Re: [PATCH 5/5] PCI / PM: Decode D3cold power state correctly

Rafael J. Wysocki
2019-08-05T21:14:49Z

On Mon, Aug 5, 2019 at 10:52 PM Bjorn Helgaas <helgaas@kernel.org> wrote:
>
> From: Bjorn Helgaas <bhelgaas@google.com>
>
> Use pci_power_name() to print pci_power_t correctly. This changes:
>
> "state 0" or "D0" to "D0"
> "state 1" or "D1" to "D1"
> "state 2" or "D2" to "D2"
> "state 3" or "D3" to "D3hot"
> "state 4" or "D4" to "D3cold"
>
> Changes dmesg logging only, no other functional change intended.
>
> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

> ---
> drivers/pci/pci.c | 16 +++++++++-------
> 1 file changed, 9 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> index d8686e3cd5eb..17ae2615ac11 100644
> --- a/drivers/pci/pci.c
> +++ b/drivers/pci/pci.c
> @@ -834,14 +834,16 @@ static int pci_raw_set_power_state(struct pci_dev *dev, pci_power_t state)
> return -EINVAL;
>
> /*
> - * Validate current state:
> - * Can enter D0 from any state, but if we can only go deeper
> - * to sleep if we're already in a low power state
> + * Validate transition: We can enter D0 from any state, but if
> + * we're already in a low-power state, we can only go deeper. E.g.,
> + * we can go from D1 to D3, but we can't go directly from D3 to D1;
> + * we'd have to go from D3 to D0, then to D1.
> */
> if (state != PCI_D0 && dev->current_state <= PCI_D3cold
> && dev->current_state > state) {
> - pci_err(dev, "invalid power transition (from state %d to %d)\n",
> - dev->current_state, state);
> + pci_err(dev, "invalid power transition (from %s to %s)\n",
> + pci_power_name(dev->current_state),
> + pci_power_name(state));
> return -EINVAL;
> }
>
> @@ -896,8 +898,8 @@ static int pci_raw_set_power_state(struct pci_dev *dev, pci_power_t state)
> pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
> dev->current_state = pci_power_state(pmcsr);
> if (dev->current_state != state && printk_ratelimit())
> - pci_info(dev, "Refused to change power state, currently in D%d\n",
> - dev->current_state);
> + pci_info(dev, "refused to change power state (currently %s)\n",
> + pci_power_name(dev->current_state));
>
> /*
> * According to section 5.4.1 of the "PCI BUS POWER MANAGEMENT
> --
> 2.22.0.770.g0f2c4a37fd-goog
>