| Message ID | 20240712185418.937087-3-superm1@kernel.org (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | Put XHCI controllers into D3 at S4/S5 | expand |
On 12.7.2024 21.54, superm1@kernel.org wrote: > From: Mario Limonciello <mario.limonciello@amd.com> > > A workaround was put in place for Haswell systems with spurious events > to put XHCI controllers into D3hot at shutdown. This solution actually > makes sense for all XHCI controllers though because XHCI controllers > left in D0 by the OS may remain in D0 when the SoC goes into S5. > > Explicitly put all XHCI controllers into D3hot at shutdown and when > module is unloaded. > > Signed-off-by: Mario Limonciello <mario.limonciello@amd.com> > --- > drivers/usb/host/xhci-pci.c | 8 ++------ > 1 file changed, 2 insertions(+), 6 deletions(-) > > diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c > index 4408d4caf66d2..dde5e4a210719 100644 > --- a/drivers/usb/host/xhci-pci.c > +++ b/drivers/usb/host/xhci-pci.c > @@ -667,9 +667,7 @@ static void xhci_pci_remove(struct pci_dev *dev) > xhci->shared_hcd = NULL; > } > > - /* Workaround for spurious wakeups at shutdown with HSW */ > - if (xhci->quirks & XHCI_SPURIOUS_WAKEUP) > - pci_set_power_state(dev, PCI_D3hot); > + pci_set_power_state(dev, PCI_D3hot); > > usb_hcd_pci_remove(dev); Just noticed these have been the wrong way around for a while (impacting HSW). We should first call usb_hcd_pci_remove() and then pci_set_power_state(D3), otherwise we force a fully running xHC into D3. Note, with this change we end up first calling pci_disable_device(), then pci_set_power_state(D3) > } > @@ -882,9 +880,7 @@ static void xhci_pci_shutdown(struct usb_hcd *hcd) > xhci_shutdown(hcd); > xhci_cleanup_msix(xhci); > > - /* Yet another workaround for spurious wakeups at shutdown with HSW */ > - if (xhci->quirks & XHCI_SPURIOUS_WAKEUP) > - pci_set_power_state(pdev, PCI_D3hot); > + pci_set_power_state(pdev, PCI_D3hot); Looks good Note that we now end up first calling pci_set_power_state(D3) and then pci_disable_device(). The other way around than the remove case above. I don't know if it matters. Thanks Mathias
On 24-07-12 13:54:18, superm1@kernel.org wrote: > From: Mario Limonciello <mario.limonciello@amd.com> > > A workaround was put in place for Haswell systems with spurious events > to put XHCI controllers into D3hot at shutdown. This solution actually > makes sense for all XHCI controllers though because XHCI controllers > left in D0 by the OS may remain in D0 when the SoC goes into S5. > > Explicitly put all XHCI controllers into D3hot at shutdown and when > module is unloaded. > > Signed-off-by: Mario Limonciello <mario.limonciello@amd.com> > --- > drivers/usb/host/xhci-pci.c | 8 ++------ > 1 file changed, 2 insertions(+), 6 deletions(-) > > diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c > index 4408d4caf66d2..dde5e4a210719 100644 > --- a/drivers/usb/host/xhci-pci.c > +++ b/drivers/usb/host/xhci-pci.c > @@ -667,9 +667,7 @@ static void xhci_pci_remove(struct pci_dev *dev) > xhci->shared_hcd = NULL; > } > > - /* Workaround for spurious wakeups at shutdown with HSW */ > - if (xhci->quirks & XHCI_SPURIOUS_WAKEUP) > - pci_set_power_state(dev, PCI_D3hot); > + pci_set_power_state(dev, PCI_D3hot); > > usb_hcd_pci_remove(dev); > } > @@ -882,9 +880,7 @@ static void xhci_pci_shutdown(struct usb_hcd *hcd) > xhci_shutdown(hcd); > xhci_cleanup_msix(xhci); > > - /* Yet another workaround for spurious wakeups at shutdown with HSW */ > - if (xhci->quirks & XHCI_SPURIOUS_WAKEUP) > - pci_set_power_state(pdev, PCI_D3hot); > + pci_set_power_state(pdev, PCI_D3hot); Hi Mario & Mathias, According to xHCI spec v1.2: A.1.2 Power State Definitions: Software shall place each downstream USB port with power enabled into the Suspend or Disabled state before it attempts to move the xHC out of the D0 power state. But I have not found any USB core code does it, do you have any ideas about it? We have added the similar codes at non-PCI USB platform, but met above concerns. In fact, we met kernel dump that the thread usb-storage try to access the port status when the platform xHCI code has already put the controller to D3. Best regards, Peter
