Quoting Andy Shevchenko (2023-08-31 06:53:14) > 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? I have no idea if that happens in early stages. What about suspend/resume though? I suppose timekeeping could be suspended in that case, so we can't really check anything with ktime. I can rework this patch to simply recheck the busy bit so that we don't have to figure out if the code is called early or from suspend paths.
