On Fri, Jul 24, 2015 at 10:56:06AM +0100, Dave Martin wrote:
> 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@xxxxxxx>
> > > Tested-by: Robin Murphy <robin.murphy@xxxxxxx>
> > > Tested-by: Stefan Wahren <stefan.wahren@xxxxxxxx>
> > > Cc: stable <stable@xxxxxxxxxxxxxxx> # 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.
I can't do anything with a 4.1-only patch, please read
Documentation/stable_kernel_rules.txt for how to get a patch into the
stable kernel releases.
thanks,
greg k-h
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