On Thu, Aug 6, 2015 at 3:22 PM, Eddie Huang <eddie.huang@xxxxxxxxxxxx> wrote:
> When occur i2c ack error, i2c controller generate two interrupts,
> first is the ack error interrupt, then the complete interrupt.
> i2c interrupt handler should keep the two interrupt value, and only
> call complete() for the complete interrupt.
>
> Signed-off-by: Liguo Zhang <liguo.zhang@xxxxxxxxxxxx>
> Signed-off-by: Eddie Huang <eddie.huang@xxxxxxxxxxxx>
Reviewed-by: Daniel Kurtz <djkurtz@xxxxxxxxxxxx>
> ---
> drivers/i2c/busses/i2c-mt65xx.c | 15 +++++++++++----
> 1 file changed, 11 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-mt65xx.c b/drivers/i2c/busses/i2c-mt65xx.c
> index e28ad4c..c02e6c0 100644
> --- a/drivers/i2c/busses/i2c-mt65xx.c
> +++ b/drivers/i2c/busses/i2c-mt65xx.c
> @@ -557,15 +557,22 @@ static irqreturn_t mtk_i2c_irq(int irqno, void *dev_id)
> {
> struct mtk_i2c *i2c = dev_id;
> u16 restart_flag = 0;
> + u16 intr_stat;
>
> if (i2c->dev_comp->auto_restart)
> restart_flag = I2C_RS_TRANSFER;
>
> - i2c->irq_stat = readw(i2c->base + OFFSET_INTR_STAT);
> - writew(restart_flag | I2C_HS_NACKERR | I2C_ACKERR
> - | I2C_TRANSAC_COMP, i2c->base + OFFSET_INTR_STAT);
> + intr_stat = readw(i2c->base + OFFSET_INTR_STAT);
> + writew(intr_stat, i2c->base + OFFSET_INTR_STAT);
>
> - complete(&i2c->msg_complete);
> + /*
> + * when occurs ack error, i2c controller generate two interrupts
> + * first is the ack error interrupt, then the complete interrupt
> + * i2c->irq_stat need keep the two interrupt value.
> + */
> + i2c->irq_stat |= intr_stat;
> + if (i2c->irq_stat & (I2C_TRANSAC_COMP | restart_flag))
> + complete(&i2c->msg_complete);
>
> return IRQ_HANDLED;
> }
> --
> 1.7.9.5
>
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