Input: ads7846 - fix unsafe disable_irq

The use of disable_irq inside the handler for the interrupt being
disabled has always been dangerous.  disable_irq should wait for that
handler to complete before returning -> deadlock.

For some reason this wasn't actually the case until 3aa551c9b was merged
but since this time, the ads7846 driver has deadlocked the system on
first interrupt.

Convert the driver to use the handler-safe _nosync variant.

Signed-off-by: Ben Nizette <bn@niasdigital.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

diff --git a/drivers/input/touchscreen/ads7846.c b/drivers/input/touchscreen/ads7846.c
index cf7e69766b2b778ea77f8f797a7b56ba60a597ac..8b6e30ac2919a324242f43364e795e478ec4da9e 100644 (file)
--- a/drivers/input/touchscreen/ads7846.c
+++ b/drivers/input/touchscreen/ads7846.c
@@ -754,7 +754,7 @@ static irqreturn_t ads7846_irq(int irq, void *handle)
                         * that here.  (The "generic irq" framework may help...)
                         */
                        ts->irq_disabled = 1;
-                       disable_irq(ts->spi->irq);
+                       disable_irq_nosync(ts->spi->irq);
                        ts->pending = 1;
                        hrtimer_start(&ts->timer, ktime_set(0, TS_POLL_DELAY),
                                        HRTIMER_MODE_REL);