pciehp: fix wait command completion
This patch fixes this problem that pciehp driver will sleep
unnecessarily long when waiting for command completion. With this
patch, modprobe pciehp driver becomes very faster as follows for
instance.
o Without this patch
# time /sbin/modprobe pciehp
real 0m4.976s
user 0m0.000s
sys 0m0.004s
o With this patch
# time /sbin/modprobe pciehp
real 0m0.640s
user 0m0.000s
sys 0m0.004s
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/pci/hotplug/pciehp.h b/drivers/pci/hotplug/pciehp.h
index 17167d5..927dba9 100644
--- a/drivers/pci/hotplug/pciehp.h
+++ b/drivers/pci/hotplug/pciehp.h
@@ -100,6 +100,7 @@
u16 vendor_id;
u8 cap_base;
struct timer_list poll_timer;
+ volatile int cmd_busy;
};
#define INT_BUTTON_IGNORE 0
diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c
index 9fbd9b9..eb1862b 100644
--- a/drivers/pci/hotplug/pciehp_hpc.c
+++ b/drivers/pci/hotplug/pciehp_hpc.c
@@ -251,20 +251,21 @@
static inline int pcie_wait_cmd(struct controller *ctrl)
{
- DECLARE_WAITQUEUE(wait, current);
+ int retval = 0;
+ unsigned int msecs = pciehp_poll_mode ? 2500 : 1000;
+ unsigned long timeout = msecs_to_jiffies(msecs);
+ int rc;
- add_wait_queue(&ctrl->queue, &wait);
- if (!pciehp_poll_mode)
- /* Sleep for up to 1 second */
- msleep_interruptible(1000);
- else
- msleep_interruptible(2500);
+ rc = wait_event_interruptible_timeout(ctrl->queue,
+ !ctrl->cmd_busy, timeout);
+ if (!rc)
+ dbg("Command not completed in 1000 msec\n");
+ else if (rc < 0) {
+ retval = -EINTR;
+ info("Command was interrupted by a signal\n");
+ }
- remove_wait_queue(&ctrl->queue, &wait);
- if (signal_pending(current))
- return -EINTR;
-
- return 0;
+ return retval;
}
static int pcie_write_cmd(struct slot *slot, u16 cmd)
@@ -291,6 +292,7 @@
__FUNCTION__);
}
+ ctrl->cmd_busy = 1;
retval = pciehp_writew(ctrl, SLOTCTRL, (cmd | CMD_CMPL_INTR_ENABLE));
if (retval) {
err("%s: Cannot write to SLOTCTRL register\n", __FUNCTION__);
@@ -773,6 +775,7 @@
/*
* Command Complete Interrupt Pending
*/
+ ctrl->cmd_busy = 0;
wake_up_interruptible(&ctrl->queue);
}