spi/dw_spi: refine the IRQ mode working flow

Now dw_spi core fully supports 3 transfer modes: pure polling,
DMA and IRQ mode. IRQ mode will use the FIFO half empty as
the IRQ trigger, so each interface driver need set the fifo_len,
so that core driver can handle it properly

Signed-off-by: Feng Tang <feng.tang@intel.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

1 files changed, 1 insertions, 0 deletions

diff --git a/drivers/spi/dw_spi_pci.c b/drivers/spi/dw_spi_pci.c
index 7980f1443ce1..1f0735f9cc76 100644
--- a/drivers/spi/dw_spi_pci.c
+++ b/drivers/spi/dw_spi_pci.c
@@ -73,6 +73,7 @@ static int __devinit spi_pci_probe(struct pci_dev *pdev,
         dws->num_cs = 4;
         dws->max_freq = 25000000;       /* for Moorestwon */
         dws->irq = pdev->irq;
+        dws->fifo_len = 40;             /* FIFO has 40 words buffer */
 
         ret = dw_spi_add_host(dws);
         if (ret)