The piix4 i2c driver is extremely slow. Replacing msleep() with usleep_range() increases its speed substantially.
Signed-off-by: Guenter Roeck <[email protected]> --- drivers/i2c/busses/i2c-piix4.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/i2c/busses/i2c-piix4.c b/drivers/i2c/busses/i2c-piix4.c index 78dd5951d6e7..52a8b1c5c110 100644 --- a/drivers/i2c/busses/i2c-piix4.c +++ b/drivers/i2c/busses/i2c-piix4.c @@ -467,13 +467,13 @@ static int piix4_transaction(struct i2c_adapter *piix4_adapter) /* We will always wait for a fraction of a second! (See PIIX4 docs errata) */ if (srvrworks_csb5_delay) /* Extra delay for SERVERWORKS_CSB5 */ - msleep(2); + usleep_range(2000, 2000); else - msleep(1); + usleep_range(500, 1000); while ((++timeout < MAX_TIMEOUT) && ((temp = inb_p(SMBHSTSTS)) & 0x01)) - msleep(1); + usleep_range(200, 500); /* If the SMBus is still busy, we give up */ if (timeout == MAX_TIMEOUT) { -- 2.7.4
