Hello Ulrik, Jagadeesh,
On Mon, 22 Jun 2009, Ulrik Bech Hald wrote:
> Under certain rare conditions, I2C_STAT[13].RDR bit may be set,
> and the corresponding interrupt fire, even when there is no
> data in the receive FIFO, or the I2C data transfer is still
> ongoing. These spurious RDR events must be ignored by the
> software.
>
> A check for OMAP_I2C_STAT_BB is introduced in the ISR to
> prevent further processing of RDR interrupt, if the bus is busy.
>
> Signed-off-by: Ulrik Bech Hald <u...@ti.com>
> Signed-off-by: Jagadeesh Bhaskar Pakaravoor <j-pakarav...@ti.com>
> ---
> drivers/i2c/busses/i2c-omap.c | 9 +++++++++
> 1 files changed, 9 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
> index ece0125..88feea1 100644
> --- a/drivers/i2c/busses/i2c-omap.c
> +++ b/drivers/i2c/busses/i2c-omap.c
> @@ -668,6 +668,15 @@ omap_i2c_isr(int this_irq, void *dev_id)
> omap_i2c_complete_cmd(dev, err);
> if (stat & (OMAP_I2C_STAT_RRDY | OMAP_I2C_STAT_RDR)) {
> u8 num_bytes = 1;
> + /* 3430 I2C Errata 1.15
> + * RDR could be set when the bus is busy, then
> + * ignore the interrupt, and clear the bit.
> + */
> + u8 stat2 = 0;
> + stat2 = omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG);
> + if (stat2 & OMAP_I2C_STAT_BB)
> + return IRQ_HANDLED;
Why use stat2? Why not just test stat again?
> +
> if (dev->fifo_size) {
> if (stat & OMAP_I2C_STAT_RRDY)
> num_bytes = dev->fifo_size;
> --
> 1.5.4.3
>
> --
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>
- Paul
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