Re: [PATCH 1/3] platform/x86: intel_scu_ipc: Check status after timeouts in busy_loop()

[Andy Shevchenko]

On Wed, Aug 30, 2023 at 06:14:01PM -0700, Stephen Boyd wrote:
> It's possible for the polling loop in busy_loop() to get scheduled away
> for a long time.
> 
>   status = ipc_read_status(scu);
>   <long time scheduled away>
>   if (!(status & IPC_STATUS_BUSY))
> 
> If this happens, then the status bit could change and this function
> would never test it again after checking the jiffies against the timeout
> limit. Polling code should check the condition one more time after the
> timeout in case this happens.
> 
> The read_poll_timeout() helper implements this logic, and is shorter, so
> simply use that helper here.

I don't remember by heart, but on some older Intel hardware this might have
been called during early stages where ktime() is not functional yet.

Is this still a case here?

...

Codewise change looks good to me.

-- 
With Best Regards,
Andy Shevchenko