genirq: Add support for nested shared IRQs
PATCH v2 1/1 genirq: Add support for nested shared IRQs
I am working on a system which has an audio CODEC and two speaker amps, each of the speaker amps have an open-drain IRQ line which are connected together and attached to a pin on the audio CODEC, which is capable of functioning as an IRQ chip. The audio CODEC then in turn has its own IRQ line which heads back to the host processor.
This setup necessitates having a shared nested IRQ on the audio CODEC. Currently however the kernel does not appear to support shared nested IRQs.
Fortunately support is fairly easy to add, only required the modification of handle_nested_irq to call all the IRQ handlers, rather than just the first one associated with the IRQ.
---
Changes since v1:
- Improve commit messages
- Use for_each_action_of_desc
- Correct handling of note_interrupt
Thanks,
Charles
kernel/irq/chip.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
kernel/irq/chip.c +4 -1
@@ -348,7 +348,10 @@ void handle_nested_irq(unsigned int irq)irqd_set (&desc->irq_data,IRQD_IRQ_INPROGRESS );raw_spin_unlock_irq (&desc->lock); - action_ret = action->thread_fn (action->irq, action->dev_id); + action_ret =IRQ_NONE ; +for_each_action_of_desc (desc, action) + action_ret |= action->thread_fn (action->irq, action->dev_id); +if (!noirqdebug)note_interrupt (desc, action_ret);
Signature · 1 line
2.1.4
tip-bot for Charles Keepax
merge botgenirq: Add support for nested shared IRQs
Commit-ID: 45e5202213ae6541f7916bb3c64fbcd3019ec473 Gitweb: http://git.kernel.org/tip/45e5202213ae6541f7916bb3c64fbcd3019ec473 Author: Charles Keepax <[email protected]> AuthorDate: Tue, 7 Mar 2017 16:28:18 +0000 Committer: Thomas Gleixner <[email protected]> CommitDate: Sat, 11 Mar 2017 12:57:03 +0100
genirq: Add support for nested shared IRQs
On a specific audio system an interrupt input of an audio CODEC is used as a shared interrupt. That interrupt input is handled by a CODEC specific irq chip driver and triggers a CPU interrupt via the CODEC irq output line.
The CODEC interrupt handler demultiplexes the CODEC interrupt inputs and the interrupt handlers for these demultiplexed inputs run nested in the context of the CODEC interrupt handler.
The demultiplexed interrupts use handle_nested_irq() as their interrupt handler, which unfortunately has no support for shared interrupts. So the above hardware cannot be supported.
Add shared interrupt support to handle_nested_irq() by iterating over the interrupt action chain.
[ tglx: Massaged changelog ]
--- kernel/irq/chip.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
kernel/irq/chip.c +4 -1
@@ -348,7 +348,10 @@ void handle_nested_irq(unsigned int irq)irqd_set (&desc->irq_data,IRQD_IRQ_INPROGRESS );raw_spin_unlock_irq (&desc->lock); - action_ret = action->thread_fn (action->irq, action->dev_id); + action_ret =IRQ_NONE ; +for_each_action_of_desc (desc, action) + action_ret |= action->thread_fn (action->irq, action->dev_id); +if (!noirqdebug)note_interrupt (desc, action_ret);