On Fri, 06 Feb 2009 14:11:46 +0100, Roel Kluin wrote:
> Let's first adress the other issues at hand.
> This patch should be applied on top of my previous cleanup patch
Agreed.
>
> --------------------------->8---------------------8<---------------------------
> With a postfix decrement these timeouts reach -1 rather than 0, but after the
> loop it is tested whether they have become 0.
>
> As pointed out by Jean Delvare, the msg_num should be tested before the timeout.
> With the current order, you could exit with a timeout error while all the
> messages were successfully transferred.
>
> Signed-off-by: Roel Kluin <roel.kluin@xxxxxxxxx>
> ---
> diff --git a/drivers/i2c/algos/i2c-algo-pcf.c b/drivers/i2c/algos/i2c-algo-pcf.c
> index ce916d7..2862f11 100644
> --- a/drivers/i2c/algos/i2c-algo-pcf.c
> +++ b/drivers/i2c/algos/i2c-algo-pcf.c
> @@ -115,15 +115,17 @@ static int wait_for_bb(struct i2c_algo_pcf_data *adap)
>
> status = get_pcf(adap, 1);
>
> - while (timeout-- && !(status & I2C_PCF_BB)) {
> + while (!(status & I2C_PCF_BB) && --timeout) {
> udelay(100); /* wait for 100 us */
> status = get_pcf(adap, 1);
> }
>
> - if (timeout <= 0)
> + if (timeout == 0) {
> printk(KERN_ERR "Timeout waiting for Bus Busy\n");
> + return -ETIMEDOUT;
> + }
>
> - return timeout <= 0;
> + return 0;
> }
>
> static int wait_for_pin(struct i2c_algo_pcf_data *adap, int *status)
> @@ -133,7 +135,7 @@ static int wait_for_pin(struct i2c_algo_pcf_data *adap, int *status)
>
> *status = get_pcf(adap, 1);
>
> - while (timeout-- && (*status & I2C_PCF_PIN)) {
> + while ((*status & I2C_PCF_PIN) && --timeout) {
> adap->waitforpin(adap->data);
> *status = get_pcf(adap, 1);
> }
> @@ -142,10 +144,10 @@ static int wait_for_pin(struct i2c_algo_pcf_data *adap, int *status)
> return -EINTR;
> }
>
> - if (timeout <= 0)
> - return -1;
> - else
> - return 0;
> + if (timeout == 0)
> + return -ETIMEDOUT;
> +
> + return 0;
> }
>
> /*
Applied, thanks. It would be great if Eric (or anyone with a
PCF8584-based adapter) could test the two patches, just to make sure we
didn't accidentally break anything:
ftp://ftp.kernel.org/pub/linux/kernel/people/jdelvare/linux-2.6/jdelvare-i2c/i2c-algo-pcf-01-style-cleanups.patch
ftp://ftp.kernel.org/pub/linux/kernel/people/jdelvare/linux-2.6/jdelvare-i2c/i2c-algo-pcf-02-handle-timeout-correctly.patch
--
Jean Delvare
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