From: Vidya Sagar <[email protected]>
'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 <[email protected]>
---
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
[+cc Matthew, Rafael]
On Mon, Jul 14, 2014 at 12:04 AM, Vidya Sagar <[email protected]> wrote:
> From: Vidya Sagar <[email protected]>
>
> '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 <[email protected]>
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
>
On Mon, Jul 14, 2014 at 11:34:37AM +0530, Vidya Sagar wrote:
> From: Vidya Sagar <[email protected]>
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 <[email protected]>
This patch uses code suggested by Bjorn and it's customary to credit the
original author using something like:
Suggested-by: Bjorn Helgaas <[email protected]>
or
Originally-by: Bjorn Helgaas <[email protected]>
Thierry