Subject: Re: [Intel-wired-lan] [PATCH net] ixgbe: fix timestamp configuration code

From: Vadim Fedorenko <[email-masked]>
Date: Thu, 31 Aug 2023 08:50:42 -0400

On 31/08/2023 06:18, Pucha, HimasekharX Reddy wrote:
>> -----Original Message-----
>> From: Intel-wired-lan <[email-masked]> On Behalf Of Vadim Fedorenko
>> Sent: Thursday, August 24, 2023 3:46 AM
>> To: Brandeburg, Jesse <[email-masked]>; Nguyen, Anthony L <[email-masked]>; Jakub Kicinski <[email-masked]>; Alexander Duyck <[email-masked]>; Rustad, Mark D <[email-masked]>; Darin Miller <[email-masked]>; Jeff Kirsher <[email-masked]>; Richard Cochran <[email-masked]>
>> Cc: [email-masked]; [email-masked]; Vadim Fedorenko <[email-masked]>
>> Subject: [Intel-wired-lan] [PATCH net] ixgbe: fix timestamp configuration code
>>
>> The commit in fixes introduced flags to control the status of hardware
>> configuration while processing packets. At the same time another structure
>> is used to provide configuration of timestamper to user-space applications.
>> The way it was coded makes this structures go out of sync easily. The
>> repro is easy for 82599 chips:
>>
>> [root@hostname ~]# hwstamp_ctl -i eth0 -r 12 -t 1
>> current settings:
>> tx_type 0
>> rx_filter 0
>> new settings:
>> tx_type 1
>> rx_filter 12
>>
>> The eth0 device is properly configured to timestamp any PTPv2 events.
>>
>> [root@hostname ~]# hwstamp_ctl -i eth0 -r 1 -t 1
>> current settings:
>> tx_type 1
>> rx_filter 12
>> SIOCSHWTSTAMP failed: Numerical result out of range
>> The requested time stamping mode is not supported by the hardware.
>>
>> The error is properly returned because HW doesn't support all packets
>> timestamping. But the adapter->flags is cleared of timestamp flags
>> even though no HW configuration was done. From that point no RX timestamps
>> are received by user-space application. But configuration shows good
>> values:
>>
>> [root@hostname ~]# hwstamp_ctl -i eth0
>> current settings:
>> tx_type 1
>> rx_filter 12
>>
>> Fix the issue by applying new flags only when the HW was actually
>> configured.
>>
>> Fixes: a9763f3cb54c ("ixgbe: Update PTP to support X550EM_x devices")
>> Signed-off-by: Vadim Fedorenko <[email-masked]>
>> ---
>>   drivers/net/ethernet/intel/ixgbe/ixgbe_ptp.c | 28 +++++++++++---------
>>   1 file changed, 15 insertions(+), 13 deletions(-)
>>
> 
> Hi,
> With patch also we are observing same issue.

Hi,

What kind of issue do you observe? The hardware doesn't support
timestamping of all packets. The issue this patch fixes is that
after failed attempt to setup the timestamping of all RX packets,
the driver stops reading timestamps at all even though it reports
that timestamping of PTP RX packets is enabled.

> 
> # ./hwstamp_ctl -i eth10
> current settings:
> tx_type 1
> rx_filter 12
> # ./hwstamp_ctl -i eth10 -r 1 -t 1
> current settings:
> tx_type 1
> rx_filter 12
> SIOCSHWTSTAMP failed: Numerical result out of range
> The requested time stamping mode is not supported by the hardware.
> 
> Adapter details: Niantic (Spring Fountain)
> 
> SUT info:
> H/W:
>    Manufacturer: Intel Corporation
>    Product Name: S2600STQ
>    RAM: [62G/8G/49G]
>    CPU: Intel(R) Xeon(R) Platinum 8180 CPU @ 2.50GHz [112/112]
>    PF bus-info: 0000:d8:00.1 0x8086:0x10fb 0x8086 0x000c (0x01)
> S/W:
>    OS: "Red Hat Enterprise Linux 8.6 (Ootpa)" 6.5.0-rc7_next-queue_28-Aug-2023-01755-g938672aefaeb
>    CMD: BOOT_IMAGE=(hd0,msdos2)/vmlinuz-6.5.0-rc7_next-queue_28-Aug-2023-01755-g938672aefaeb root=/dev/mapper/rhel_os--delivery-root ro crashkernel=1G-4G:192M,4G-64G:256M,64G-:512M resume=/dev/mapper/rhel_os--delivery-swap rd.lvm.lv=rhel_os-delivery/root rd.lvm.lv=rhel_os-delivery/swap selinux=0 biosdevname=0 net.ifnames=0 rhgb quiet
>    FW firmware-version: 0x000161bf
>    PF version: 6.5.0-rc7_next-queue_28-Aug-202
> 
>