On Mon, Sep 11, 2023 at 12:39:34PM -0700, Stephen Boyd wrote: > It's possible for the completion in ipc_wait_for_interrupt() to timeout, > simply because the interrupt was delayed in being processed. A timeout > in itself is not an error. This driver should check the status register > upon a timeout to ensure that scheduling or interrupt processing delays > don't affect the outcome of the IPC return value. > > CPU0 SCU > ---- --- > ipc_wait_for_interrupt() > wait_for_completion_timeout(&scu->cmd_complete) > [TIMEOUT] status[IPC_STATUS_BUSY]=0 > > Fix this problem by reading the status bit in all cases, regardless of > the timeout. If the completion times out, we'll assume the problem was > that the IPC_STATUS_BUSY bit was still set, but if the status bit is > cleared in the meantime we know that we hit some scheduling delay and we > should just check the error bit. > > Cc: Prashant Malani <pmalani@xxxxxxxxxxxx> > Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx> > Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> Reviewed-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
