Commits
Evgeniy Dushistov committed 9ece8839b12
ARM: orion: Fix for certain sequence of request_irq can cause irq storm The problem is that hardware handled by arm/plat-orion/gpio.c, require ack for edge irq, and no ack for level irq. The code handle this issue, by two "struct irq_chip_type" per one "struct irq_chip_generic". For one "struct irq_chip_generic" irq_ack pointer is setted, for another it is NULL. But we have only one mask_cache per two "struct irq_chip_type". So if we 1)unmask interrupt A for "edge type" trigger, 2)unmask interrupt B for "level type" trigger, 3)unmask interrupt C for "edge type", we, because of usage of generic irq_gc_mask_clr_bit/irq_gc_mask_set_bit, have hardware configured to trigger interrupt B on "edge type", because of shared mask_cache. But kernel think that B is "level type", so when interrupt B occur via "edge" reason, we don't ack it, and B triggered again and again. Signed-off-by: Evgeniy A. Dushistov <dushistov@mail.ru> Link: https://lkml.kernel.org/r/20140726155659.GA22977@fifteen Signed-off-by: Jason Cooper <jason@lakedaemon.net>