[PATCH] serial/amba-pl011: Disable interrupts around TX softirq

[Dave Martin]

On Thu, Jul 23, 2015 at 03:05:50PM -0700, Greg Kroah-Hartman wrote:
> 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 at arm.com>
> > Tested-by: Robin Murphy <robin.murphy at arm.com>
> > Tested-by: Stefan Wahren <stefan.wahren at i2se.com>
> > Cc: stable <stable at 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 :(

This is applicable to 4.1 stable only, since the code this patch fixes
was replaced in 4.2-rc1.

Apologies, I didn't make that clear in the text.

Cheers
---Dave