From: Miroslav Lichvar <mlichvar@redhat.com>
To: intel-wired-lan@osuosl.org
Subject: [Intel-wired-lan] [PATCH] igb: protect TX timestamping from API misuse
Date: Tue, 20 Jun 2017 14:55:52 +0200 [thread overview]
Message-ID: <20170620125552.GB10520@localhost> (raw)
In-Reply-To: <20170619203043.120598-1-cspradlin@google.com>
On Mon, Jun 19, 2017 at 01:30:43PM -0700, Cliff Spradlin wrote:
> HW timestamping can only be requested for a packet if the NIC is first
> setup via ioctl(SIOCSHWTSTAMP). If this step was skipped, then the igb
> driver still allowed TX packets to request HW timestamping. In this
> situation, the _IGB_PTP_TX_IN_PROGRESS flag was set and would never
> clear. This prevented any future HW timestamping requests to succeed.
Good catch!
This probably explains some weird cases I saw where HW timestamping
stopped working and the only thing that fixed it was to rmmod &&
modprobe the igb driver. I suspected a faulty HW and it's probably
just me messing with hwstamp_ctl at wrong time.
Thanks,
--
Miroslav Lichvar
next prev parent reply other threads:[~2017-06-20 12:55 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-06-19 20:30 [Intel-wired-lan] [PATCH] igb: protect TX timestamping from API misuse Cliff Spradlin
2017-06-20 12:55 ` Miroslav Lichvar [this message]
2017-06-27 0:53 ` Brown, Aaron F
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