022: pass the returned sglen to the DMA engine

The sglen return by the dma_map_sg() should be passed to the DMA
engine, not the one passed in. If we one day have a DMA mapper
that can coalesce entries, this will bug due to a too large
number of entries being passed in.

Reported-by: Russell King <linux@arm.linux.org.uk>
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

diff --git a/drivers/spi/amba-pl022.c b/drivers/spi/amba-pl022.c
index e29751a..36ec132 100644 (file)
--- a/drivers/spi/amba-pl022.c
+++ b/drivers/spi/amba-pl022.c
@@ -917,7 +917,7 @@ static int configure_dma(struct pl022 *pl022)
        };
        unsigned int pages;
        int ret;
-       int sglen;
+       int rx_sglen, tx_sglen;
        struct dma_chan *rxchan = pl022->dma_rx_channel;
        struct dma_chan *txchan = pl022->dma_tx_channel;
        struct dma_async_tx_descriptor *rxdesc;
@@ -991,20 +991,20 @@ static int configure_dma(struct pl022 *pl022)
                          pl022->cur_transfer->len, &pl022->sgt_tx);
 
        /* Map DMA buffers */
-       sglen = dma_map_sg(rxchan->device->dev, pl022->sgt_rx.sgl,
+       rx_sglen = dma_map_sg(rxchan->device->dev, pl022->sgt_rx.sgl,
                           pl022->sgt_rx.nents, DMA_FROM_DEVICE);
-       if (!sglen)
+       if (!rx_sglen)
                goto err_rx_sgmap;
 
-       sglen = dma_map_sg(txchan->device->dev, pl022->sgt_tx.sgl,
+       tx_sglen = dma_map_sg(txchan->device->dev, pl022->sgt_tx.sgl,
                           pl022->sgt_tx.nents, DMA_TO_DEVICE);
-       if (!sglen)
+       if (!tx_sglen)
                goto err_tx_sgmap;
 
        /* Send both scatterlists */
        rxdesc = rxchan->device->device_prep_slave_sg(rxchan,
                                      pl022->sgt_rx.sgl,
-                                     pl022->sgt_rx.nents,
+                                     rx_sglen,
                                      DMA_FROM_DEVICE,
                                      DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
        if (!rxdesc)
@@ -1012,7 +1012,7 @@ static int configure_dma(struct pl022 *pl022)
 
        txdesc = txchan->device->device_prep_slave_sg(txchan,
                                      pl022->sgt_tx.sgl,
-                                     pl022->sgt_tx.nents,
+                                     tx_sglen,
                                      DMA_TO_DEVICE,
                                      DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
        if (!txdesc)