gianfar: Implement workaround for eTSEC-A002 erratum
MPC8313ECE says:
"If the controller receives a 1- or 2-byte frame (such as an illegal
runt packet or a packet with RX_ER asserted) before GRS is asserted
and does not receive any other frames, the controller may fail to set
GRSC even when the receive logic is completely idle. Any subsequent
receive frame that is larger than two bytes will reset the state so
the graceful stop can complete. A MAC receiver (Rx) reset will also
reset the state."
This patch implements the proposed workaround:
"If IEVENT[GRSC] is still not set after the timeout, read the eTSEC
register at offset 0xD1C. If bits 7-14 are the same as bits 23-30,
the eTSEC Rx is assumed to be idle and the Rx can be safely reset.
If the register fields are not equal, wait for another timeout
period and check again."
Signed-off-by: Anton Vorontsov <avorontsov@mvista.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/gianfar.h b/drivers/net/gianfar.h
index c414374..710810e 100644
--- a/drivers/net/gianfar.h
+++ b/drivers/net/gianfar.h
@@ -1028,6 +1028,7 @@
enum gfar_errata {
GFAR_ERRATA_74 = 0x01,
GFAR_ERRATA_76 = 0x02,
+ GFAR_ERRATA_A002 = 0x04,
};
/* Struct stolen almost completely (and shamelessly) from the FCC enet source