On Sat, Nov 15, 2014 at 05:20:51AM +0400, Alexander Kochetkov wrote:
> commit 1d7afc95946487945cc7f5019b41255b72224b70 (i2c: omap: ack IRQ in parts)
> changed the interrupt handler to complete transfers without clearing
> XRDY (AL case) and ARDY (NACK case) flags. XRDY or ARDY interrupt will be
> fired again (in parallel with omap_i2c_xfer_msg). Interrupt handler will
> complete transfers second time. As a result, NACK and AL transfers
> terminates with "transfer timeout" and sometimes client code segfault.
>
> The patch restore original logic of handling NACK and AL interrupts and
> fix race between interrupt handler and omap_i2c_xfer_msg (for AL and
> NACK case only).
>
> Tested on Beagleboard XM C.
>
Assuming this is really correct (I haven't tested), you need to add:
Fixes: 1d7afc9 i2c: omap: ack IRQ in parts
Cc: <stable@xxxxxxxxxxxxxxx> # v3.7+
here and resend, so it gets backported to older kernels.
> Signed-off-by: Alexander Kochetkov <al.kochet@xxxxxxxxx>
> ---
> drivers/i2c/busses/i2c-omap.c | 2 --
> 1 file changed, 2 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
> index 90dcc2e..9af7095 100644
> --- a/drivers/i2c/busses/i2c-omap.c
> +++ b/drivers/i2c/busses/i2c-omap.c
> @@ -926,14 +926,12 @@ omap_i2c_isr_thread(int this_irq, void *dev_id)
> if (stat & OMAP_I2C_STAT_NACK) {
> err |= OMAP_I2C_STAT_NACK;
> omap_i2c_ack_stat(dev, OMAP_I2C_STAT_NACK);
> - break;
> }
>
> if (stat & OMAP_I2C_STAT_AL) {
> dev_err(dev->dev, "Arbitration lost\n");
> err |= OMAP_I2C_STAT_AL;
> omap_i2c_ack_stat(dev, OMAP_I2C_STAT_AL);
> - break;
> }
>
> /*
> --
> 1.7.9.5
>
--
balbi
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