Re: firewire: use sleepable workqueue to handle 1394 OHCI IT/IR context events: test 1
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From: Takashi S. <o-t...@sa...> - 2024-09-05 08:18:33
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Hi, Thanks for your test. On Wed, Sep 04, 2024 at 08:45:51PM +0000, Edmund Raile wrote: > Hello Sakamoto-San, I very much appreciate the idea and effort to take on the tasklet conversion in small steps instead of all-at-once! > > I also thank you for the CC, I'd like to be the testing canary for the coal mine of firewire ALSA with RME FireFace! > The ALSA mailing list is a bit overwhelming and I'll likely unsubscribe so a direct CC for anything I can test is a good idea. > > Trying to apply patch 1 of 5 to mainline, your kernel tree appears to be out of sync with mainline! > It was missing b171e20 from 2009 and a7ecbe9 from 2022! > I hope nothing else important is missing! Yes. The series of changes is prepared for the next merge window to v6.12 kernel. It is on the top of for-next branch in linux1394 tree. You can see some patches on v6.12-rc2 tag. https://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394.git/log/?h=for-next > Since in fw_card_initialize, ret is tested to be 0 we'd need an else instead, is this correct? > > I edited these functions of patch 1, now everything applies just fine: > > @@ -571,11 +571,28 @@ void fw_card_initialize(struct fw_card *card, > } > EXPORT_SYMBOL(fw_card_initialize); > > -int fw_card_add(struct fw_card *card, > - u32 max_receive, u32 link_speed, u64 guid) > +int fw_card_add(struct fw_card *card, u32 max_receive, u32 link_speed, u64 guid, > + unsigned int supported_isoc_contexts) > { > + struct workqueue_struct *isoc_wq; > int ret; > > + // This workqueue should be: > + // * != WQ_BH Sleepable. > + // * == WQ_UNBOUND Any core can process data for isoc context. The > + // implementation of unit protocol could consumes the core > + // longer somehow. > + // * != WQ_MEM_RECLAIM Not used for any backend of block device. > + // * == WQ_HIGHPRI High priority to process semi-realtime timestamped data. > + // * == WQ_SYSFS Parameters are available via sysfs. > + // * max_active == n_it + n_ir A hardIRQ could notify events for multiple isochronous > + // contexts if they are scheduled to the same cycle. > + isoc_wq = alloc_workqueue("firewire-isoc-card%u", > + WQ_UNBOUND | WQ_HIGHPRI | WQ_SYSFS, > + supported_isoc_contexts, card->index); > + if (!isoc_wq) > + return -ENOMEM; > + > card->max_receive = max_receive; > card->link_speed = link_speed; > card->guid = guid; > @@ -584,9 +601,13 @@ int fw_card_add(struct fw_card *card, > > generate_config_rom(card, tmp_config_rom); > ret = card->driver->enable(card, tmp_config_rom, config_rom_length); > if (ret == 0) > list_add_tail(&card->link, &card_list); > + else > + destroy_workqueue(isoc_wq); > + > + card->isoc_wq = isoc_wq; > > mutex_unlock(&card_mutex); > > return ret; > @@ -709,7 +729,9 @@ void fw_core_remove_card(struct fw_card *card) > { > struct fw_card_driver dummy_driver = dummy_driver_template; > unsigned long flags; > > + might_sleep(); > + > card->driver->update_phy_reg(card, 4, > PHY_LINK_ACTIVE | PHY_CONTENDER, 0); > fw_schedule_bus_reset(card, false, true); > @@ -719,6 +741,7 @@ void fw_core_remove_card(struct fw_card *card) > dummy_driver.free_iso_context = card->driver->free_iso_context; > dummy_driver.stop_iso = card->driver->stop_iso; > card->driver = &dummy_driver; > + drain_workqueue(card->isoc_wq); > > spin_lock_irqsave(&card->lock, flags); > fw_destroy_nodes(card); > > Building a kernel with the patch produced 6.11.0-rc6-1-mainline-00019-g67784a74e258-dirty. > Testing it with TI XIO2213B and RME Fireface 800 so far > 1 hour reveals no issues at all. > ALSA streaming works fine: > mpv --audio-device=alsa/sysdefault:CARD=Fireface800 Spor-Ignition.flac > > Though I haven't the faintest clue how to measure CPU usage impact of the patch, it looks like it would be neglible. > > As of finishing this, I noticed you released [2] https://lore.kernel.org/lkml/202...@sa.../T/ > I'll get around to testing that one too, but tomorrow at the earliest. > > Kind regards, > Edmund Raile. > > Signed-off-by: Edmund Raile <edm...@pr...> > Tested-by: Edmund Raile <edm...@pr...> If using v6.11 kernel, it is convenient to use my remote repository to backport changes for v6.12. But let you be careful to the history of changes anyway. * https://github.com/takaswie/linux-firewire-dkms/ Thanks Takashi Sakamoto |