From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: linuxppc-dev list <linuxppc-dev@ozlabs.org>,
Jiri Slaby <jslaby@suse.cz>,
Linux Kernel list <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] tty/hvc/hvc_console: Fix wakeup of HVC thread on hvc_kick()
Date: Wed, 28 May 2014 13:32:48 -0700 [thread overview]
Message-ID: <20140528203248.GA14431@kroah.com> (raw)
In-Reply-To: <1401235290.8262.9.camel@pasglop>
On Wed, May 28, 2014 at 10:01:30AM +1000, Benjamin Herrenschmidt wrote:
> On Fri, 2014-05-23 at 19:41 +1000, Benjamin Herrenschmidt wrote:
> > Some backends call hvc_kick() to wakeup the HVC thread from its
> > slumber upon incoming characters. This however doesn't work
> > properly because it uses msleep_interruptible() which is mostly
> > immune to wake_up_process(). It will basically go back to sleep
> > until the timeout is expired (only signals can really wake it).
> >
> > Replace it with a simple shedule_timeout_interruptible() instead,
> > which may wakeup earlier every now and then but we really don't
> > care in this case.
>
> Nobody commented ? :-)
>
> Greg, do you want to take this in the tty tree or can I stick it in
> powerpc ?
I'll take it, thanks.
greg k-h
WARNING: multiple messages have this Message-ID (diff)
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Jiri Slaby <jslaby@suse.cz>,
Linux Kernel list <linux-kernel@vger.kernel.org>,
linuxppc-dev list <linuxppc-dev@ozlabs.org>
Subject: Re: [PATCH] tty/hvc/hvc_console: Fix wakeup of HVC thread on hvc_kick()
Date: Wed, 28 May 2014 13:32:48 -0700 [thread overview]
Message-ID: <20140528203248.GA14431@kroah.com> (raw)
In-Reply-To: <1401235290.8262.9.camel@pasglop>
On Wed, May 28, 2014 at 10:01:30AM +1000, Benjamin Herrenschmidt wrote:
> On Fri, 2014-05-23 at 19:41 +1000, Benjamin Herrenschmidt wrote:
> > Some backends call hvc_kick() to wakeup the HVC thread from its
> > slumber upon incoming characters. This however doesn't work
> > properly because it uses msleep_interruptible() which is mostly
> > immune to wake_up_process(). It will basically go back to sleep
> > until the timeout is expired (only signals can really wake it).
> >
> > Replace it with a simple shedule_timeout_interruptible() instead,
> > which may wakeup earlier every now and then but we really don't
> > care in this case.
>
> Nobody commented ? :-)
>
> Greg, do you want to take this in the tty tree or can I stick it in
> powerpc ?
I'll take it, thanks.
greg k-h
next prev parent reply other threads:[~2014-05-28 20:29 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-05-23 9:41 [PATCH] tty/hvc/hvc_console: Fix wakeup of HVC thread on hvc_kick() Benjamin Herrenschmidt
2014-05-23 9:41 ` Benjamin Herrenschmidt
2014-05-28 0:01 ` Benjamin Herrenschmidt
2014-05-28 0:01 ` Benjamin Herrenschmidt
2014-05-28 20:32 ` Greg Kroah-Hartman [this message]
2014-05-28 20:32 ` Greg Kroah-Hartman
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