[PATCH 4.9] ixgbe: prevent ptp_rx_hang from running when in FILTER_ALL mode

[PATCH 4.9] ixgbe: prevent ptp_rx_hang from running when in FILTER_ALL mode

[Wen Yang]

From: Jacob Keller <jacob.e.keller@intel.com>

commit 6704a3abf4cf4181a1ee64f5db4969347b88ca1d upstream.

On hardware which supports timestamping all packets, the timestamps are
recorded in the packet buffer, and the driver no longer uses or reads
the registers. This makes the logic for checking and clearing Rx
timestamp hangs meaningless.

If we run the ixgbe_ptp_rx_hang() function in this case, then the driver
will continuously spam the log output with "Clearing Rx timestamp hang".
These messages are spurious, and confusing to end users.

The original code in commit a9763f3cb54c ("ixgbe: Update PTP to support
X550EM_x devices", 2015-12-03) did have a flag PTP_RX_TIMESTAMP_IN_REGISTER
which was intended to be used to avoid the Rx timestamp hang check,
however it did not actually check the flag before calling the function.

Do so now in order to stop the checks and prevent the spurious log
messages.

Fixes: a9763f3cb54c ("ixgbe: Update PTP to support X550EM_x devices", 2015-12-03)
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Cc: <stable@vger.kernel.org> # 4.9.x: 622a2ef538fb: ixgbe: check for Tx timestamp timeouts during watchdog
Cc: <stable@vger.kernel.org> # 4.9.x
Signed-off-by: Wen Yang <wenyang@linux.alibaba.com>
---
 drivers/net/ethernet/intel/ixgbe/ixgbe_main.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
index 66b1cc02..36d73bf 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
@@ -7257,7 +7257,8 @@ static void ixgbe_service_task(struct work_struct *work)
 
 	if (test_bit(__IXGBE_PTP_RUNNING, &adapter->state)) {
 		ixgbe_ptp_overflow_check(adapter);
-		ixgbe_ptp_rx_hang(adapter);
+		if (adapter->flags & IXGBE_FLAG_RX_HWTSTAMP_IN_REGISTER)
+			ixgbe_ptp_rx_hang(adapter);
 		ixgbe_ptp_tx_hang(adapter);
 	}
 
-- 
1.8.3.1

Re: [PATCH 4.9] ixgbe: prevent ptp_rx_hang from running when in FILTER_ALL mode

[Greg Kroah-Hartman]

On Sat, Mar 20, 2021 at 09:44:51AM +0800, Wen Yang wrote:
> From: Jacob Keller <jacob.e.keller@intel.com>
> 
> commit 6704a3abf4cf4181a1ee64f5db4969347b88ca1d upstream.
> 
> On hardware which supports timestamping all packets, the timestamps are
> recorded in the packet buffer, and the driver no longer uses or reads
> the registers. This makes the logic for checking and clearing Rx
> timestamp hangs meaningless.
> 
> If we run the ixgbe_ptp_rx_hang() function in this case, then the driver
> will continuously spam the log output with "Clearing Rx timestamp hang".
> These messages are spurious, and confusing to end users.
> 
> The original code in commit a9763f3cb54c ("ixgbe: Update PTP to support
> X550EM_x devices", 2015-12-03) did have a flag PTP_RX_TIMESTAMP_IN_REGISTER
> which was intended to be used to avoid the Rx timestamp hang check,
> however it did not actually check the flag before calling the function.
> 
> Do so now in order to stop the checks and prevent the spurious log
> messages.
> 
> Fixes: a9763f3cb54c ("ixgbe: Update PTP to support X550EM_x devices", 2015-12-03)
> Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
> Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
> Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
> Cc: <stable@vger.kernel.org> # 4.9.x: 622a2ef538fb: ixgbe: check for Tx timestamp timeouts during watchdog
> Cc: <stable@vger.kernel.org> # 4.9.x
> Signed-off-by: Wen Yang <wenyang@linux.alibaba.com>
> ---
>  drivers/net/ethernet/intel/ixgbe/ixgbe_main.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)

Thanks for the backport, now queued up.

greg k-h