pipeline:make the IPC API atomic.

[ghost]

make the IPC API atomic, to avoid the interruption of
the scheduled pipeline.

Signed-off-by: Wu Zhigang zhigang.wu@linux.intel.com

[lgirdwood]

The code changes look correct if we have to make prepare() atomic. However, I'm not following the commit message comments. Can you add more detail to each step above, include numbers on newlines like 1), 2) etc to make it easy to follow. Thanks

[ghost]

ok, I will change the comment and upload the patch again.

[ghost]

update the comment already. please check it.

[lgirdwood]

Ok, so I assume we have a race with the IPC interrupt when handling XRUNs ?
Is this fixing a real bug today or just fixing a potential race ?

[ghost]

This is just fixing a potential race.
It is similarly as what i sent a patch before: 9112ee5

[lgirdwood]

ok, so pipeline APIs are called by IPC handler (which is serialized and only called in idle state) and internally for XRUN and copy(). XRUN handler should be atomic (IRQs off) alongside the other IPC pipeline APIs.

[ghost]

exactly! this patch is good for the stress test.

[lgirdwood]

please rename the PR and message to reflect the agreed changes alongside the new patches..

[ghost]

update the PR and message already.

[lgirdwood]

This patch should also make the other pipeline APIs called by IPC atomic. e.g.params and reset

[ghost]

I will do this after back to office.

[ghost]

updated the code and message already.
please check.

[jiawang6]

CI observed building failure.

Failed Platform: baytrail apollolake cannonlake

configure: error: in `/build/sof/src':
configure: error: C compiler cannot create executables

[lgirdwood]

@jiawang6 I think your CI is broken as this patch builds for me and has nothing todo with autotools.