Message ID | 2583975.4sIyE3leJj@kreacher (mailing list archive) |
---|---|
State | New, archived |
Delegated to: | Bjorn Helgaas |
Headers | show |
Series | nvme-pci: Allow PCI bus-level PM to be used if ASPM is disabled | expand |
> - 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.
On Thu, Aug 8, 2019 at 10:48 AM Christoph Hellwig <hch@lst.de> wrote: > > > - 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. Now that I think of that, it appears redundant. I'll drop 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? That can be done. > > @@ -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? OK > > +{ > > + 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. Right, sorry. > > + > > + > > #ifdef CONFIG_PCIEASPM_DEBUG > > Nit: double blank line here. Overlooked, will fix. Thanks!
Index: linux-pm/drivers/nvme/host/pci.c =================================================================== --- linux-pm.orig/drivers/nvme/host/pci.c +++ linux-pm/drivers/nvme/host/pci.c @@ -2846,7 +2846,7 @@ static int nvme_resume(struct device *de struct nvme_dev *ndev = pci_get_drvdata(to_pci_dev(dev)); struct nvme_ctrl *ctrl = &ndev->ctrl; - if (pm_resume_via_firmware() || !ctrl->npss || + if (ndev->last_ps == U32_MAX || nvme_set_power_state(ctrl, ndev->last_ps) != 0) nvme_reset_ctrl(ctrl); return 0; @@ -2859,6 +2859,8 @@ static int nvme_suspend(struct device *d struct nvme_ctrl *ctrl = &ndev->ctrl; int ret = -EBUSY; + ndev->last_ps = U32_MAX; + /* * The platform does not remove power for a kernel managed suspend so * use host managed nvme power settings for lowest idle power if @@ -2866,8 +2868,14 @@ static int nvme_suspend(struct device *d * shutdown. But if the firmware is involved after the suspend or the * device does not support any non-default power states, shut down the * device fully. + * + * If ASPM is not enabled for the device, shut down the device and allow + * the PCI bus layer to put it into D3 in order to take the PCIe link + * down, so as to allow the platform to achieve its minimum low-power + * state (which may not be possible if the link is up). */ - if (pm_suspend_via_firmware() || !ctrl->npss) { + if (pm_suspend_via_firmware() || !ctrl->npss || + !pcie_aspm_enabled(pdev)) { nvme_dev_disable(ndev, true); return 0; } @@ -2880,9 +2888,8 @@ static int nvme_suspend(struct device *d ctrl->state != NVME_CTRL_ADMIN_ONLY) goto unfreeze; - ndev->last_ps = 0; ret = nvme_get_power_state(ctrl, &ndev->last_ps); - if (ret < 0) + if (ret < 0 || ndev->last_ps == U32_MAX) goto unfreeze; ret = nvme_set_power_state(ctrl, ctrl->npss); Index: linux-pm/drivers/pci/pcie/aspm.c =================================================================== --- linux-pm.orig/drivers/pci/pcie/aspm.c +++ linux-pm/drivers/pci/pcie/aspm.c @@ -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) +{ + 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; +} + + #ifdef CONFIG_PCIEASPM_DEBUG static ssize_t link_state_show(struct device *dev, struct device_attribute *attr, Index: linux-pm/include/linux/pci.h =================================================================== --- linux-pm.orig/include/linux/pci.h +++ linux-pm/include/linux/pci.h @@ -1567,8 +1567,10 @@ extern bool pcie_ports_native; #ifdef CONFIG_PCIEASPM bool pcie_aspm_support_enabled(void); +u32 pcie_aspm_enabled(struct pci_dev *pci_device); #else static inline bool pcie_aspm_support_enabled(void) { return false; } +static inline u32 pcie_aspm_enabled(struct pci_dev *pci_device) { return 0; } #endif #ifdef CONFIG_PCIEAER