[U-Boot] [PATCH v2] net: fec_mxc: Fix timeouts during tftp transfer

[Fabio Estevam]

From: Fabio Estevam <fabio.estevam at freescale.com>

Performing tftp transfers on mx28 results in random timeouts.

Hector Palacios and Robert Hodaszi analyzed the root cause being related to the 
wrong alignment of the 'buff' buffer inside fec_recv().

Benoît Thébaudeau provided an excellent analysis of the alignment bug that is
present on older versions, such as GCC 4.5.4:

http://marc.info/?l=u-boot&m=137942904906131&w=2 

Use ALLOC_CACHE_ALIGN_BUFFER() to avoid alignment issues from older GCC 
versions.

Reported-by: Hector Palacios <hector.palacios at digi.com>
Tested-by: Oliver Metz <oliver at freetz.org>
Tested-by: Hector Palacios <hector.palacios at digi.com>
Signed-off-by: Fabio Estevam <fabio.estevam at freescale.com>
---
Changes since v1:
- Improve commit log
- Add Hector's Tested-by tag

 drivers/net/fec_mxc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/fec_mxc.c b/drivers/net/fec_mxc.c
index 690e572..b423ff6 100644
--- a/drivers/net/fec_mxc.c
+++ b/drivers/net/fec_mxc.c
@@ -794,7 +794,7 @@ static int fec_recv(struct eth_device *dev)
 	uint16_t bd_status;
 	uint32_t addr, size, end;
 	int i;
-	uchar buff[FEC_MAX_PKT_SIZE] __aligned(ARCH_DMA_MINALIGN);
+	ALLOC_CACHE_ALIGN_BUFFER(uchar, buff, FEC_MAX_PKT_SIZE);
 
 	/*
 	 * Check if any critical events have happened
-- 
1.8.1.2