[U-Boot] [PATCH v7 1/2] net: fec_mxc: Adjust RX DMA alignment for mx6solox

Fabio Estevam
2014-08-25T16:34:16Z

mx6solox has a requirement for 64 bytes alignment for RX DMA transfer.
Other SoCs work with the standard 32 bytes alignment.

Adjust it accordingly by using 64 bytes aligment in the FEC RX DMA buffers,
which addresses the needs from mx6solox and also works for the other SoCs.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
---
Changes since v6:
- Only use FEC_DMA_RX_MINALIGN for the RX buffers
Changes since v5:
- Add Stefan's Ack
Changes since v4:
- None

Signed-off-by: Fabio Estevam <festevam@gmail.com>
---
drivers/net/fec_mxc.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/drivers/net/fec_mxc.c b/drivers/net/fec_mxc.c
index 4cefda4..d310016 100644
--- a/drivers/net/fec_mxc.c
+++ b/drivers/net/fec_mxc.c
@@ -28,6 +28,14 @@ DECLARE_GLOBAL_DATA_PTR;
*/
#define FEC_XFER_TIMEOUT 5000

+/*
+ * The standard 32-byte DMA alignment does not work on mx6solox, which requires
+ * 64-byte alignment in the DMA RX FEC buffer.
+ * Introduce the FEC_DMA_RX_MINALIGN which can cover mx6solox needs and also
+ * satisfies the alignment on other SoCs (32-bytes)
+ */
+#define FEC_DMA_RX_MINALIGN 64
+
#ifndef CONFIG_MII
#error "CONFIG_MII has to be defined!"
#endif
@@ -881,9 +889,9 @@ static int fec_alloc_descs(struct fec_priv *fec)
/* Allocate RX buffers. */

/* Maximum RX buffer size. */
- size = roundup(FEC_MAX_PKT_SIZE, ARCH_DMA_MINALIGN);
+ size = roundup(FEC_MAX_PKT_SIZE, FEC_DMA_RX_MINALIGN);
for (i = 0; i < FEC_RBD_NUM; i++) {
- data = memalign(ARCH_DMA_MINALIGN, size);
+ data = memalign(FEC_DMA_RX_MINALIGN, size);
if (!data) {
printf("%s: error allocating rxbuf %d\n", __func__, i);
goto err_ring;
--
1.9.1