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 <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>
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 @@
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 @@
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 @@
else
fec->tbd_index = 1;
- return 0;
+ return ret;
}
/**