make level sensitive interrupt emulation default on SN2

PATCH In review Jeremy Higdon 2 participants 2 messages Mar 19, 2004

Share & tools

Jeremy Higdon

author

2004-03-19 01:46 UTC #0 lore raw

PATCH 1/1 make level sensitive interrupt emulation default on SN2

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

arch/ia64/sn/kernel/sn2/sn_proc_fs.c +7 -2

@@ -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,

Jesse Barnes

2004-03-19 01:54 UTC #1 lore raw

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

Quoted 3 lines · 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.