• Gregory CLEMENT's avatar
    arm: mvebu: Fix the irq map function in SMP mode · 600468d0
    Gregory CLEMENT authored
    This patch fix the regression introduced by the commit 3202bf01
    "arm: mvebu: Improve the SMP support of the interrupt controller":
    GPIO IRQ were no longer delivered to the CPUs.
    
    To be delivered to a CPU an interrupt must be enabled at CPU level and
    at interrupt source level. Before the offending patch, all the
    interrupts were enabled at source level during map() function. Mask()
    and unmask() was done by handling the per-CPU part. It was fine when
    running in UP with only one CPU.
    
    The offending patch added support for SMP, in this case mask() and
    unmask() was done by handling the interrupt source level part. The
    per-CPU level part was handled by the affinity API to select the CPU
    which will receive the interrupt. (Due to some hardware limitation
    only one CPU at a time can received a given interrupt).
    
    For "normal" interrupt __setup_irq() was called when an irq was
    registered. irq_set_affinity() is called from this function, which
    enabled the interrupt on one of the CPUs. Whereas for GPIO IRQ which
    were chained interrupts, the irq_set_affinity() was never called and
    none of the CPUs was selected to receive the interrupt.
    
    With this patch all the interrupt are enable on the current CPU during
    map() function. Enabling the interrupts on a CPU doesn't depend
    anymore on irq_set_affinity() and then the chained irq are not anymore
    a special case. However the CPU which will receive the irq can still
    be modify later using irq_set_affinity().
    
    Tested with Mirabox (A370) and Openblocks AX3 (AXP), rootfs mounted
    over NFS, compiled with CONFIG_SMP=y/N.
    Signed-off-by: default avatarGregory CLEMENT <gregory.clement@free-electrons.com>
    Reported-by: default avatarRyan Press <ryan@presslab.us>
    Investigated-by: default avatarEzequiel Garcia <ezequiel.garcia@free-electrons.com>
    Tested-by: default avatarEzequiel Garcia <ezequiel.garcia@free-electrons.com>
    Tested-by: default avatarRyan Press <ryan@presslab.us>
    Signed-off-by: default avatarJason Cooper <jason@lakedaemon.net>
    600468d0
irq-armada-370-xp.c 7.25 KB