[PATCH RT 1/8] genirq: Unmask oneshot irqs when thread was not woken
From: Steven Rostedt <rostedt@goodmis.org>
Date: 2012-02-09 02:02:06
Also in:
lkml
Subsystem:
irq subsystem, the rest · Maintainers:
Thomas Gleixner, Linus Torvalds
From: Thomas Gleixner <redacted> When the primary handler of an interrupt which is marked IRQ_ONESHOT does not wake the thread (e.g. due to a spurious interrupt) then nothing ever unmasks the interrupt line again. Handle it gracefully. Cc: stable-rt@vger.kernel.org Reported-by: Lothar Wassmann <redacted> Signed-off-by: Thomas Gleixner <redacted> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> --- kernel/irq/chip.c | 25 +++++++++++++++++++++++-- 1 files changed, 23 insertions(+), 2 deletions(-)
diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index dc5114b..3322a34 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c@@ -312,6 +312,24 @@ out_unlock: } EXPORT_SYMBOL_GPL(handle_simple_irq); +/* + * Called unconditionally from handle_level_irq() and only for oneshot + * interrupts from handle_fasteoi_irq() + */ +static void cond_unmask_irq(struct irq_desc *desc) +{ + /* + * We need to unmask in the following cases: + * - Standard level irq (IRQF_ONESHOT is not set) + * - Oneshot irq which did not wake the thread (caused by a + * spurious interrupt or a primary handler handling it + * completely). + */ + if (!irqd_irq_disabled(&desc->irq_data) && + irqd_irq_masked(&desc->irq_data) && !desc->threads_oneshot) + unmask_irq(desc); +} + /** * handle_level_irq - Level type irq handler * @irq: the interrupt number
@@ -344,8 +362,8 @@ handle_level_irq(unsigned int irq, struct irq_desc *desc) handle_irq_event(desc); - if (!irqd_irq_disabled(&desc->irq_data) && !(desc->istate & IRQS_ONESHOT)) - unmask_irq(desc); + cond_unmask_irq(desc); + out_unlock: raw_spin_unlock(&desc->lock); }
@@ -399,6 +417,9 @@ handle_fasteoi_irq(unsigned int irq, struct irq_desc *desc) preflow_handler(desc); handle_irq_event(desc); + if (desc->istate & IRQS_ONESHOT) + cond_unmask_irq(desc); + out_eoi: desc->irq_data.chip->irq_eoi(&desc->irq_data); out_unlock:
--
1.7.8.3