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: <sta...@vger.kernel.org> # v3.7+
here and resend, so it gets backported to older kernels.
> Signed-off-by: Alexander Kochetkov <al.koc...@gmail.com>
> ---
> 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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