@@ -1168,6 +1168,14 @@ static int
new->flags &= ~IRQF_ONESHOT;
mutex_lock(&desc->request_mutex);
+ if (!desc->action) {
+ ret = irq_request_resources(desc);
+ if (ret) {
+ pr_err("Failed to request resources for %s (irq %d) on irqchip %s\n",
+ new->name, irq, desc->irq_data.chip->name);
+ goto out_mutex;
+ }
+ }
chip_bus_lock(desc);
@@ -1271,13 +1279,6 @@ static int
}
if (!shared) {
- ret = irq_request_resources(desc);
- if (ret) {
- pr_err("Failed to request resources for %s (irq %d) on irqchip %s\n",
- new->name, irq, desc->irq_data.chip->name);
- goto out_unlock;
- }
-
init_waitqueue_head(&desc->wait_for_threads);
/* Setup the type (level, edge polarity) if configured: */
@@ -1386,6 +1387,10 @@ static int
chip_bus_sync_unlock(desc);
+ if (!desc->action)
+ irq_release_resources(desc);
+
+out_mutex:
mutex_unlock(&desc->request_mutex);
out_thread:
@@ -1484,7 +1489,6 @@ static struct irqaction *__free_irq(unsi
if (!desc->action) {
irq_settings_clr_disable_unlazy(desc);
irq_shutdown(desc);
- irq_release_resources(desc);
irq_remove_timings(desc);
}
@@ -1527,6 +1531,9 @@ static struct irqaction *__free_irq(unsi
}
}
+ if (!desc->action)
+ irq_release_resources(desc);
+
mutex_unlock(&desc->request_mutex);
irq_chip_pm_put(&desc->irq_data);
Aside of being conceptually wrong, there is also an actual (hard to trigger and mostly theoretical) problem. CPU0 CPU1 free_irq(X) interrupt X spin_lock(desc->lock) wake irq thread() spin_unlock(desc->lock) spin_lock(desc->lock) remove action() shutdown_irq() release_resources() thread_handler() spin_unlock(desc->lock) access released resources. synchronize_irq() Move the release resources invocation after synchronize_irq() so it's guaranteed that the threaded handler has finished. Move the resource request call out of the desc->lock held region as well, so the invocation context is the same for both request and release. This solves the problems with those functions on RT as well. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> --- kernel/irq/manage.c | 23 +++++++++++++++-------- 1 file changed, 15 insertions(+), 8 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe linux-gpio" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html