diff options
| author | Vidya Sagar <sagar.tv@gmail.com> | 2014-07-16 15:33:42 +0530 |
|---|---|---|
| committer | Jiri Slaby <jslaby@suse.cz> | 2014-09-03 21:31:30 +0200 |
| commit | b7be971e466034b42a972094293c90efb931a989 (patch) | |
| tree | 87e4ab01b66c509f2b8e733b248ecacce0eed87e /drivers/pci | |
| parent | 0d99de503fc0227467bcf18b3660b455e854a51c (diff) | |
| download | lwn-b7be971e466034b42a972094293c90efb931a989.tar.gz lwn-b7be971e466034b42a972094293c90efb931a989.zip | |
PCI: Configure ASPM when enabling device
commit 1f6ae47ecff7f23da73417e068018b311f3b5583 upstream.
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
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
Fixes: db288c9c5f9d ("PCI / PM: restore the original behavior of pci_set_power_state()")
Suggested-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Vidya Sagar <sagar.tv@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Diffstat (limited to 'drivers/pci')
| -rw-r--r-- | drivers/pci/pci.c | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 4108166ffdf4..2d163544fa51 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -782,12 +782,6 @@ 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; } @@ -1120,12 +1114,18 @@ EXPORT_SYMBOL_GPL(pci_load_and_free_saved_state); 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; |