[PATCH] shpchp: fix improper wait for command completion
Current SHPCHP driver uses msleep_interruptible() function to wait for
a command completion event. But I think this would cause an unnecessary
long wait until timeout, if command completion interrupt came before
task state was changed to TASK_INTERRUPTIBLE. This patch fixes this
issue. With this patch, command completion becomes faster as follows:
o Without this patch
# time echo 1 > power
real 0m4.708s
user 0m0.000s
sys 0m0.524s
o With this patch
# time echo 1 > power
real 0m2.221s
user 0m0.000s
sys 0m0.532s
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/pci/hotplug/shpchp.h b/drivers/pci/hotplug/shpchp.h
index 55b0cd1..ce0e9b6 100644
--- a/drivers/pci/hotplug/shpchp.h
+++ b/drivers/pci/hotplug/shpchp.h
@@ -101,6 +101,7 @@
u32 cap_offset;
unsigned long mmio_base;
unsigned long mmio_size;
+ volatile int cmd_busy;
};
struct hotplug_params {