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authorDavid S. Miller <davem@davemloft.net>2008-04-26 02:19:18 -0700
committerGreg Kroah-Hartman <gregkh@suse.de>2008-05-15 07:50:01 -0700
commita5f56179c861a23a2f08409711926ff812f30d38 (patch)
parent8f84dbc5ad1a37fe14a771f756beaa02b04401e6 (diff)
sparc64: Fix wedged irq regression.
[ Upstream commit: 92aa3573c9cd58fe0bcd1c52c9fd8f5708785917 ] Kernel bugzilla 10273 As reported by Jos van der Ende, ever since commit 5a606b72a4309a656cd1a19ad137dc5557c4b8ea ("[SPARC64]: Do not ACK an INO if it is disabled or inprogress.") sun4u interrupts can get stuck. What this changset did was add the following conditional to the various IRQ chip ->enable() handlers on sparc64: if (unlikely(desc->status & (IRQ_DISABLED|IRQ_INPROGRESS))) return; which is correct, however it means that special care is needed in the ->enable() method. Specifically we must put the interrupt into IDLE state during an enable, or else it might never be sent out again. Setting the INO interrupt state to IDLE resets the state machine, the interrupt input to the INO is retested by the hardware, and if an interrupt is being signalled by the device, the INO moves back into TRANSMIT state, and an interrupt vector is sent to the cpu. The two sun4v IRQ chip handlers were already doing this properly, only sun4u got it wrong. Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/sparc64/kernel/irq.c b/arch/sparc64/kernel/irq.c
index eb88bd6e674e..b441a26b73b0 100644
--- a/arch/sparc64/kernel/irq.c
+++ b/arch/sparc64/kernel/irq.c
@@ -1,6 +1,6 @@
/* irq.c: UltraSparc IRQ handling/init/registry.
- * Copyright (C) 1997, 2007 David S. Miller (davem@davemloft.net)
+ * Copyright (C) 1997, 2007, 2008 David S. Miller (davem@davemloft.net)
* Copyright (C) 1998 Eddie C. Dost (ecd@skynet.be)
* Copyright (C) 1998 Jakub Jelinek (jj@ultra.linux.cz)
@@ -308,6 +308,7 @@ static void sun4u_irq_enable(unsigned int virt_irq)
val |= tid | IMAP_VALID;
upa_writeq(val, imap);
+ upa_writeq(ICLR_IDLE, data->iclr);