| Message ID | 1405505022-7593-1-git-send-email-vidyas@nvidia.com (mailing list archive) |
|---|---|
| State | New, archived |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
On Wed, Jul 16, 2014 at 03:33:42PM +0530, Vidya Sagar wrote: > From: Vidya Sagar <sagar.tv@gmail.com> > > Commit 1a680b7c3258 ("PCI: PCIe links may not get configured for ASPM > under POWERSAVE mode") moved pcie_aspm_powersave_config_link() out of > pci_raw_set_power_state() to pci_set_power_state() which would enable > ASPM. But, with Commit db288c9c5f9d ("PCI / PM: restore the original > behavior of pci_set_power_state()"), which re-introduced the following check > ./drivers/pci/pci.c: pci_set_power_state() > > + /* Check if we're already there */ > + if (dev->current_state == state) > + return 0; > > in pci_set_power_state(), call to pcie_aspm_powersave_config_link() is never > made leaving ASPM broken. > Fix it by configuring links for ASPM in do_pci_enable_device() instead of > pci_set_power_state() > > Suggested-by: Bjorn Helgaas <bhelgaas@google.com> > Signed-off-by: Vidya Sagar <sagar.tv@gmail.com> I applied this to pci/misc for v3.17 with the following changelog: It would still make me feel better if Matthew and/or Rafael acked this. PCI: Configure ASPM when enabling device We can't do ASPM configuration at enumeration-time because enabling it makes some defective hardware unresponsive, even if ASPM is disabled later (see 41cd766b0659 ("PCI: Don't enable aspm before drivers have had a chance to veto it"). Therefore, we have to do it after a driver claims the device. We previously configured ASPM in pci_set_power_state(), but that's not a very good place because it's not really related to setting the PCI device power state, and doing it there means: - We incorrectly skipped ASPM config when setting a device that's already in D0 to D0. - We unnecessarily configured ASPM when setting a device to a low-power state (the ASPM feature only applies when the device is in D0). - We unnecessarily configured ASPM when called from a .resume() method (ASPM configuration needs to be restored during resume, but I think pci_restore_pcie_state() should already do this). Move ASPM configuration from pci_set_power_state() to do_pci_enable_device() so we do it when a driver enables a device. [bhelgaas: changelog] Link: https://bugzilla.kernel.org/show_bug.cgi?id=79621 It would still make me feel better if Matthew and/or Rafael chimed in to make sure this is sane. Bjorn > --- > v3: > * Modified commit message > removed single quotes around commit messages > added Suggested-by line > > v2: > * Calling ASPM config code is moved from pci_set_power_state() to > * do_pci_enable_device() > > drivers/pci/pci.c | 12 ++++++------ > 1 file changed, 6 insertions(+), 6 deletions(-) > > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > index 1c8592b..81d49d3 100644 > --- a/drivers/pci/pci.c > +++ b/drivers/pci/pci.c > @@ -839,12 +839,6 @@ int pci_set_power_state(struct pci_dev *dev, pci_power_t state) > > if (!__pci_complete_power_transition(dev, state)) > error = 0; > - /* > - * When aspm_policy is "powersave" this call ensures > - * that ASPM is configured. > - */ > - if (!error && dev->bus->self) > - pcie_aspm_powersave_config_link(dev->bus->self); > > return error; > } > @@ -1195,12 +1189,18 @@ int __weak pcibios_enable_device(struct pci_dev *dev, int bars) > static int do_pci_enable_device(struct pci_dev *dev, int bars) > { > int err; > + struct pci_dev *bridge; > u16 cmd; > u8 pin; > > err = pci_set_power_state(dev, PCI_D0); > if (err < 0 && err != -EIO) > return err; > + > + bridge = pci_upstream_bridge(dev); > + if (bridge) > + pcie_aspm_powersave_config_link(bridge); > + > err = pcibios_enable_device(dev, bars); > if (err < 0) > return err; > -- > 1.8.1.5 > -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Thu, Jul 17, 2014 at 1:06 AM, Bjorn Helgaas <bhelgaas@google.com> wrote: > On Wed, Jul 16, 2014 at 03:33:42PM +0530, Vidya Sagar wrote: >> From: Vidya Sagar <sagar.tv@gmail.com> >> >> Commit 1a680b7c3258 ("PCI: PCIe links may not get configured for ASPM >> under POWERSAVE mode") moved pcie_aspm_powersave_config_link() out of >> pci_raw_set_power_state() to pci_set_power_state() which would enable >> ASPM. But, with Commit db288c9c5f9d ("PCI / PM: restore the original >> behavior of pci_set_power_state()"), which re-introduced the following check >> ./drivers/pci/pci.c: pci_set_power_state() >> >> + /* Check if we're already there */ >> + if (dev->current_state == state) >> + return 0; >> >> in pci_set_power_state(), call to pcie_aspm_powersave_config_link() is never >> made leaving ASPM broken. >> Fix it by configuring links for ASPM in do_pci_enable_device() instead of >> pci_set_power_state() >> >> Suggested-by: Bjorn Helgaas <bhelgaas@google.com> >> Signed-off-by: Vidya Sagar <sagar.tv@gmail.com> > > I applied this to pci/misc for v3.17 with the following changelog: Thanks, > > It would still make me feel better if Matthew and/or Rafael acked this. > > PCI: Configure ASPM when enabling device > > We can't do ASPM configuration at enumeration-time because enabling it > makes some defective hardware unresponsive, even if ASPM is disabled later > (see 41cd766b0659 ("PCI: Don't enable aspm before drivers have had a chance > to veto it"). Therefore, we have to do it after a driver claims the > device. > > We previously configured ASPM in pci_set_power_state(), but that's not a > very good place because it's not really related to setting the PCI device > power state, and doing it there means: > > - We incorrectly skipped ASPM config when setting a device that's > already in D0 to D0. > > - We unnecessarily configured ASPM when setting a device to a low-power > state (the ASPM feature only applies when the device is in D0). > > - We unnecessarily configured ASPM when called from a .resume() method > (ASPM configuration needs to be restored during resume, but I think > pci_restore_pcie_state() should already do this). > > Move ASPM configuration from pci_set_power_state() to > do_pci_enable_device() so we do it when a driver enables a device. > > [bhelgaas: changelog] > Link: https://bugzilla.kernel.org/show_bug.cgi?id=79621 > > It would still make me feel better if Matthew and/or Rafael chimed in to > make sure this is sane. > > Bjorn > >> --- >> v3: >> * Modified commit message >> removed single quotes around commit messages >> added Suggested-by line >> >> v2: >> * Calling ASPM config code is moved from pci_set_power_state() to >> * do_pci_enable_device() >> >> drivers/pci/pci.c | 12 ++++++------ >> 1 file changed, 6 insertions(+), 6 deletions(-) >> >> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c >> index 1c8592b..81d49d3 100644 >> --- a/drivers/pci/pci.c >> +++ b/drivers/pci/pci.c >> @@ -839,12 +839,6 @@ int pci_set_power_state(struct pci_dev *dev, pci_power_t state) >> >> if (!__pci_complete_power_transition(dev, state)) >> error = 0; >> - /* >> - * When aspm_policy is "powersave" this call ensures >> - * that ASPM is configured. >> - */ >> - if (!error && dev->bus->self) >> - pcie_aspm_powersave_config_link(dev->bus->self); >> >> return error; >> } >> @@ -1195,12 +1189,18 @@ int __weak pcibios_enable_device(struct pci_dev *dev, int bars) >> static int do_pci_enable_device(struct pci_dev *dev, int bars) >> { >> int err; >> + struct pci_dev *bridge; >> u16 cmd; >> u8 pin; >> >> err = pci_set_power_state(dev, PCI_D0); >> if (err < 0 && err != -EIO) >> return err; >> + >> + bridge = pci_upstream_bridge(dev); >> + if (bridge) >> + pcie_aspm_powersave_config_link(bridge); >> + >> err = pcibios_enable_device(dev, bars); >> if (err < 0) >> return err; >> -- >> 1.8.1.5 >> -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Wednesday, July 16, 2014 01:36:37 PM Bjorn Helgaas wrote: > On Wed, Jul 16, 2014 at 03:33:42PM +0530, Vidya Sagar wrote: > > From: Vidya Sagar <sagar.tv@gmail.com> > > > > Commit 1a680b7c3258 ("PCI: PCIe links may not get configured for ASPM > > under POWERSAVE mode") moved pcie_aspm_powersave_config_link() out of > > pci_raw_set_power_state() to pci_set_power_state() which would enable > > ASPM. But, with Commit db288c9c5f9d ("PCI / PM: restore the original > > behavior of pci_set_power_state()"), which re-introduced the following check > > ./drivers/pci/pci.c: pci_set_power_state() > > > > + /* Check if we're already there */ > > + if (dev->current_state == state) > > + return 0; > > > > in pci_set_power_state(), call to pcie_aspm_powersave_config_link() is never > > made leaving ASPM broken. > > Fix it by configuring links for ASPM in do_pci_enable_device() instead of > > pci_set_power_state() > > > > Suggested-by: Bjorn Helgaas <bhelgaas@google.com> > > Signed-off-by: Vidya Sagar <sagar.tv@gmail.com> > > I applied this to pci/misc for v3.17 with the following changelog: > > It would still make me feel better if Matthew and/or Rafael acked this. > > PCI: Configure ASPM when enabling device > > We can't do ASPM configuration at enumeration-time because enabling it > makes some defective hardware unresponsive, even if ASPM is disabled later > (see 41cd766b0659 ("PCI: Don't enable aspm before drivers have had a chance > to veto it"). Therefore, we have to do it after a driver claims the > device. > > We previously configured ASPM in pci_set_power_state(), but that's not a > very good place because it's not really related to setting the PCI device > power state, and doing it there means: > > - We incorrectly skipped ASPM config when setting a device that's > already in D0 to D0. > > - We unnecessarily configured ASPM when setting a device to a low-power > state (the ASPM feature only applies when the device is in D0). > > - We unnecessarily configured ASPM when called from a .resume() method > (ASPM configuration needs to be restored during resume, but I think > pci_restore_pcie_state() should already do this). > > Move ASPM configuration from pci_set_power_state() to > do_pci_enable_device() so we do it when a driver enables a device. > > [bhelgaas: changelog] > Link: https://bugzilla.kernel.org/show_bug.cgi?id=79621 > > It would still make me feel better if Matthew and/or Rafael chimed in to > make sure this is sane. I like the change, but I'm not sure whether or not it will work for everyone. The only way to verify that seems to be to apply it, however. Rafael -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 1c8592b..81d49d3 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -839,12 +839,6 @@ int pci_set_power_state(struct pci_dev *dev, pci_power_t state) if (!__pci_complete_power_transition(dev, state)) error = 0; - /* - * When aspm_policy is "powersave" this call ensures - * that ASPM is configured. - */ - if (!error && dev->bus->self) - pcie_aspm_powersave_config_link(dev->bus->self); return error; } @@ -1195,12 +1189,18 @@ int __weak pcibios_enable_device(struct pci_dev *dev, int bars) static int do_pci_enable_device(struct pci_dev *dev, int bars) { int err; + struct pci_dev *bridge; u16 cmd; u8 pin; err = pci_set_power_state(dev, PCI_D0); if (err < 0 && err != -EIO) return err; + + bridge = pci_upstream_bridge(dev); + if (bridge) + pcie_aspm_powersave_config_link(bridge); + err = pcibios_enable_device(dev, bars); if (err < 0) return err;