forcedeth: prevent TX timeouts after reboot
This complements patch "net-forcedeth: fix TX timeout caused by TX
pause on down link" which ensures that a lock-up sequence is not sent
to the NIC. Present patch ensures that if a NIC is already locked-up,
the driver will recover from it when initializing the device.
It does the equivalent of the following recovery sequence:
- write NVREG_TX_PAUSEFRAME_ENABLE_V1 to eth1's register
NvRegTxPauseFrame
- write NVREG_XMITCTL_START to eth1's register
NvRegTransmitterControl
- write 0 to eth1's register NvRegTransmitterControl
(this is at the heart of the "unbricking" sequence mentioned in patch
"net-forcedeth: fix TX timeout caused by TX pause on down link")
Tested:
- hardware is MCP55 device id 10de:0373 (rev a3), dual-port
- reboot a kernel without any of patches mentioned
- freeze the NIC (details on description for commit "net-forcedeth:
fix TX timeout caused by TX pause on down link")
- wait 5mn until ping hangs & TX timeout in dmesg
- reboot on kernel with present patch
- host is immediatly operational, no TX timeout
Signed-off-by: David Decotigny <decot@googlers.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/nvidia/forcedeth.c b/drivers/net/ethernet/nvidia/forcedeth.c
index 8b82457..876bece 100644
--- a/drivers/net/ethernet/nvidia/forcedeth.c
+++ b/drivers/net/ethernet/nvidia/forcedeth.c
@@ -5905,11 +5905,19 @@
goto out_error;
}
+ netif_carrier_off(dev);
+
+ /* Some NICs freeze when TX pause is enabled while NIC is
+ * down, and this stays across warm reboots. The sequence
+ * below should be enough to recover from that state.
+ */
+ nv_update_pause(dev, 0);
+ nv_start_tx(dev);
+ nv_stop_tx(dev);
+
if (id->driver_data & DEV_HAS_VLAN)
nv_vlan_mode(dev, dev->features);
- netif_carrier_off(dev);
-
dev_info(&pci_dev->dev, "ifname %s, PHY OUI 0x%x @ %d, addr %pM\n",
dev->name, np->phy_oui, np->phyaddr, dev->dev_addr);