From: Linkui Xiao <[email protected]>
e1000e_config_hwtstamp() stores the requested configuration in
adapter->hwtstamp_config right after the rx filter has been
translated, but the two register writes that follow are verified by
reading the registers back and each of them can fail with -EAGAIN.
When one of them does, the driver is left holding a configuration the
hardware never accepted:
- e1000e_hwtstamp_get() hands it back to user space, so an
application that reads the configuration back is told that
hardware time stamping is in effect while it is not;
- e1000e_systim_reset() re-applies it after every reset, including
the ones the watchdog triggers, and keeps failing;
- e1000_watchdog() starts polling TSYNCRXCTL_VALID for the cached rx
filter, and e1000_xmit_frame() still parks skbs that ask for a Tx
time stamp because it only looks at FLAG_HAS_HW_TIMESTAMP, so they
are eventually dropped by e1000e_tx_hwtstamp_work() with a
"clearing Tx timestamp hang" warning.
Cache the configuration only once both registers have been verified,
so that adapter->hwtstamp_config always describes what the hardware
is programmed with.
Fixes: 62d7e3a2d006 ("e1000e: Validate hwtstamp_config completely before
applying it")
Cc: [email protected]
Signed-off-by: Linkui Xiao <[email protected]>
---
drivers/net/ethernet/intel/e1000e/netdev.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c
b/drivers/net/ethernet/intel/e1000e/netdev.c
index 35f5590228eb..7ae33273734f 100644
--- a/drivers/net/ethernet/intel/e1000e/netdev.c
+++ b/drivers/net/ethernet/intel/e1000e/netdev.c
@@ -3715,8 +3715,6 @@ static int e1000e_config_hwtstamp(struct e1000_adapter
*adapter,
return -ERANGE;
}
- adapter->hwtstamp_config = *config;
-
/* enable/disable Tx h/w time stamping */
regval = er32(TSYNCTXCTL);
regval &= ~E1000_TSYNCTXCTL_ENABLED;
@@ -3763,6 +3761,8 @@ static int e1000e_config_hwtstamp(struct e1000_adapter
*adapter,
er32(RXSTMPH);
er32(TXSTMPH);
+ adapter->hwtstamp_config = *config;
+
return 0;
}
--
2.25.1
