net: fec_mxc: Fix timeouts during tftp transfer

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@digi.com>
Tested-by: Oliver Metz <oliver@freetz.org>
Tested-by: Hector Palacios <hector.palacios@digi.com>
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Acked-by: Marek Vasut <marex@denx.de>
Tested-by: Marek Vasut <marex@denx.de>

diff --git a/drivers/net/fec_mxc.c b/drivers/net/fec_mxc.c
index 210ef02df53dbf9ba332e91c3b428b981807342d..107cd6ecc5c3b25a5b173faba25f1e2f76b26b50 100644 (file)
--- 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