Commit-ID: 56af0416b00f6edc7845a7b3f2ef179e385c8e15 Gitweb: http://git.kernel.org/tip/56af0416b00f6edc7845a7b3f2ef179e385c8e15 Author: Hans de Goede <hdego...@redhat.com> AuthorDate: Thu, 13 Mar 2014 19:03:52 +0100 Committer: Thomas Gleixner <t...@linutronix.de> CommitDate: Fri, 14 Mar 2014 13:43:33 +0100
irqchip: sun4i: Fix irq 0 not working SUN4I_IRQ_VECTOR_REG containing 0 can mean one of 3 things: 1) no more irqs pending 2) irq 0 pending 3) spurious irq So if we immediately get a reading of 0, check the irq-pending reg to differentiate between 2 and 3. We only do this once to avoid the extra check in the common case of 1) hapening after having read the vector-reg once. Signed-off-by: Hans de Goede <hdego...@redhat.com> Acked-by: Maxime Ripard <maxime.rip...@free-electrons.com> Cc: linux-arm-ker...@lists.infradead.org Cc: linux-su...@googlegroups.com Link: http://lkml.kernel.org/r/1394733834-26839-3-git-send-email-hdego...@redhat.com Signed-off-by: Thomas Gleixner <t...@linutronix.de> --- drivers/irqchip/irq-sun4i.c | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-) diff --git a/drivers/irqchip/irq-sun4i.c b/drivers/irqchip/irq-sun4i.c index 1599955..7ae85ec 100644 --- a/drivers/irqchip/irq-sun4i.c +++ b/drivers/irqchip/irq-sun4i.c @@ -140,10 +140,24 @@ static void __exception_irq_entry sun4i_handle_irq(struct pt_regs *regs) { u32 irq, hwirq; + /* + * hwirq == 0 can mean one of 3 things: + * 1) no more irqs pending + * 2) irq 0 pending + * 3) spurious irq + * So if we immediately get a reading of 0, check the irq-pending reg + * to differentiate between 2 and 3. We only do this once to avoid + * the extra check in the common case of 1 hapening after having + * read the vector-reg once. + */ hwirq = readl(sun4i_irq_base + SUN4I_IRQ_VECTOR_REG) >> 2; - while (hwirq != 0) { + if (hwirq == 0 && + !(readl(sun4i_irq_base + SUN4I_IRQ_PENDING_REG(0)) & BIT(0))) + return; + + do { irq = irq_find_mapping(sun4i_irq_domain, hwirq); handle_IRQ(irq, regs); hwirq = readl(sun4i_irq_base + SUN4I_IRQ_VECTOR_REG) >> 2; - } + } while (hwirq != 0); } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
