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From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Dave Martin <Dave.Martin@arm.com>
Cc: linux-serial@vger.kernel.org,
	"Russell King" <linux@arm.linux.org.uk>,
	"Robin Murphy" <Robin.Murphy@arm.com>,
	linux-arm-kernel@lists.infradead.org,
	"Jakub Kiciński" <moorray3@wp.pl>,
	"Andrew Jackson" <Andrew.Jackson@arm.com>,
	"Graeme Gregory" <gg@slimlogic.co.uk>,
	"Andre Przywara" <Andre.Przywara@arm.com>,
	"Jorge Ramirez-Ortiz" <jorge.ramirez-ortiz@linaro.org>,
	"popcorn mix" <popcornmix@gmail.com>,
	stable@vger.kernel.org
Subject: Re: [PATCH] serial/amba-pl011: Disable interrupts around TX softirq
Date: Thu, 23 Jul 2015 15:05:50 -0700	[thread overview]
Message-ID: <20150723220550.GA15032@kroah.com> (raw)
In-Reply-To: <1436439433-10258-1-git-send-email-Dave.Martin@arm.com>

On Thu, Jul 09, 2015 at 11:57:12AM +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.
> 
> Fixes: 734745caeb9f serial/amba-pl011: Activate TX IRQ passively
> Signed-off-by: Dave Martin <Dave.Martin@arm.com>
> Tested-by: Robin Murphy <robin.murphy@arm.com>
> Tested-by: Stefan Wahren <stefan.wahren@i2se.com>
> Cc: stable <stable@vger.kernel.org> # 4.1
> ---
>  drivers/tty/serial/amba-pl011.c |    4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)

This doesn't apply at all to 4.2-rc3, so I can't apply it :(


WARNING: multiple messages have this Message-ID (diff)
From: gregkh@linuxfoundation.org (Greg Kroah-Hartman)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] serial/amba-pl011: Disable interrupts around TX softirq
Date: Thu, 23 Jul 2015 15:05:50 -0700	[thread overview]
Message-ID: <20150723220550.GA15032@kroah.com> (raw)
In-Reply-To: <1436439433-10258-1-git-send-email-Dave.Martin@arm.com>

On Thu, Jul 09, 2015 at 11:57:12AM +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.
> 
> Fixes: 734745caeb9f serial/amba-pl011: Activate TX IRQ passively
> Signed-off-by: Dave Martin <Dave.Martin@arm.com>
> Tested-by: Robin Murphy <robin.murphy@arm.com>
> Tested-by: Stefan Wahren <stefan.wahren@i2se.com>
> Cc: stable <stable@vger.kernel.org> # 4.1
> ---
>  drivers/tty/serial/amba-pl011.c |    4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)

This doesn't apply at all to 4.2-rc3, so I can't apply it :(

  reply	other threads:[~2015-07-23 22:05 UTC|newest]

Thread overview: 33+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-07-09 10:57 [PATCH] serial/amba-pl011: Disable interrupts around TX softirq Dave Martin
2015-07-09 10:57 ` Dave Martin
2015-07-23 22:05 ` Greg Kroah-Hartman [this message]
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
  -- 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
2015-06-05 14:07 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
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

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