Quoting Andy Shevchenko (2023-09-11 14:17:22) > On Mon, Sep 11, 2023 at 12:39:33PM -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); // status = IPC_STATUS_BUSY > > <long time scheduled away> > > if (!(status & IPC_STATUS_BUSY)) > > > > If this happens, then the status bit could change while the task is > > scheduled away and this function would never read the status again after > > timing out. Instead, the function will return -ETIMEDOUT when it's > > possible that scheduling didn't work out and the status bit was cleared. > > Bit polling code should always check the bit being polled one more time > > after the timeout in case this happens. > > > > Fix this by reading the status once more after the while loop breaks. > > The read_poll_timeout() macro implements all of this, and it is > > shorter, so use that macro here to consolidate code and fix this. > > > > There were some concerns with using read_poll_timeout() because it uses > > timekeeping, and timekeeping isn't running early on or during the late > > stages of system suspend or early stages of system resume, but an audit > > of the code concluded that this code isn't called during those times so > > it is safe to use the macro. > > ... > > > + err = read_poll_timeout(ipc_read_status, status, !(status & IPC_STATUS_BUSY), > > + 100, jiffies_to_usecs(IPC_TIMEOUT), false, scu); > > Since "false" you probably can utilize readx_poll_timeout(). > You mean 'addr' will be 'scu'? Ok.
