[v4.4.y,v4.9.y] igb: Remove incorrect "unexpected SYS WRAP" log message

From: Corinna Vinschen <vinschen@redhat.com>

commit 2643e6e90210e16c978919617170089b7c2164f7 upstream

TSAUXC.DisableSystime is never set, so SYSTIM runs into a SYS WRAP
every 1100 secs on 80580/i350/i354 (40 bit SYSTIM) and every 35000
secs on 80576 (45 bit SYSTIM).

This wrap event sets the TSICR.SysWrap bit unconditionally.

However, checking TSIM at interrupt time shows that this event does not
actually cause the interrupt.  Rather, it's just bycatch while the
actual interrupt is caused by, for instance, TSICR.TXTS.

The conclusion is that the SYS WRAP is actually expected, so the
"unexpected SYS WRAP" message is entirely bogus and just helps to
confuse users.  Drop it.

Signed-off-by: Corinna Vinschen <vinschen@redhat.com>
Acked-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
---
[ Due to confusion about stable rules for networking the request was
mistakenly sent to netdev only[0]. Apologies if you're seeing this
again. ]

Hi,

A customer reported that the following message appears in the kernel
logs every 1100s -

    igb 0000:01:00.1: unexpected SYS WRAP

As the systems have large uptimes the messages are crowding the logs.

The message was dropped in 
commit 2643e6e90210e16c ("igb: Remove incorrect "unexpected SYS WRAP" log message")
in v4.14.

Please consider applying to patch to v4.4 and v4.9 stable kernels - it
applies cleanly to both the trees.

Thanks,
Punit

[0] https://lore.kernel.org/netdev/20210210013448.2116413-1-punit1.agrawal@toshiba.co.jp/

 drivers/net/ethernet/intel/igb/igb_main.c | 2 --
 1 file changed, 2 deletions(-)

Hi Greg,

Greg KH <greg@kroah.com> writes:

> On Thu, Feb 25, 2021 at 09:54:06AM +0900, Punit Agrawal wrote:

>> From: Corinna Vinschen <vinschen@redhat.com>

>> 

>> commit 2643e6e90210e16c978919617170089b7c2164f7 upstream

>> 

>> TSAUXC.DisableSystime is never set, so SYSTIM runs into a SYS WRAP

>> every 1100 secs on 80580/i350/i354 (40 bit SYSTIM) and every 35000

>> secs on 80576 (45 bit SYSTIM).

>> 

>> This wrap event sets the TSICR.SysWrap bit unconditionally.

>> 

>> However, checking TSIM at interrupt time shows that this event does not

>> actually cause the interrupt.  Rather, it's just bycatch while the

>> actual interrupt is caused by, for instance, TSICR.TXTS.

>> 

>> The conclusion is that the SYS WRAP is actually expected, so the

>> "unexpected SYS WRAP" message is entirely bogus and just helps to

>> confuse users.  Drop it.

>> 

>> Signed-off-by: Corinna Vinschen <vinschen@redhat.com>

>> Acked-by: Jacob Keller <jacob.e.keller@intel.com>

>> Tested-by: Aaron Brown <aaron.f.brown@intel.com>

>> Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

>> ---

>> [ Due to confusion about stable rules for networking the request was

>> mistakenly sent to netdev only[0]. Apologies if you're seeing this

>> again. ]

>

> No signed-off-by: from you?  :(


Apologies for the missing the SoB. And thank you for applying the patch
to stable even so.

[ Sorry for the long dealy in responding. Our mail system was having
issues (dropping emails randomly) and looks like this mail got caught up
during that period. ]