On 8/27/2024 01:32, Peter Chen wrote: > On 24-07-12 13:54:18, superm1@kernel.org wrote: >> From: Mario Limonciello <mario.limonciello@amd.com> >> >> A workaround was put in place for Haswell systems with spurious events >> to put XHCI controllers into D3hot at shutdown. This solution actually >> makes sense for all XHCI controllers though because XHCI controllers >> left in D0 by the OS may remain in D0 when the SoC goes into S5. >> >> Explicitly put all XHCI controllers into D3hot at shutdown and when >> module is unloaded. >> >> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com> >> --- >> drivers/usb/host/xhci-pci.c | 8 ++------ >> 1 file changed, 2 insertions(+), 6 deletions(-) >> >> diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c >> index 4408d4caf66d2..dde5e4a210719 100644 >> --- a/drivers/usb/host/xhci-pci.c >> +++ b/drivers/usb/host/xhci-pci.c >> @@ -667,9 +667,7 @@ static void xhci_pci_remove(struct pci_dev *dev) >> xhci->shared_hcd = NULL; >> } >> >> - /* Workaround for spurious wakeups at shutdown with HSW */ >> - if (xhci->quirks & XHCI_SPURIOUS_WAKEUP) >> - pci_set_power_state(dev, PCI_D3hot); >> + pci_set_power_state(dev, PCI_D3hot); >> >> usb_hcd_pci_remove(dev); >> } >> @@ -882,9 +880,7 @@ static void xhci_pci_shutdown(struct usb_hcd *hcd) >> xhci_shutdown(hcd); >> xhci_cleanup_msix(xhci); >> >> - /* Yet another workaround for spurious wakeups at shutdown with HSW */ >> - if (xhci->quirks & XHCI_SPURIOUS_WAKEUP) >> - pci_set_power_state(pdev, PCI_D3hot); >> + pci_set_power_state(pdev, PCI_D3hot); > > Hi Mario & Mathias, > > According to xHCI spec v1.2: A.1.2 Power State Definitions: > > Software shall place each downstream USB port with power > enabled into the Suspend or Disabled state before it > attempts to move the xHC out of the D0 power state. > > But I have not found any USB core code does it, do you have any ideas > about it? > > We have added the similar codes at non-PCI USB platform, but met above > concerns. In fact, we met kernel dump that the thread usb-storage try > to access the port status when the platform xHCI code has already put > the controller to D3. > > Best regards, > Peter > > This is pretty tangential to my patch. But FWIW in case you missed we're going to discard this patch in favor of another approach in PCI core. Regarding your point though If I'm not mistaken this should be handled by the Linux parent/child device model. Each of the ports should be children of the hub they're connected to and the hub a child of the controller. So when doing any actions that start runtime PM on the host controller the children need to first be in runtime PM.
On 24-08-27 13:44:02, Mario Limonciello wrote: > On 8/27/2024 01:32, Peter Chen wrote: > > On 24-07-12 13:54:18, superm1@kernel.org wrote: > > > From: Mario Limonciello <mario.limonciello@amd.com> > > > > > > A workaround was put in place for Haswell systems with spurious events > > > to put XHCI controllers into D3hot at shutdown. This solution actually > > > makes sense for all XHCI controllers though because XHCI controllers > > > left in D0 by the OS may remain in D0 when the SoC goes into S5. > > > > > > Explicitly put all XHCI controllers into D3hot at shutdown and when > > > module is unloaded. > > > > > > Signed-off-by: Mario Limonciello <mario.limonciello@amd.com> > > > --- > > > drivers/usb/host/xhci-pci.c | 8 ++------ > > > 1 file changed, 2 insertions(+), 6 deletions(-) > > > > > > diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c > > > index 4408d4caf66d2..dde5e4a210719 100644 > > > --- a/drivers/usb/host/xhci-pci.c > > > +++ b/drivers/usb/host/xhci-pci.c > > > @@ -667,9 +667,7 @@ static void xhci_pci_remove(struct pci_dev *dev) > > > xhci->shared_hcd = NULL; > > > } > > > - /* Workaround for spurious wakeups at shutdown with HSW */ > > > - if (xhci->quirks & XHCI_SPURIOUS_WAKEUP) > > > - pci_set_power_state(dev, PCI_D3hot); > > > + pci_set_power_state(dev, PCI_D3hot); > > > usb_hcd_pci_remove(dev); > > > } > > > @@ -882,9 +880,7 @@ static void xhci_pci_shutdown(struct usb_hcd *hcd) > > > xhci_shutdown(hcd); > > > xhci_cleanup_msix(xhci); > > > - /* Yet another workaround for spurious wakeups at shutdown with HSW */ > > > - if (xhci->quirks & XHCI_SPURIOUS_WAKEUP) > > > - pci_set_power_state(pdev, PCI_D3hot); > > > + pci_set_power_state(pdev, PCI_D3hot); > > > > Hi Mario & Mathias, > > > > According to xHCI spec v1.2: A.1.2 Power State Definitions: > > > > Software shall place each downstream USB port with power > > enabled into the Suspend or Disabled state before it > > attempts to move the xHC out of the D0 power state. > > > > But I have not found any USB core code does it, do you have any ideas > > about it? > > > > We have added the similar codes at non-PCI USB platform, but met above > > concerns. In fact, we met kernel dump that the thread usb-storage try > > to access the port status when the platform xHCI code has already put > > the controller to D3. > > > > Best regards, > > Peter > > > > > > This is pretty tangential to my patch. But FWIW in case you missed we're > going to discard this patch in favor of another approach in PCI core. > > Regarding your point though If I'm not mistaken this should be handled by > the Linux parent/child device model. Each of the ports should be children > of the hub they're connected to and the hub a child of the controller. So > when doing any actions that start runtime PM on the host controller the > children need to first be in runtime PM. > It seems there is no runtime PM suspend for xhci and USB core at .shutdown currently. Alan & Mathias, please correct me if I was wrong. Thanks, Peter
