From bc1ce150b95bc51390add7fb8b74c535d1b5673c Mon Sep 17 00:00:00 2001 From: Marek Vasut Date: Wed, 29 Aug 2012 03:49:49 +0000 Subject: [PATCH] FEC: Remove endless loop in the FEC driver 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 Cc: Joe Hershberger Cc: Fabio Estevam Cc: Otavio Salvador Cc: Stefano Babic --- 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 bc44d38b42..6f071e9414 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; } /** -- 2.39.5