On Fri, 13 Dec 2019 14:34:13 +0100, Takashi Iwai wrote: > > On Fri, 13 Dec 2019 14:05:31 +0100, > Kai Vehmanen wrote: > > > > Hey, > > > > On Tue, 10 Dec 2019, Takashi Iwai wrote: > > > > > This patch attempts to improve the situation by introducing the > > > standard waitqueue in the RIRB waiter side instead of polling. The > > > > this patch was part of the testing as well, so looks good. One minor > > nit only: > > > > > @@ -216,6 +216,9 @@ void snd_hdac_bus_update_rirb(struct hdac_bus *bus) > > > else if (bus->rirb.cmds[addr]) { > > > bus->rirb.res[addr] = res; > > > bus->rirb.cmds[addr]--; > > > + if (!bus->rirb.cmds[addr] && > > > + waitqueue_active(&bus->rirb_wq)) > > > + wake_up(&bus->rirb_wq); > > > > Checkpath would like to have a comment here: > > > > WARNING: waitqueue_active without comment > > #77: FILE: sound/hda/hdac_controller.c:220: > > + waitqueue_active(&bus->rirb_wq)) > > Yeah, that was known to me, too. Actually it's misleading; what > actually matters is the memory barrier or other synchronization there, > and this should work as is because of the current code path. > (Besides, majority of existing waitqueue_active() have no comments at > all :) > > And, now I found wa_has_sleeper() as a better replacement of > waitqueue_active() that explicitly cares about synchronization. > So I'll change with this in a later patch (after unification to > hda-core). On the second thought, the extra barrier should be utterly superfluous, so I'll go for commenting about the spinlock instead... Takashi _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx https://mailman.alsa-project.org/mailman/listinfo/alsa-devel