On 27.03.2019 12:20, Stefan Roese wrote:
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.
Hi Stefan,
I find this a bit odd... maybe someone with a different board having this Ethernet controller can confirm or infirm this ? Linux driver for macb has a similar issue ? Adding a delay just for the sake of it might hide another issue that we are missing at this point: why exactly transfer fails right away... it is likely that we want to send packets but link in fact is not ready ? Or any reason why the packet is not correctly transferred? Do you see errors on the line or the packet vanishes completely ? What kind of packet is this first one ? Does it depend on the packet type ?
Sorry for maybe asking too many questions.
I have added Nicolas and Claudiu who have more experience with macb on at91 boards
Thanks, Eugen
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);