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authorBarry Song <song.bao.hua@hisilicon.com>2021-03-03 11:49:15 +1300
committerIngo Molnar <mingo@kernel.org>2021-03-06 12:48:00 +0100
commitcbe16f35bee6880becca6f20d2ebf6b457148552 (patch)
tree4c82c004e0be2e9100af1407c11b5f35028a0d48 /include/linux/interrupt.h
parenta38fd8748464831584a19438cbb3082b5a2dab15 (diff)
genirq: Add IRQF_NO_AUTOEN for request_irq/nmi()
Many drivers don't want interrupts enabled automatically via request_irq(). So they are handling this issue by either way of the below two: (1) irq_set_status_flags(irq, IRQ_NOAUTOEN); request_irq(dev, irq...); (2) request_irq(dev, irq...); disable_irq(irq); The code in the second way is silly and unsafe. In the small time gap between request_irq() and disable_irq(), interrupts can still come. The code in the first way is safe though it's subobtimal. Add a new IRQF_NO_AUTOEN flag which can be handed in by drivers to request_irq() and request_nmi(). It prevents the automatic enabling of the requested interrupt/nmi in the same safe way as #1 above. With that the various usage sites of #1 and #2 above can be simplified and corrected. Signed-off-by: Barry Song <song.bao.hua@hisilicon.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: dmitry.torokhov@gmail.com Link: https://lore.kernel.org/r/20210302224916.13980-2-song.bao.hua@hisilicon.com
Diffstat (limited to 'include/linux/interrupt.h')
-rw-r--r--include/linux/interrupt.h4
1 files changed, 4 insertions, 0 deletions
diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
index 967e25767153..76f1161a441a 100644
--- a/include/linux/interrupt.h
+++ b/include/linux/interrupt.h
@@ -61,6 +61,9 @@
* interrupt handler after suspending interrupts. For system
* wakeup devices users need to implement wakeup detection in
* their interrupt handlers.
+ * IRQF_NO_AUTOEN - Don't enable IRQ or NMI automatically when users request it.
+ * Users will enable it explicitly by enable_irq() or enable_nmi()
+ * later.
*/
#define IRQF_SHARED 0x00000080
#define IRQF_PROBE_SHARED 0x00000100
@@ -74,6 +77,7 @@
#define IRQF_NO_THREAD 0x00010000
#define IRQF_EARLY_RESUME 0x00020000
#define IRQF_COND_SUSPEND 0x00040000
+#define IRQF_NO_AUTOEN 0x00080000
#define IRQF_TIMER (__IRQF_TIMER | IRQF_NO_SUSPEND | IRQF_NO_THREAD)