x86, geode-mfgpt: check IRQ before using MFGPT as clocksource

Adds a simple IRQ autodetection to the AMD Geode MFGPT driver, and more
importantly, adds some checks, if IRQs can actually be received on the
chosen line.  This fixes cases where MFGPT is selected as clocksource
though not producing any ticks, so the kernel simply starves during
boot.

Signed-off-by: Jens Rottmann <JRottmann@LiPPERTEmbedded.de>
Cc: Andres Salomon <dilinger@debian.org>
Cc: linux-geode@bombadil.infradead.org
Cc: Jordan Crouse <jordan.crouse@amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 2 insertions, 1 deletions

diff --git a/include/asm-x86/geode.h b/include/asm-x86/geode.h
index bb06027fc83e..2c1cda0b8a86 100644
--- a/include/asm-x86/geode.h
+++ b/include/asm-x86/geode.h
@@ -50,6 +50,7 @@ extern int geode_get_dev_base(unsigned int dev);
 #define MSR_PIC_YSEL_HIGH       0x51400021
 #define MSR_PIC_ZSEL_LOW        0x51400022
 #define MSR_PIC_ZSEL_HIGH       0x51400023
+#define MSR_PIC_IRQM_LPC        0x51400025
 
 #define MSR_MFGPT_IRQ           0x51400028
 #define MSR_MFGPT_NR            0x51400029
@@ -237,7 +238,7 @@ static inline u16 geode_mfgpt_read(int timer, u16 reg)
 }
 
 extern int geode_mfgpt_toggle_event(int timer, int cmp, int event, int enable);
-extern int geode_mfgpt_set_irq(int timer, int cmp, int irq, int enable);
+extern int geode_mfgpt_set_irq(int timer, int cmp, int *irq, int enable);
 extern int geode_mfgpt_alloc_timer(int timer, int domain);
 
 #define geode_mfgpt_setup_irq(t, c, i) geode_mfgpt_set_irq((t), (c), (i), 1)