Blackfin SPI Driver: pass DMA overflow error to the higher level

If the SPI bus registers a receive overflow error, pass the result back up
to the higher levels.

Signed-off-by: Mike Frysinger <vapier.adi@gmail.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 11 insertions, 5 deletions

diff --git a/drivers/spi/spi_bfin5xx.c b/drivers/spi/spi_bfin5xx.c
index 6d3f6064871e..2e0c024bbde7 100644
--- a/drivers/spi/spi_bfin5xx.c
+++ b/drivers/spi/spi_bfin5xx.c
@@ -559,6 +559,7 @@ static irqreturn_t dma_irq_handler(int irq, void *dev_id)
         struct driver_data *drv_data = dev_id;
         struct chip_data *chip = drv_data->cur_chip;
         struct spi_message *msg = drv_data->cur_msg;
+        u16 spistat = read_STAT(drv_data);
 
         dev_dbg(&drv_data->pdev->dev, "in dma_irq_handler\n");
         clear_dma_irqstat(drv_data->dma_channel);
@@ -582,13 +583,18 @@ static irqreturn_t dma_irq_handler(int irq, void *dev_id)
         while (!(read_STAT(drv_data) & SPIF))
                 cpu_relax();
 
-        msg->actual_length += drv_data->len_in_bytes;
+        if (spistat & RBSY) {
+                msg->state = ERROR_STATE;
+                dev_err(&drv_data->pdev->dev, "dma receive: fifo/buffer overflow\n");
+        } else {
+                msg->actual_length += drv_data->len_in_bytes;
 
-        if (drv_data->cs_change)
-                cs_deactive(drv_data, chip);
+                if (drv_data->cs_change)
+                        cs_deactive(drv_data, chip);
 
-        /* Move to next transfer */
-        msg->state = next_transfer(drv_data);
+                /* Move to next transfer */
+                msg->state = next_transfer(drv_data);
+        }
 
         /* Schedule transfer tasklet */
         tasklet_schedule(&drv_data->pump_transfers);