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Message-ID: <472f7fc2d44d781edb64f19f9970fe50eec79c1f.camel@linux.intel.com>
Subject: Re: PNP0501 serial driver takes almost 2 seconds to suspend/resume
 (printk issue)
From:   Todd Brandt <todd.e.brandt@linux.intel.com>
Reply-To: todd.e.brandt@linux.intel.com
To:     John Ogness <john.ogness@linutronix.de>,
        Sergey Senozhatsky <senozhatsky@chromium.org>,
        Petr Mladek <pmladek@suse.com>, rafael.j.wysocki@intel.com,
        len.brown@intel.com
Cc:     Andy Shevchenko <andy.shevchenko@gmail.com>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        "open list:SERIAL DRIVERS" <linux-serial@vger.kernel.org>,
        Steven Rostedt <rostedt@goodmis.org>
Date:   Thu, 14 Jul 2022 15:16:39 -0700
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On Wed, 2022-07-13 at 23:28 +0206, John Ogness wrote:
> On 2022-07-13, Todd Brandt <todd.e.brandt@linux.intel.com> wrote:
> > URGENT: Removing the commit FIXES the issue.
> >=20
> > I just ran a 5.19.0-rc6 kernel with the offending commit removed
> > and
> > it fixed the problem completely on all 3 machines.
>=20
> I believe to have found the issue. A patch was posted to bugzilla:
>=20
> https://bugzilla.kernel.org/attachment.cgi?id=3D301413
>=20
> Please test this. Thanks.
>=20
> John Ogness

I ran with your fix on 30 systems. On the 7 machines where this problem
appears, the patch fixes it completely. On the 23 machines where this
problem does not appear, there are no issues or regressions.

Fix verified, thank you!