On 28/10/2026 09:04, Linkui Xiao wrote:
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; }
Reviewed-by: Vadim Fedorenko <[email protected]>
