On Sat, Dec 30, 2017 at 08:50:58AM -0800, Guenter Roeck wrote:
> The piix4 i2c driver is extremely slow. Replacing msleep()
> with usleep_range() increases its speed substantially.
>
> Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>
Any comments or concerns ?
Thanks,
Guenter
> ---
> 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) {
