From: Russell King - ARM Linux <linux@arm.linux.org.uk>
Date: Mon, 3 Jan 2011 22:42:55 +0000 (+0000)
Subject: ARM: PL08x: fix fill_bytes calculation
X-Git-Tag: Ubuntu-5.2.0-15.16~22262^2~11^2~10
X-Git-Url: https://git.proxmox.com/?a=commitdiff_plain;h=5f638b4f313e345bf02700910e581bccf71212f5;p=mirror_ubuntu-eoan-kernel.git

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>
---

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);