On Sun, 6 Dec 2020, Ahmed S. Darwish wrote: > NCR5380_poll_politely2() uses in_interrupt() and irqs_disabled() to > check if it is safe to sleep. > > Such usage in drivers is phased out and Linus clearly requested that > code which changes behaviour depending on context should either be > separated, or the context be explicitly conveyed in an argument passed > by the caller. > > Below is a context analysis of NCR5380_poll_politely2() uppermost > callers: > > - NCR5380_maybe_reset_bus(), task, invoked during device probe. > -> NCR5380_poll_politely() > -> do_abort() > > - NCR5380_select(), task, but can only sleep in the "release, then > re-acquire" regions of the spinlock held by its caller. > Sleeping invocations (lock released): > -> NCR5380_poll_politely2() > > Atomic invocations (lock acquired): > -> NCR5380_reselect() > -> NCR5380_poll_politely() > -> do_abort() > -> NCR5380_transfer_pio() > > - NCR5380_intr(), interrupt handler > -> NCR5380_dma_complete() > -> NCR5380_transfer_pio() > -> NCR5380_poll_politely() > -> NCR5380_reselect() (see above) > > - NCR5380_information_transfer(), task, but can only sleep in the > "release, then re-acquire" regions of the caller-held spinlock. > Sleeping invocations (lock released): > - NCR5380_transfer_pio() -> NCR5380_poll_politely() > - NCR5380_poll_politely() > > Atomic invocations (lock acquired): > - NCR5380_transfer_dma() > -> NCR5380_dma_recv_setup() > => generic_NCR5380_precv() -> NCR5380_poll_politely() > => macscsi_pread() -> NCR5380_poll_politely() > > -> NCR5380_dma_send_setup() > => generic_NCR5380_psend -> NCR5380_poll_politely2() > => macscsi_pwrite() -> NCR5380_poll_politely() > > -> NCR5380_poll_politely2() > -> NCR5380_dma_complete() > -> NCR5380_transfer_pio() > -> NCR5380_poll_politely() > - NCR5380_transfer_pio() -> NCR5380_poll_politely > > - NCR5380_reselect(), atomic, always called with hostdata spinlock > held. > > Since NCR5380_poll_politely2() already takes a "wait" argument in > jiffies, use it to determine if the function can sleep. Modify atomic > callers, which passed an unused wait value in terms of HZ, to pass zero. > > Suggested-by: Finn Thain <fthain@xxxxxxxxxxxxxxxxxxx> > Co-developed-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx> > Signed-off-by: Ahmed S. Darwish <a.darwish@xxxxxxxxxxxxx> > Cc: Michael Schmitz <schmitzmic@xxxxxxxxx> > Cc: <linux-m68k@xxxxxxxxxxxxxxxxxxxx> Acked-by: Finn Thain <fthain@xxxxxxxxxxxxxxxxxxx>
