From 6e4741e73b266f02e4b6d166ac278afd86c4dceb Mon Sep 17 00:00:00 2001 From: Andreas Larsson Date: Sun, 21 Apr 2013 21:23:06 +0000 Subject: [PATCH] sparc32, leon: Do not overwrite previously set irq flow handlers This is needed because when scan_of_devices finds the GAISLER_GPTIMER core that corresponds to the SMP "ticker" timer, the previously set proper irq flow handler gets overwritten with an incorrect one. This leads to very flaky timer interrupt handling on some hardware. Proper updates to handlers can still be done using leon_update_virq_handling. Signed-off-by: Andreas Larsson Signed-off-by: David S. Miller --- arch/sparc/kernel/leon_kernel.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/arch/sparc/kernel/leon_kernel.c b/arch/sparc/kernel/leon_kernel.c index 87f60ee..7c0231d 100644 --- a/arch/sparc/kernel/leon_kernel.c +++ b/arch/sparc/kernel/leon_kernel.c @@ -213,6 +213,7 @@ unsigned int leon_build_device_irq(unsigned int real_irq, { unsigned int irq; unsigned long mask; + struct irq_desc *desc; irq = 0; mask = leon_get_irqmask(real_irq); @@ -226,9 +227,12 @@ unsigned int leon_build_device_irq(unsigned int real_irq, if (do_ack) mask |= LEON_DO_ACK_HW; - irq_set_chip_and_handler_name(irq, &leon_irq, - flow_handler, name); - irq_set_chip_data(irq, (void *)mask); + desc = irq_to_desc(irq); + if (!desc || !desc->handle_irq || desc->handle_irq == handle_bad_irq) { + irq_set_chip_and_handler_name(irq, &leon_irq, + flow_handler, name); + irq_set_chip_data(irq, (void *)mask); + } out: return irq; -- 2.7.4