Messages in this thread | | | From | Stephen Boyd <> | Date | Tue, 5 Sep 2023 17:27:23 -0500 | Subject | Re: [PATCH 1/3] platform/x86: intel_scu_ipc: Check status after timeouts in busy_loop() |
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Quoting Mika Westerberg (2023-08-31 22:50:11) > 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)) > > How can the status bit change here as we are the only user and the SCU > access is serialized by ipclock?
I don't know how the SCU works. I thought that IPC_STATUS_BUSY bit was cleared by the SCU when it was done processing. With that assumption, I tried to show that the status is read and then the process schedules away for a long time and has an outdated view of the busy bit.
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