>>> Hi Mario & Mathias, >>> >>> According to xHCI spec v1.2: A.1.2 Power State Definitions: >>> >>> Software shall place each downstream USB port with power >>> enabled into the Suspend or Disabled state before it >>> attempts to move the xHC out of the D0 power state. >>> >>> But I have not found any USB core code does it, do you have any ideas >>> about it? >>> >>> We have added the similar codes at non-PCI USB platform, but met above >>> concerns. In fact, we met kernel dump that the thread usb-storage try >>> to access the port status when the platform xHCI code has already put >>> the controller to D3. >>> >>> Best regards, >>> Peter >>> >>> >> >> This is pretty tangential to my patch. But FWIW in case you missed we're >> going to discard this patch in favor of another approach in PCI core. >> >> Regarding your point though If I'm not mistaken this should be handled by >> the Linux parent/child device model. Each of the ports should be children >> of the hub they're connected to and the hub a child of the controller. So >> when doing any actions that start runtime PM on the host controller the >> children need to first be in runtime PM. >> > > It seems there is no runtime PM suspend for xhci and USB core at > .shutdown currently. Alan & Mathias, please correct me if I was wrong. > I think you are right. At shutdown we only halt the xHC. We don't force ports to suspend or disable state. We only put some selected xHC to D3 USB 2 ports might suspend themselves if there is no activity. Doesn't seem like usb core hcd code, or hub driver does anything either. Thanks Mathias
On Wed, Aug 28, 2024 at 05:02:10PM +0300, Mathias Nyman wrote: > > > > Hi Mario & Mathias, > > > > > > > > According to xHCI spec v1.2: A.1.2 Power State Definitions: > > > > > > > > Software shall place each downstream USB port with power > > > > enabled into the Suspend or Disabled state before it > > > > attempts to move the xHC out of the D0 power state. > > > > > > > > But I have not found any USB core code does it, do you have any ideas > > > > about it? > > > > > > > > We have added the similar codes at non-PCI USB platform, but met above > > > > concerns. In fact, we met kernel dump that the thread usb-storage try > > > > to access the port status when the platform xHCI code has already put > > > > the controller to D3. > > > > > > > > Best regards, > > > > Peter > > > > > > > > > > > > > > This is pretty tangential to my patch. But FWIW in case you missed we're > > > going to discard this patch in favor of another approach in PCI core. > > > > > > Regarding your point though If I'm not mistaken this should be handled by > > > the Linux parent/child device model. Each of the ports should be children > > > of the hub they're connected to and the hub a child of the controller. So > > > when doing any actions that start runtime PM on the host controller the > > > children need to first be in runtime PM. > > > > > > > It seems there is no runtime PM suspend for xhci and USB core at > > .shutdown currently. Alan & Mathias, please correct me if I was wrong. > > > > I think you are right. At shutdown we only halt the xHC. > We don't force ports to suspend or disable state. > We only put some selected xHC to D3 > > USB 2 ports might suspend themselves if there is no activity. > > Doesn't seem like usb core hcd code, or hub driver does anything either. That's right. Host controller drivers are supposed to handle shutdown operations by themselves. The USB core doesn't do anything. Alan Stern
diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c index 4408d4caf66d2..dde5e4a210719 100644 --- a/drivers/usb/host/xhci-pci.c +++ b/drivers/usb/host/xhci-pci.c @@ -667,9 +667,7 @@ static void xhci_pci_remove(struct pci_dev *dev) xhci->shared_hcd = NULL; } - /* Workaround for spurious wakeups at shutdown with HSW */ - if (xhci->quirks & XHCI_SPURIOUS_WAKEUP) - pci_set_power_state(dev, PCI_D3hot); + pci_set_power_state(dev, PCI_D3hot); usb_hcd_pci_remove(dev); } @@ -882,9 +880,7 @@ static void xhci_pci_shutdown(struct usb_hcd *hcd) xhci_shutdown(hcd); xhci_cleanup_msix(xhci); - /* Yet another workaround for spurious wakeups at shutdown with HSW */ - if (xhci->quirks & XHCI_SPURIOUS_WAKEUP) - pci_set_power_state(pdev, PCI_D3hot); + pci_set_power_state(pdev, PCI_D3hot); } /*-------------------------------------------------------------------------*/