From: Dave.Martin@arm.com (Dave P Martin)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] serial/amba-pl011: Disable interrupts around TX softirq
Date: Mon, 15 Jun 2015 11:53:08 +0100 [thread overview]
Message-ID: <20150615105308.GA3649@e103592.cambridge.arm.com> (raw)
In-Reply-To: <20150613003945.GA10941@kroah.com>
On Sat, Jun 13, 2015 at 01:39:45AM +0100, Greg Kroah-Hartman wrote:
> On Fri, Jun 05, 2015 at 03:07:47PM +0100, Dave Martin wrote:
> > pl011_tx_softirq() currently uses spin_{,un}lock(), which are not
> > sufficient to inhibit pl011_int() from being triggered by a local
> > IRQ and trying to re-take the same lock. This can lead to
> > deadlocks.
> >
> > This patch uses the _irq() locking variants instead to ensure that
> > pl011_int() handling for a given port is deferred until any
> > pl011_tx_softirq() work for that port is complete.
> >
> > Signed-off-by: Dave Martin <Dave.Martin@arm.com>
> > Tested-by: Robin Murphy <robin.murphy@arm.com>
> > Cc: stable <stable@vger.kernel.org> # 4.1
> > ---
> >
> > Another candidate for v4.1 if possible (sorry!) -- I thought this change
> > was already in, but it went astray when I was refactoring.
>
> Too late for 4.1, sorry. This doesn't apply to my tty-next branch,
No worries -- I was aware it was getting very late. The code this fixes
is obsoleted by -next, so it is relevant only for stable now.
> otherwise I would have queued it up there. Care to redo it and mark it
> for -stable, like I did above, and resend it?
Will do, thanks.
---Dave
WARNING: multiple messages have this Message-ID (diff)
From: Dave P Martin <Dave.Martin@arm.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Russell King" <linux@arm.linux.org.uk>,
"Jakub Kiciński" <moorray3@wp.pl>,
"Andre Przywara" <Andre.Przywara@arm.com>,
"Andrew Jackson" <Andrew.Jackson@arm.com>,
"Graeme Gregory" <gg@slimlogic.co.uk>,
"linux-serial@vger.kernel.org" <linux-serial@vger.kernel.org>,
"popcorn mix" <popcornmix@gmail.com>,
"Jorge Ramirez-Ortiz" <jorge.ramirez-ortiz@linaro.org>,
"Robin Murphy" <Robin.Murphy@arm.com>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH] serial/amba-pl011: Disable interrupts around TX softirq
Date: Mon, 15 Jun 2015 11:53:08 +0100 [thread overview]
Message-ID: <20150615105308.GA3649@e103592.cambridge.arm.com> (raw)
In-Reply-To: <20150613003945.GA10941@kroah.com>
On Sat, Jun 13, 2015 at 01:39:45AM +0100, Greg Kroah-Hartman wrote:
> On Fri, Jun 05, 2015 at 03:07:47PM +0100, Dave Martin wrote:
> > pl011_tx_softirq() currently uses spin_{,un}lock(), which are not
> > sufficient to inhibit pl011_int() from being triggered by a local
> > IRQ and trying to re-take the same lock. This can lead to
> > deadlocks.
> >
> > This patch uses the _irq() locking variants instead to ensure that
> > pl011_int() handling for a given port is deferred until any
> > pl011_tx_softirq() work for that port is complete.
> >
> > Signed-off-by: Dave Martin <Dave.Martin@arm.com>
> > Tested-by: Robin Murphy <robin.murphy@arm.com>
> > Cc: stable <stable@vger.kernel.org> # 4.1
> > ---
> >
> > Another candidate for v4.1 if possible (sorry!) -- I thought this change
> > was already in, but it went astray when I was refactoring.
>
> Too late for 4.1, sorry. This doesn't apply to my tty-next branch,
No worries -- I was aware it was getting very late. The code this fixes
is obsoleted by -next, so it is relevant only for stable now.
> otherwise I would have queued it up there. Care to redo it and mark it
> for -stable, like I did above, and resend it?
Will do, thanks.
---Dave
next prev parent reply other threads:[~2015-06-15 10:53 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-06-05 14:07 [PATCH] serial/amba-pl011: Disable interrupts around TX softirq Dave Martin
2015-06-05 14:07 ` Dave Martin
2015-06-05 18:03 ` Robin Murphy
2015-06-05 18:03 ` Robin Murphy
2015-06-08 10:34 ` Robin Murphy
2015-06-08 10:34 ` Robin Murphy
2015-06-08 11:34 ` Dave P Martin
2015-06-08 11:34 ` Dave P Martin
2015-06-13 0:39 ` Greg Kroah-Hartman
2015-06-13 0:39 ` Greg Kroah-Hartman
2015-06-15 10:53 ` Dave P Martin [this message]
2015-06-15 10:53 ` Dave P Martin
2015-06-15 11:09 ` Andre Przywara
2015-06-15 11:09 ` Andre Przywara
2015-06-15 14:03 ` Dave Martin
2015-06-15 14:03 ` Dave Martin
-- strict thread matches above, loose matches on Subject: below --
2015-06-18 13:54 Dave Martin
2015-06-18 13:54 ` Dave Martin
2015-06-20 9:09 ` Stefan Wahren
2015-06-20 9:09 ` Stefan Wahren
2015-06-20 9:09 ` Stefan Wahren
2015-06-23 11:13 ` Dave P Martin
2015-06-23 11:13 ` Dave P Martin
2015-07-09 10:57 Dave Martin
2015-07-09 10:57 ` Dave Martin
2015-07-23 22:05 ` Greg Kroah-Hartman
2015-07-23 22:05 ` Greg Kroah-Hartman
2015-07-24 9:56 ` Dave Martin
2015-07-24 9:56 ` Dave Martin
2015-07-24 15:15 ` Greg Kroah-Hartman
2015-07-24 15:15 ` Greg Kroah-Hartman
2015-07-24 16:46 ` Dave Martin
2015-07-24 16:46 ` Dave Martin
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