On Thu, Nov 25, 2010 at 5:20 AM, Sebastian Andrzej Siewior
<bigeasy@xxxxxxxxxxxxx> wrote:
> I haven't seen this (yet) during a normal transfer but starting
> i2cdetect seems to hang the bus. On my Sodaville board, i2cdetect runs
> fine on bus zero and runs into timeouts on bus one and two. The chip
> never recovers from this condition. The following transfers hang as
> well. The ISR_UB never disappears.
> Issuing a chip reset fixes the timeout and following transfer succeed.
>
> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
> Signed-off-by: Dirk Brandewie <dirk.brandewie@xxxxxxxxx>
> ---
> drivers/i2c/busses/i2c-pxa.c | 35 +++++++++++++++++++----------------
> 1 files changed, 19 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-pxa.c b/drivers/i2c/busses/i2c-pxa.c
> index bd4b885..1a48470 100644
> --- a/drivers/i2c/busses/i2c-pxa.c
> +++ b/drivers/i2c/busses/i2c-pxa.c
> @@ -257,23 +257,7 @@ static void i2c_pxa_abort(struct pxa_i2c *i2c)
> _ICR(i2c));
> }
>
> -static int i2c_pxa_wait_bus_not_busy(struct pxa_i2c *i2c)
> -{
> - int timeout = DEF_TIMEOUT;
>
> - while (timeout-- && readl(_ISR(i2c)) & (ISR_IBB | ISR_UB)) {
> - if ((readl(_ISR(i2c)) & ISR_SAD) != 0)
> - timeout += 4;
> -
> - msleep(2);
> - show_state(i2c);
> - }
> -
> - if (timeout < 0)
> - show_state(i2c);
> -
> - return timeout < 0 ? I2C_RETRY : 0;
> -}
>
> static int i2c_pxa_wait_master(struct pxa_i2c *i2c)
> {
> @@ -425,6 +409,25 @@ static void i2c_pxa_reset(struct pxa_i2c *i2c)
> udelay(100);
> }
>
> +static int i2c_pxa_wait_bus_not_busy(struct pxa_i2c *i2c)
> +{
> + int timeout = DEF_TIMEOUT;
> +
> + while (timeout-- && readl(_ISR(i2c)) & (ISR_IBB | ISR_UB)) {
> + if ((readl(_ISR(i2c)) & ISR_SAD) != 0)
> + timeout += 4;
> +
> + msleep(2);
> + show_state(i2c);
> + }
> +
> + if (timeout < 0) {
> + show_state(i2c);
> + i2c_pxa_reset(i2c);
> + }
Even you reset I2C controller, it shouldn't help you since bus isn't
free. I thinkt that you should reset I2C bus before you reseting I2C
controller.
> +
> + return timeout < 0 ? I2C_RETRY : 0;
> +}
>
> #ifdef CONFIG_I2C_PXA_SLAVE
> /*
> --
> 1.7.3.2
>
>
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