I've noticed that the first ethernet packet after PHY link establishment is not tranferred correctly most of the time on my AT91SAM9G25 board. Here I usually see a timeout of a few seconds, which is quite annoying.
Adding a small delay (10ms in this case) after the link establishment helps to solve this problem. With this patch applied, this timeout on the first packet is not seen any more.
Signed-off-by: Stefan Roese sr@denx.de Cc: Wenyou Yang wenyou.yang@atmel.com Cc: Eugen Hristev eugen.hristev@microchip.com Cc: Joe Hershberger joe.hershberger@ni.com --- drivers/net/macb.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/drivers/net/macb.c b/drivers/net/macb.c index 182331f61d..72614164e9 100644 --- a/drivers/net/macb.c +++ b/drivers/net/macb.c @@ -550,8 +550,14 @@ static int macb_phy_init(struct macb_device *macb, const char *name)
for (i = 0; i < MACB_AUTONEG_TIMEOUT / 100; i++) { status = macb_mdio_read(macb, MII_BMSR); - if (status & BMSR_LSTATUS) + if (status & BMSR_LSTATUS) { + /* + * Delay a bit after the link is established, + * so that the next xfer does not fail + */ + mdelay(10); break; + } udelay(100); } }