The FEC hardware sometimes errors out on data transfer and hangs in the tightloop adjusted by this patch. So add timeout into the tightloop to make such a hang recoverable.
Signed-off-by: Marek Vasut marex@denx.de Cc: Joe Hershberger joe.hershberger@ni.com Cc: Fabio Estevam festevam@gmail.com Cc: Otavio Salvador otavio@ossystems.com.br Cc: Stefano Babic sbabic@denx.de --- drivers/net/fec_mxc.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-)
diff --git a/drivers/net/fec_mxc.c b/drivers/net/fec_mxc.c index bc44d38..6f071e9 100644 --- a/drivers/net/fec_mxc.c +++ b/drivers/net/fec_mxc.c @@ -35,6 +35,12 @@
DECLARE_GLOBAL_DATA_PTR;
+/* + * Timeout the transfer after 5 mS. This is usually a bit more, since + * the code in the tightloops this timeout is used in adds some overhead. + */ +#define FEC_XFER_TIMEOUT 5000 + #ifndef CONFIG_MII #error "CONFIG_MII has to be defined!" #endif @@ -697,6 +703,8 @@ static int fec_send(struct eth_device *dev, void *packet, int length) unsigned int status; uint32_t size, end; uint32_t addr; + int timeout = FEC_XFER_TIMEOUT; + int ret = 0;
/* * This routine transmits one frame. This routine only accepts @@ -764,6 +772,10 @@ static int fec_send(struct eth_device *dev, void *packet, int length) while (readw(&fec->tbd_base[fec->tbd_index].status) & FEC_TBD_READY) { udelay(1); invalidate_dcache_range(addr, addr + size); + if (!timeout--) { + ret = -EINVAL; + break; + } }
debug("fec_send: status 0x%x index %d\n", @@ -775,7 +787,7 @@ static int fec_send(struct eth_device *dev, void *packet, int length) else fec->tbd_index = 1;
- return 0; + return ret; }
/**