Messages in this thread | | | From | Thomas Petazzoni <> | Subject | [PATCH 0/5] Fix regression introduced by set_irq_flags() removal | Date | Tue, 20 Oct 2015 15:23:50 +0200 |
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Thomas, Jason, Marc, Rob,
In commit d17cab4451df ("irqchip: Kill off set_irq_flags usage"), Rob Herring modified the irqchip drivers to not use the ARM-specific set_irq_flags() and instead rely on various functions provided by the core irq subsystem.
While his commit was supposed to have no functional effect, it in fact does have one effect: the IRQ_NOAUTOEN flag used to be *cleared* for all interrupts and it is now *set* by default.
Thanks to this flag being *cleared* by default, the irq-armada-370-xp was able to properly re-enable per-CPU interrupts at resume time. Now that this flag is *set*, the irqd_irq_disabled() function no longer indicates that such per-CPU interrupts are enabled (and in fact a CPU-global flag to tell whether a per-CPU is enabled or not is silly). Due to this, our local timer per-CPU interrupt is no longer re-enabled at resume time on Armada XP, on the boot CPU, which causes a hang at resume time.
This is a regression between 4.2 (where suspend/resume works fine) and 4.3-rc (where suspend/resume is broken). Reverting d17cab4451df1 on top of 4.3-rc makes the problem go away (of course you also need to revert eb811129ed9ea so that set_irq_flags is re-introduced).
The minimal fix would be to clear the IRQ_NOAUTOEN flag so that we get back to the original situation. However, this does not really seem like the right fix.
Instead, this patch series proposes to add an is_enabled_percpu_irq() function to the core irq subsystem, which is then used by the irq-armada-370-xp to find out if such or such per-CPU interrupt should be re-enabled at resume time on the boot CPU.
The organization of the patch series is as follows:
- PATCH 1 introduces the is_enabled_percpu_irq() function.
- PATCH 2 does a minor refactoring of armada_xp_mpic_secondary_init() to prepare the following patch.
- PATCH 3 changes the irq-armada-370-xp driver to use the is_enabled_percpu_irq() to re-enable the per-CPU interrupts on the boot CPU at resume time, and also modifies the secondary CPU notifier to re-enable per-CPU interrupts if needed.
- PATCH 4 and 5 are further cleanups/improvements to the irq-armada-370-xp, which are not needed to fix the problem.
Since this is fixing a regression introduced between 4.2 and 4.3-rc, it would be great if patches 1 to 3 could be merged in 4.3. The last two patches are only cosmetic, so merging them for 4.4 is of course the way to go.
Thanks,
Thomas
Thomas Petazzoni (5): kernel: irq: implement is_enabled_percpu_irq() irqchip: armada-370-xp: prepare additions to armada_xp_mpic_secondary_init() irqchip: armada-370-xp: re-enable per-CPU interrupts at resume time irqchip: armada-370-xp: re-order register definitions irqchip: armada-370-xp: document the overall driver logic
drivers/irqchip/irq-armada-370-xp.c | 151 +++++++++++++++++++++++++++++++----- include/linux/interrupt.h | 1 + kernel/irq/chip.c | 5 ++ kernel/irq/internals.h | 1 + kernel/irq/manage.c | 19 +++++ 5 files changed, 158 insertions(+), 19 deletions(-)
-- 2.6.2
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