hpilo: reduce frequency of IO operations

Change hpilo open and close logic to spin for 10usec between checking device,
rather than every usec.

Because the loop is coded to take up to 10ms, it seemed prudent to
increase the interval between polling the device, to reduce the load on
the system and allow more other work to happen.

Signed-off-by: David Altobelli <david.altobelli@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/drivers/misc/hpilo.c b/drivers/misc/hpilo.c
index cf991850f01ba04b23ad40b1ded35747735b0bf4..880ccf39e23b1f70c83d26883c9a169ce76281f0 100644 (file)
--- a/drivers/misc/hpilo.c
+++ b/drivers/misc/hpilo.c
@@ -209,7 +209,7 @@ static void ilo_ccb_close(struct pci_dev *pdev, struct ccb_data *data)
        /* give iLO some time to process stop request */
        for (retries = MAX_WAIT; retries > 0; retries--) {
                doorbell_set(driver_ccb);
-               udelay(1);
+               udelay(WAIT_TIME);
                if (!(ioread32(&device_ccb->send_ctrl) & (1 << CTRL_BITPOS_A))
                    &&
                    !(ioread32(&device_ccb->recv_ctrl) & (1 << CTRL_BITPOS_A)))
@@ -312,7 +312,7 @@ static int ilo_ccb_open(struct ilo_hwinfo *hw, struct ccb_data *data, int slot)
        for (i = MAX_WAIT; i > 0; i--) {
                if (ilo_pkt_dequeue(hw, driver_ccb, SENDQ, &pkt_id, NULL, NULL))
                        break;
-               udelay(1);
+               udelay(WAIT_TIME);
        }
 
        if (i) {
@@ -759,7 +759,7 @@ static void __exit ilo_exit(void)
        class_destroy(ilo_class);
 }
 
-MODULE_VERSION("1.0");
+MODULE_VERSION("1.1");
 MODULE_ALIAS(ILO_NAME);
 MODULE_DESCRIPTION(ILO_NAME);
 MODULE_AUTHOR("David Altobelli <david.altobelli@hp.com>");

diff --git a/drivers/misc/hpilo.h b/drivers/misc/hpilo.h
index b64a20ef07e3cc6e7280386b5dc462233e1fd99a..03a14c82aad9bc9f0588cb3ee974ea5e2d8cd493 100644 (file)
--- a/drivers/misc/hpilo.h
+++ b/drivers/misc/hpilo.h
@@ -19,8 +19,12 @@
 #define MAX_ILO_DEV    1
 /* max number of files */
 #define MAX_OPEN       (MAX_CCB * MAX_ILO_DEV)
+/* total wait time in usec */
+#define MAX_WAIT_TIME  10000
+/* per spin wait time in usec */
+#define WAIT_TIME      10
 /* spin counter for open/close delay */
-#define MAX_WAIT       10000
+#define MAX_WAIT       (MAX_WAIT_TIME / WAIT_TIME)
 
 /*
  * Per device, used to track global memory allocations.