From: David Laight <David.Laight@ACULAB.COM>
To: "'jeffrey.t.kirsher@intel.com'" <jeffrey.t.kirsher@intel.com>,
"Network Development" <netdev@vger.kernel.org>,
intel-wired-lan <intel-wired-lan@lists.osuosl.org>
Cc: "'bruce.w.allan@intel.com'" <bruce.w.allan@intel.com>,
"'jeffrey.e.pieper@intel.com'" <jeffrey.e.pieper@intel.com>
Subject: RE: [PATCH net 1/1] e1000e: Stop tx/rx setup spinning for upwards of 300us.
Date: Thu, 26 Mar 2020 11:08:52 +0000 [thread overview]
Message-ID: <ed99e7c34aab4b0fafa20fc449e77510@AcuMS.aculab.com> (raw)
In-Reply-To: <c84d4055e13f30edf7b79086c9ed8d7d1fe6523b.camel@intel.com>
From: Jeff Kirsher
> Sent: 04 March 2020 18:04
> On Tue, 2020-03-03 at 17:06 +0000, David Laight wrote:
> > Instead of spinning waiting for the ME to be idle defer the ring
> > tail updates until one of the following:
> > - The next update for that ring.
> > - The receive frame processing.
> > - The next timer tick.
> >
> > Reduce the delay between checks for the ME being idle from 50us
> > to uus.
> >
> > Part fix for bdc125f7.
> >
> > Signed-off-by: David Laight <david.laight@aculab.com>
>
> Added intel-wired-lan@lists.osuosl.org mailing list, so the right
> people can review your patch.
I don't see any sign of anyone looking at this.
Is the code so bad everyone has buried their head in the sand?
Am I right in thinking that the actual hardware problem is
that PCIe writes are 'posted' in the hardware and then lost
if the ME does a write while the PCIe write is still pending?
In which case a much simpler patch that does a readback after
every write and retries if the value is different will solve
the problem without ever needing a delay().
The only 'problem' register would be the interrupt mask
which the hardware appears to change itself.
David
-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)
prev parent reply other threads:[~2020-03-26 11:08 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-03 17:06 [PATCH net 1/1] e1000e: Stop tx/rx setup spinning for upwards of 300us David Laight
2020-03-04 0:02 ` David Miller
2020-03-04 9:44 ` David Laight
2020-03-04 18:03 ` Jeff Kirsher
2020-03-26 11:08 ` David Laight [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=ed99e7c34aab4b0fafa20fc449e77510@AcuMS.aculab.com \
--to=david.laight@aculab.com \
--cc=bruce.w.allan@intel.com \
--cc=intel-wired-lan@lists.osuosl.org \
--cc=jeffrey.e.pieper@intel.com \
--cc=jeffrey.t.kirsher@intel.com \
--cc=netdev@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).