| Message ID | 1405317877-15060-1-git-send-email-vidyas@nvidia.com (mailing list archive) |
|---|---|
| State | New, archived |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
[+cc Matthew, Rafael] On Mon, Jul 14, 2014 at 12:04 AM, Vidya Sagar <sagar.tv@gmail.com> 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 not returning from when the above condition is true, rather, jump to > ASPM configuration code and exit from there eventually. > > Signed-off-by: Vidya Sagar <sagar.tv@gmail.com> I'm OK with the patch (obviously, since I wrote it), but you neglected to copy Matthew and Rafael. And you forgot to rewrite the changelog. I'll take care of the changelog, but I would like to see something from Matthew and Rafael, since this is a significant change in how we configure ASPM. Matthew, Rafael, my observation was: "But I wonder if we can untangle ASPM from pci_set_power_state(). I don't think they're really related. There are a zillion .suspend() and .resume() methods that call pci_set_power_state(). I doubt that we need to do ASPM configuration during suspend, and I'm dubious about resume, too." So the new patch moves the pcie_aspm_powersave_config_link() call out of pci_set_power_state() and into do_pci_enable_device(). Bjorn > --- > 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 Mon, Jul 14, 2014 at 11:34:37AM +0530, Vidya Sagar wrote: > From: Vidya Sagar <sagar.tv@gmail.com> The commit message looks somewhat cluttered: > 'commit 1a680b7c3258 ("PCI: PCIe links may not get configured for ASPM > under POWERSAVE mode")' Usually you'd cite a commit without the extra single quotes. More like this: Commit 1a680b7c3258 ("PCI: PCIe links may not get configured for ASPM under POWERSAVE mode") moved... > 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()")', Same here. > 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; To make this stand out better, it could be preceded and followed by a single blank line (and perhaps indented using tabs). > in pci_set_power_state(), call to pcie_aspm_powersave_config_link() is never > made leaving ASPM broken. > Fix it by not returning from when the above condition is true, rather, jump to > ASPM configuration code and exit from there eventually. > > Signed-off-by: Vidya Sagar <sagar.tv@gmail.com> This patch uses code suggested by Bjorn and it's customary to credit the original author using something like: Suggested-by: Bjorn Helgaas <bhelgaas@google.com> or Originally-by: Bjorn Helgaas <bhelgaas@google.com> Thierry
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;