Re: [PATCH v6 1/2] PCI: Add a helper to check Power Resource Requirements _PR3 existence

From: Takashi Iwai <tiwai@suse.de>
To: Kai-Heng Feng <kai.heng.feng@canonical.com>
Cc: bhelgaas@google.com, linux-pci@vger.kernel.org,
	alsa-devel@alsa-project.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v6 1/2] PCI: Add a helper to check Power Resource Requirements _PR3 existence
Date: Fri, 18 Oct 2019 10:45:43 +0200	[thread overview]
Message-ID: <s5hlftih26g.wl-tiwai@suse.de> (raw)
In-Reply-To: <4C18DF4A-FAE8-4762-AF65-F892A4845297@canonical.com>

On Fri, 18 Oct 2019 10:30:11 +0200,
Kai-Heng Feng wrote:
> 
> 
> 
> > On Oct 18, 2019, at 16:18, Takashi Iwai <tiwai@suse.de> wrote:
> > 
> > On Fri, 18 Oct 2019 09:38:47 +0200,
> > Kai-Heng Feng wrote:
> >> 
> >> A driver may want to know the existence of _PR3, to choose different
> >> runtime suspend behavior. A user will be add in next patch.
> >> 
> >> This is mostly the same as nouveau_pr3_present().
> >> 
> >> Reported-by: kbuild test robot <lkp@intel.com>
> > 
> > It's confusing -- this particular change isn't reported by the test
> > bot, but only about the lack of the CONFIG_ACPI ifdef.
> 
> Hmm, because the test bot asked to add the tag.

Yes, but it's only if you add a new fix patch on top of it.
You can write some their credit, too, but basically it'd be enough to
point to the Link tag to the thread.

> If it's not appropriate will you drop it? I can also send a v7.

I can modify in my side.

thanks,

Takashi

> 
> Kai-Heng
> 
> > 
> > 
> > thanks,
> > 
> > Takashi
> > 
> >> Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
> >> ---
> >> v6:
> >> - Only define the function when CONFIG_ACPI is set.
> >> v5:
> >> - Add wording suggestion from Bjorn.
> >> v4:
> >> - Let caller to find its upstream port device.
> >> 
> >> drivers/pci/pci.c   | 18 ++++++++++++++++++
> >> include/linux/pci.h |  2 ++
> >> 2 files changed, 20 insertions(+)
> >> 
> >> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> >> index e7982af9a5d8..1df99d9e350e 100644
> >> --- a/drivers/pci/pci.c
> >> +++ b/drivers/pci/pci.c
> >> @@ -5856,6 +5856,24 @@ int pci_set_vga_state(struct pci_dev *dev, bool decode,
> >> 	return 0;
> >> }
> >> 
> >> +#ifdef CONFIG_ACPI
> >> +bool pci_pr3_present(struct pci_dev *pdev)
> >> +{
> >> +	struct acpi_device *adev;
> >> +
> >> +	if (acpi_disabled)
> >> +		return false;
> >> +
> >> +	adev = ACPI_COMPANION(&pdev->dev);
> >> +	if (!adev)
> >> +		return false;
> >> +
> >> +	return adev->power.flags.power_resources &&
> >> +		acpi_has_method(adev->handle, "_PR3");
> >> +}
> >> +EXPORT_SYMBOL_GPL(pci_pr3_present);
> >> +#endif
> >> +
> >> /**
> >>  * pci_add_dma_alias - Add a DMA devfn alias for a device
> >>  * @dev: the PCI device for which alias is added
> >> diff --git a/include/linux/pci.h b/include/linux/pci.h
> >> index f9088c89a534..1d15c5d49cdd 100644
> >> --- a/include/linux/pci.h
> >> +++ b/include/linux/pci.h
> >> @@ -2310,9 +2310,11 @@ struct irq_domain *pci_host_bridge_acpi_msi_domain(struct pci_bus *bus);
> >> 
> >> void
> >> pci_msi_register_fwnode_provider(struct fwnode_handle *(*fn)(struct device *));
> >> +bool pci_pr3_present(struct pci_dev *pdev);
> >> #else
> >> static inline struct irq_domain *
> >> pci_host_bridge_acpi_msi_domain(struct pci_bus *bus) { return NULL; }
> >> +static bool pci_pr3_present(struct pci_dev *pdev) { return false; }
> >> #endif
> >> 
> >> #ifdef CONFIG_EEH
> >> -- 
> >> 2.17.1
> >> 
> 