diff options
| author | Jean Delvare <khali@linux-fr.org> | 2012-03-26 21:47:19 +0200 |
|---|---|---|
| committer | Jean Delvare <khali@endymion.delvare> | 2012-03-26 21:47:19 +0200 |
| commit | 84c1af4c21d645a02a4780cdf61c7551d8e7bb56 (patch) | |
| tree | 47ad0ea490045e73c6f4d757123ac4c95ea0a676 /drivers/i2c/busses/i2c-i801.c | |
| parent | 062737fb6d90c632439b1f77ad6a4965cfc84a20 (diff) | |
| download | lwn-84c1af4c21d645a02a4780cdf61c7551d8e7bb56.tar.gz lwn-84c1af4c21d645a02a4780cdf61c7551d8e7bb56.zip | |
i2c-i801: Use usleep_range to wait for command completion
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@linux-fr.org>
Cc: Olivier Sobrie <olivier@sobrie.be>
Diffstat (limited to 'drivers/i2c/busses/i2c-i801.c')
| -rw-r--r-- | drivers/i2c/busses/i2c-i801.c | 24 |
1 files changed, 12 insertions, 12 deletions
diff --git a/drivers/i2c/busses/i2c-i801.c b/drivers/i2c/busses/i2c-i801.c index 07d0c9565fc5..ae2945a5e007 100644 --- a/drivers/i2c/busses/i2c-i801.c +++ b/drivers/i2c/busses/i2c-i801.c @@ -2,7 +2,7 @@ Copyright (c) 1998 - 2002 Frodo Looijaard <frodol@dds.nl>, Philip Edelbrock <phil@netroedge.com>, and Mark D. Studebaker <mdsxyz123@yahoo.com> - Copyright (C) 2007, 2008 Jean Delvare <khali@linux-fr.org> + Copyright (C) 2007 - 2012 Jean Delvare <khali@linux-fr.org> Copyright (C) 2010 Intel Corporation, David Woodhouse <dwmw2@infradead.org> @@ -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_priv *priv, int status, int timeout) 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_priv *priv, int xact) /* 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_priv *priv) 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_by_byte(struct i801_priv *priv, /* 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; |