ARM: PL08x: fix fill_bytes calculation

The number of bytes we want to fill into any LLI is the minimum of:
- number of bytes remaining in the transfer
- number of bytes we can transfer in a single LLI
- number of bytes we can transfer without overflowing the source boundary
- number of bytes we can transfer without overflowing the destination boundary

The minimum of the first two is already calculated (target_len).  We
limit the boundary calculations to this number of bytes, which will
then give us the number of bytes we can place into this LLI.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

1 files changed, 10 insertions, 16 deletions

diff --git a/drivers/dma/amba-pl08x.c b/drivers/dma/amba-pl08x.c
index 91dd6bfcc30f..be7fa174d6c0 100644
--- a/drivers/dma/amba-pl08x.c
+++ b/drivers/dma/amba-pl08x.c
@@ -685,31 +685,25 @@ static int pl08x_fill_llis_for_desc(struct pl08x_driver_data *pl08x,
                         target_len = min(remainder, max_bytes_per_lli);
 
                         /*
-                         * Set bus lengths for incrementing buses
-                         * to number of bytes which fill to next memory
-                         * boundary
+                         * Set bus lengths for incrementing buses to the
+                         * number of bytes which fill to next memory boundary,
+                         * limiting on the target length calculated above.
                          */
                         if (cctl & PL080_CONTROL_SRC_INCR)
                                 txd->srcbus.fill_bytes =
-                                        pl08x_pre_boundary(
-                                                txd->srcbus.addr,
-                                                remainder);
+                                        pl08x_pre_boundary(txd->srcbus.addr,
+                                                target_len);
                         else
-                                txd->srcbus.fill_bytes =
-                                        max_bytes_per_lli;
+                                txd->srcbus.fill_bytes = target_len;
 
                         if (cctl & PL080_CONTROL_DST_INCR)
                                 txd->dstbus.fill_bytes =
-                                        pl08x_pre_boundary(
-                                                txd->dstbus.addr,
-                                                remainder);
+                                        pl08x_pre_boundary(txd->dstbus.addr,
+                                                target_len);
                         else
-                                txd->dstbus.fill_bytes =
-                                                max_bytes_per_lli;
+                                txd->dstbus.fill_bytes = target_len;
 
-                        /*
-                         *  Find the nearest
-                         */
+                        /* Find the nearest */
                         lli_len = min(txd->srcbus.fill_bytes,
                                 txd->dstbus.fill_bytes);