Messages in this thread | | | Date | Thu, 8 Aug 2019 10:48:04 +0200 | From | Christoph Hellwig <> | Subject | Re: [PATCH] nvme-pci: Allow PCI bus-level PM to be used if ASPM is disabled |
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> - ndev->last_ps = 0; > ret = nvme_get_power_state(ctrl, &ndev->last_ps); > - if (ret < 0) > + if (ret < 0 || ndev->last_ps == U32_MAX)
Is the intent of the magic U32_MAX check to see if the nvme_get_power_state failed at the nvme level? In that case just checking for any non-zero return value from nvme_get_power_state might be the easier and more clear way to do it.
> Index: linux-pm/drivers/pci/pcie/aspm.c > =================================================================== > --- linux-pm.orig/drivers/pci/pcie/aspm.c > +++ linux-pm/drivers/pci/pcie/aspm.c
Shouldn't we split PCI vs nvme in two patches?
> @@ -1170,6 +1170,26 @@ static int pcie_aspm_get_policy(char *bu > module_param_call(policy, pcie_aspm_set_policy, pcie_aspm_get_policy, > NULL, 0644); > > +/* > + * pcie_aspm_enabled - Return the mask of enabled ASPM link states. > + * @pci_device: Target device. > + */ > +u32 pcie_aspm_enabled(struct pci_dev *pci_device)
pcie_aspm_enabled sounds like it returns a boolean. Shouldn't there be a mask or so in the name better documenting what it returns?
> +{ > + struct pci_dev *bridge = pci_upstream_bridge(pci_device); > + u32 ret; > + > + if (!bridge) > + return 0; > + > + mutex_lock(&aspm_lock); > + ret = bridge->link_state ? bridge->link_state->aspm_enabled : 0; > + mutex_unlock(&aspm_lock); > + > + return ret; > +}
I think this will need a EXPORT_SYMBOL_GPL thrown in so that modular nvme continues working.
> + > + > #ifdef CONFIG_PCIEASPM_DEBUG
Nit: double blank line here.
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