Use usleep_range instead of msleep when waiting for command
completion. Most SMBus commands complete in less than 2 jiffies so
this brings a pleasant performance boost.
Strongly inspired from a similar change by Olivier Sobrie to the
i2c-isch driver.
Signed-off-by: Jean Delvare <khali@xxxxxxxxxxxx>
Cc: Olivier Sobrie <olivier@xxxxxxxxx>
---
drivers/i2c/busses/i2c-i801.c | 24 ++++++++++++------------
1 file changed, 12 insertions(+), 12 deletions(-)
--- linux-3.3-rc1.orig/drivers/i2c/busses/i2c-i801.c 2012-01-24 16:55:37.734394612 +0100
+++ linux-3.3-rc1/drivers/i2c/busses/i2c-i801.c 2012-01-24 17:51:00.921443870 +0100
@@ -2,7 +2,7 @@
Copyright (c) 1998 - 2002 Frodo Looijaard <frodol@xxxxxx>,
Philip Edelbrock <phil@xxxxxxxxxxxxx>, and Mark D. Studebaker
<mdsxyz123@xxxxxxxxx>
- Copyright (C) 2007, 2008 Jean Delvare <khali@xxxxxxxxxxxx>
+ Copyright (C) 2007 - 2012 Jean Delvare <khali@xxxxxxxxxxxx>
Copyright (C) 2010 Intel Corporation,
David Woodhouse <dwmw2@xxxxxxxxxxxxx>
@@ -106,7 +106,7 @@
#define SMBHSTCNT_KILL 2
/* Other settings */
-#define MAX_TIMEOUT 100
+#define MAX_RETRIES 400
#define ENABLE_INT9 0 /* set to 0x01 to enable - untested */
/* I801 command constants */
@@ -217,7 +217,7 @@ static int i801_check_post(struct i801_p
dev_dbg(&priv->pci_dev->dev, "Terminating the current operation\n");
outb_p(inb_p(SMBHSTCNT(priv)) | SMBHSTCNT_KILL,
SMBHSTCNT(priv));
- msleep(1);
+ usleep_range(1000, 2000);
outb_p(inb_p(SMBHSTCNT(priv)) & (~SMBHSTCNT_KILL),
SMBHSTCNT(priv));
@@ -274,11 +274,11 @@ static int i801_transaction(struct i801_
/* We will always wait for a fraction of a second! */
do {
- msleep(1);
+ usleep_range(250, 500);
status = inb_p(SMBHSTSTS(priv));
- } while ((status & SMBHSTSTS_HOST_BUSY) && (timeout++ < MAX_TIMEOUT));
+ } while ((status & SMBHSTSTS_HOST_BUSY) && (timeout++ < MAX_RETRIES));
- result = i801_check_post(priv, status, timeout > MAX_TIMEOUT);
+ result = i801_check_post(priv, status, timeout > MAX_RETRIES);
if (result < 0)
return result;
@@ -293,12 +293,12 @@ static void i801_wait_hwpec(struct i801_
int status;
do {
- msleep(1);
+ usleep_range(250, 500);
status = inb_p(SMBHSTSTS(priv));
} while ((!(status & SMBHSTSTS_INTR))
- && (timeout++ < MAX_TIMEOUT));
+ && (timeout++ < MAX_RETRIES));
- if (timeout > MAX_TIMEOUT)
+ if (timeout > MAX_RETRIES)
dev_dbg(&priv->pci_dev->dev, "PEC Timeout!\n");
outb_p(status, SMBHSTSTS(priv));
@@ -382,12 +382,12 @@ static int i801_block_transaction_byte_b
/* We will always wait for a fraction of a second! */
timeout = 0;
do {
- msleep(1);
+ usleep_range(250, 500);
status = inb_p(SMBHSTSTS(priv));
} while ((!(status & SMBHSTSTS_BYTE_DONE))
- && (timeout++ < MAX_TIMEOUT));
+ && (timeout++ < MAX_RETRIES));
- result = i801_check_post(priv, status, timeout > MAX_TIMEOUT);
+ result = i801_check_post(priv, status, timeout > MAX_RETRIES);
if (result < 0)
return result;
--
Jean Delvare
--
To unsubscribe from this list: send the line "unsubscribe linux-i2c" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
