Messages in this thread Patch in this message | | | Date | Sat, 7 Jul 2018 15:38:15 +0200 | From | Lukas Wunner <> | Subject | Re: [PATCH 5/5] thunderbolt: Add support for runtime PM |
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On Mon, Jun 18, 2018 at 02:07:31PM +0300, Mika Westerberg wrote: > --- a/drivers/thunderbolt/domain.c > +++ b/drivers/thunderbolt/domain.c > @@ -132,6 +133,8 @@ static ssize_t boot_acl_show(struct device *dev, struct device_attribute *attr, > if (!uuids) > return -ENOMEM; > > + pm_runtime_get_sync(&tb->dev); > + > if (mutex_lock_interruptible(&tb->lock)) { > ret = -ERESTARTSYS; > goto out; [snip] > @@ -426,6 +437,13 @@ int tb_domain_add(struct tb *tb) > /* This starts event processing */ > mutex_unlock(&tb->lock); > > + pm_runtime_no_callbacks(&tb->dev); > + pm_runtime_set_active(&tb->dev); > + pm_runtime_enable(&tb->dev); > + pm_runtime_set_autosuspend_delay(&tb->dev, TB_AUTOSUSPEND_DELAY); > + pm_runtime_mark_last_busy(&tb->dev); > + pm_runtime_use_autosuspend(&tb->dev); > + > return 0; > > err_domain_del:
You're setting pm_runtime_no_callbacks() on the domain. A side effect of setting this flag is that whenever the domain's device is runtime resumed, it's parent (the NHI) is *not* runtime resumed, see this comment in rpm_resume():
/* * See if we can skip waking up the parent. This is safe only if * power.no_callbacks is set, because otherwise we don't know whether * the resume will actually succeed. */
Above, you're runtime resuming the domain in boot_acl_show(). So if the NHI is runtime suspended while that sysfs attribute is accessed, it won't be runtime resumed. Is that actually what you want?
> @@ -514,6 +532,28 @@ void tb_domain_complete(struct tb *tb) > tb->cm_ops->complete(tb); > } > > +int tb_domain_runtime_suspend(struct tb *tb) > +{ > + if (tb->cm_ops->runtime_suspend) { > + int ret = tb->cm_ops->runtime_suspend(tb); > + if (ret) > + return ret; > + } > + tb_ctl_stop(tb->ctl); > + return 0; > +} > + > +int tb_domain_runtime_resume(struct tb *tb) > +{ > + tb_ctl_start(tb->ctl); > + if (tb->cm_ops->runtime_resume) { > + int ret = tb->cm_ops->runtime_resume(tb); > + if (ret) > + return ret; > + } > + return 0; > +} > + > /** > * tb_domain_approve_switch() - Approve switch > * @tb: Domain the switch belongs to > --- a/drivers/thunderbolt/nhi.c > +++ b/drivers/thunderbolt/nhi.c > @@ -900,7 +900,32 @@ static void nhi_complete(struct device *dev) > struct pci_dev *pdev = to_pci_dev(dev); > struct tb *tb = pci_get_drvdata(pdev); > > - tb_domain_complete(tb); > + /* > + * If we were runtime suspended when system suspend started, > + * schedule runtime resume now. It should bring the domain back > + * to functional state. > + */ > + if (pm_runtime_suspended(&pdev->dev)) > + pm_runtime_resume(&pdev->dev); > + else > + tb_domain_complete(tb); > +} > + > +static int nhi_runtime_suspend(struct device *dev) > +{ > + struct pci_dev *pdev = to_pci_dev(dev); > + struct tb *tb = pci_get_drvdata(pdev); > + > + return tb_domain_runtime_suspend(tb); > +} > + > +static int nhi_runtime_resume(struct device *dev) > +{ > + struct pci_dev *pdev = to_pci_dev(dev); > + struct tb *tb = pci_get_drvdata(pdev); > + > + nhi_enable_int_throttling(tb->nhi); > + return tb_domain_runtime_resume(tb); > }
You're invoking tb_domain_runtime_suspend() from nhi_runtime_suspend(), same for ->runtime_resume.
Wouldn't it make more sense to make tb_domain_runtime_suspend() the ->runtime_suspend callback of the domain instead of mixing it together with NHI runtime suspend?
BTW, what's the purpose of nhi_enable_int_throttling()?
> --- a/drivers/thunderbolt/switch.c > +++ b/drivers/thunderbolt/switch.c > +/* > + * Currently only need to provide the callbacks. Everything else is handled > + * in the connection manager. > + */ > +static int __maybe_unused tb_switch_runtime_suspend(struct device *dev) > +{ > + return 0; > +} > + > +static int __maybe_unused tb_switch_runtime_resume(struct device *dev) > +{ > + return 0; > +} > + > +static const struct dev_pm_ops tb_switch_pm_ops = { > + SET_RUNTIME_PM_OPS(tb_switch_runtime_suspend, tb_switch_runtime_resume, > + NULL) > +}; > + > struct device_type tb_switch_type = { > .name = "thunderbolt_device", > .release = tb_switch_release, > + .pm = &tb_switch_pm_ops, > };
Looking at the call sites of RPM_GET_CALLBACK(), I'm under the impression that if no callbacks are defined, the PM core will simply assume success. Then you don't need to define any PM callbacks for tb_switch. Am I missing something? Thanks,
Lukas
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