On Fri, Jun 07, 2013 at 10:51:23AM +0200, Christian Ruppert wrote: > The designware block is not always properly disabled in the case of > transfer errors. Interrupts from aborted transfers might be handled > after the data structures for the following transfer are initialised but > before the hardware is set up. This can corrupt the data structures to > the point that the system is stuck in an infinite interrupt loop (where > FIFOs are never emptied because dev->msg_read_idx == dev->msgs_num). > > This patch cleanly disables the designware-i2c hardware at the end of > every transfer, be it successful or not. > > This patch requires https://patchwork.kernel.org/patch/2601241/ to be > applied first.
These last two lines should be below "---".
>
> Signed-off-by: Christian Ruppert <christian.rupp...@abilis.com>
> ---
> drivers/i2c/busses/i2c-designware-core.c | 10 ++++++++--
> 1 files changed, 8 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-designware-core.c
> b/drivers/i2c/busses/i2c-designware-core.c
> index b75d292..55a9991 100644
> --- a/drivers/i2c/busses/i2c-designware-core.c
> +++ b/drivers/i2c/busses/i2c-designware-core.c
> @@ -588,11 +588,19 @@ i2c_dw_xfer(struct i2c_adapter *adap, struct i2c_msg
> msgs[], int num)
> ret = wait_for_completion_timeout(&dev->cmd_complete, HZ);
> if (ret == 0) {
> dev_err(dev->dev, "controller timed out\n");
> + /* i2c_dw_init implicitly disables the adapter */
> i2c_dw_init(dev);
> ret = -ETIMEDOUT;
> goto done;
> }
>
> + /*
> + * We must disable the adapter before unlocking the &dev->lock mutex
> + * below. Otherwise the hardware might continue generating interrupts
> + * which in turn causes a race condition with the following transfer.
I added "Needs some more investigation if the additional interrupts are
a hardware bug or this driver doesn't handle them correctly yet." to the
comment and
Applied to for-next, thanks!
BTW since I am currently here: i2c-designware-core should be in the
'algos' directory, no?
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