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

[Dave P Martin]

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 at arm.com>
> > Tested-by: Robin Murphy <robin.murphy at arm.com>
> > Cc: stable <stable at 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