[tip:irq/urgent] genirq: Use irq type from irqdata instead of irqdesc

tip-bot for Thomas Gleixner
2016-11-08T14:22:29Z

Commit-ID: 7ee7e87dfb158e79019ea1d5ea1b0e6f2bc93ee4
Gitweb: http://git.kernel.org/tip/7ee7e87dfb158e79019ea1d5ea1b0e6f2bc93ee4
Author: Thomas Gleixner <tglx@linutronix.de>
AuthorDate: Mon, 7 Nov 2016 19:57:00 +0100
Committer: Thomas Gleixner <tglx@linutronix.de>
CommitDate: Tue, 8 Nov 2016 15:15:19 +0100

genirq: Use irq type from irqdata instead of irqdesc

The type flags in the irq descriptor are there for historical reasons and
only updated via irq_modify_status() or irq_set_type(). Both functions also
update the type flags in irqdata. __setup_irq() is the only left over user
of the type flags in the irq descriptor.

If __setup_irq() is called with empty irq type flags, then the type flags
are retrieved from irqdata. If an interrupt is shared, then the type flags
are compared with the type flags stored in the irq descriptor.

On x86 the ioapic does not have a irq_set_type() callback because the type
is defined in the BIOS tables and cannot be changed. The type is stored in
irqdata at setup time without updating the type data in the irq
descriptor. As a result the comparison described above fails.

There is no point in updating the irq descriptor flags because the only
relevant storage is irqdata. Use the type flags from irqdata for both
retrieval and comparison in __setup_irq() instead.

Aside of that the print out in case of non matching type flags has the old
and new type flags arguments flipped. Fix that as well.

For correctness sake the flags stored in the irq descriptor should be
removed, but this is beyond the scope of this bugfix and will be done in a
later patch.

Fixes: 4b357daed698 ("genirq: Look-up trigger type if not specified by caller")
Reported-and-tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Jon Hunter <jonathanh@nvidia.com>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1611072020360.3501@nanos
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

---
kernel/irq/manage.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 9c4d304..6b66959 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -1341,12 +1341,12 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)

} else if (new->flags & IRQF_TRIGGER_MASK) {
unsigned int nmsk = new->flags & IRQF_TRIGGER_MASK;
- unsigned int omsk = irq_settings_get_trigger_mask(desc);
+ unsigned int omsk = irqd_get_trigger_type(&desc->irq_data);

if (nmsk != omsk)
/* hope the handler works with current trigger mode */
pr_warn("irq %d uses trigger mode %u; requested %u\n",
- irq, nmsk, omsk);
+ irq, omsk, nmsk);
}

*old_ptr = new;