drm/bridge: it6505: Guard bridge power in IRQ handler

Add a pair of pm_runtime_get_if_in_use and pm_runtime_put_sync in the
interrupt handler to make sure the bridge won't be powered off during
the interrupt handlings. Also remove the irq_lock mutex because it's not
guarding anything now.

Fixes: ab28896f1a83 ("drm/bridge: it6505: Improve synchronization between extcon subsystem")
Signed-off-by: Pin-yen Lin <treapking@chromium.org>
Reviewed-by: Robert Foss <robert.foss@linaro.org>
Signed-off-by: Robert Foss <robert.foss@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20221109095227.3320919-1-treapking@chromium.org

diff --git a/drivers/gpu/drm/bridge/ite-it6505.c b/drivers/gpu/drm/bridge/ite-it6505.c
index fea2b42..5702569 100644 (file)
--- a/drivers/gpu/drm/bridge/ite-it6505.c
+++ b/drivers/gpu/drm/bridge/ite-it6505.c
@@ -412,7 +412,6 @@ struct it6505 {
         * Mutex protects extcon and interrupt functions from interfering
         * each other.
         */
-       struct mutex irq_lock;
        struct mutex extcon_lock;
        struct mutex mode_lock; /* used to bridge_detect */
        struct mutex aux_lock; /* used to aux data transfers */
@@ -2494,10 +2493,8 @@ static irqreturn_t it6505_int_threaded_handler(int unused, void *data)
        };
        int int_status[3], i;
 
-       mutex_lock(&it6505->irq_lock);
-
-       if (it6505->enable_drv_hold || !it6505->powered)
-               goto unlock;
+       if (it6505->enable_drv_hold || pm_runtime_get_if_in_use(dev) <= 0)
+               return IRQ_HANDLED;
 
        int_status[0] = it6505_read(it6505, INT_STATUS_01);
        int_status[1] = it6505_read(it6505, INT_STATUS_02);
@@ -2515,16 +2512,14 @@ static irqreturn_t it6505_int_threaded_handler(int unused, void *data)
        if (it6505_test_bit(irq_vec[0].bit, (unsigned int *)int_status))
                irq_vec[0].handler(it6505);
 
-       if (!it6505->hpd_state)
-               goto unlock;
-
-       for (i = 1; i < ARRAY_SIZE(irq_vec); i++) {
-               if (it6505_test_bit(irq_vec[i].bit, (unsigned int *)int_status))
-                       irq_vec[i].handler(it6505);
+       if (it6505->hpd_state) {
+               for (i = 1; i < ARRAY_SIZE(irq_vec); i++) {
+                       if (it6505_test_bit(irq_vec[i].bit, (unsigned int *)int_status))
+                               irq_vec[i].handler(it6505);
+               }
        }
 
-unlock:
-       mutex_unlock(&it6505->irq_lock);
+       pm_runtime_put_sync(dev);
 
        return IRQ_HANDLED;
 }
@@ -3276,7 +3271,6 @@ static int it6505_i2c_probe(struct i2c_client *client)
        if (!it6505)
                return -ENOMEM;
 
-       mutex_init(&it6505->irq_lock);
        mutex_init(&it6505->extcon_lock);
        mutex_init(&it6505->mode_lock);
        mutex_init(&it6505->aux_lock);