[PATCH] make level sensitive interrupt emulation default on SN2

[PATCH] make level sensitive interrupt emulation default on SN2

[Jeremy Higdon]

To simulate level-triggered interrupts on SN2, we need the
forced interrupt to be on by default.  Most PCI cards don't
need this, but the sata_vsc driver does.

thanks

jeremy

--- 2.6-devel/arch/ia64/sn/kernel/sn2/sn_proc_fs.c	2004-03-17 20:32:07.000000000 -0800
+++ linux-2.6.4/arch/ia64/sn/kernel/sn2/sn_proc_fs.c	2004-03-17 19:13:51.000000000 -0800
@@ -73,8 +73,13 @@
 	}
 }
 
-// Disable forced interrupts, but leave the code in, just in case.
-int sn_force_interrupt_flag = 0;
+/*
+ * Enable forced interrupt by default.
+ * When set, the sn interrupt handler writes the force interrupt register on
+ * the bridge chip.  The hardware will then send an interrupt message if the
+ * interrupt line is active.  This mimics a level sensitive interrupt.
+ */
+int sn_force_interrupt_flag = 1;
 
 static int
 sn_force_interrupt_read_proc(char *page, char **start, off_t off,

Re: [PATCH] make level sensitive interrupt emulation default on SN2

[Jesse Barnes]

Since our hw doesn't fully support level triggered interrupts, we need
this patch to force another interrupt if the line is still high after
a handler completes.  David, please apply.

Thanks,
Jesse

On Thursday 18 March 2004 5:46 pm, Jeremy Higdon wrote:
> To simulate level-triggered interrupts on SN2, we need the
> forced interrupt to be on by default.  Most PCI cards don't
> need this, but the sata_vsc driver does.