From: Kai-Heng Feng <kai.heng.feng@canonical.com>
To: bhelgaas@google.com, tiwai@suse.com
Cc: linux-pci@vger.kernel.org, alsa-devel@alsa-project.org,
linux-kernel@vger.kernel.org,
Kai-Heng Feng <kai.heng.feng@canonical.com>
Subject: [PATCH 1/2] PCI: Add a helper to check Power Resource Requirements _PR3 existence
Date: Tue, 27 Aug 2019 21:47:55 +0800 [thread overview]
Message-ID: <20190827134756.10807-1-kai.heng.feng@canonical.com> (raw)
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().
Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
---
drivers/pci/pci.c | 20 ++++++++++++++++++++
include/linux/pci.h | 2 ++
2 files changed, 22 insertions(+)
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 1b27b5af3d55..776af15b92c2 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -5856,6 +5856,26 @@ int pci_set_vga_state(struct pci_dev *dev, bool decode,
return 0;
}
+bool pci_pr3_present(struct pci_dev *pdev)
+{
+ struct pci_dev *parent_pdev = pci_upstream_bridge(pdev);
+ struct acpi_device *parent_adev;
+
+ if (acpi_disabled)
+ return false;
+
+ if (!parent_pdev)
+ return false;
+
+ parent_adev = ACPI_COMPANION(&parent_pdev->dev);
+ if (!parent_adev)
+ return false;
+
+ return parent_adev->power.flags.power_resources &&
+ acpi_has_method(parent_adev->handle, "_PR3");
+}
+EXPORT_SYMBOL_GPL(pci_pr3_present);
+
/**
* 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 82e4cd1b7ac3..9b6f7b67fac9 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -2348,9 +2348,11 @@ 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
next reply other threads:[~2019-08-27 13:48 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-27 13:47 Kai-Heng Feng [this message]
2019-08-27 13:47 ` [PATCH 2/2] ALSA: hda: Allow HDA to be runtime suspended when dGPU is not bound Kai-Heng Feng
2019-08-27 14:50 ` Kai-Heng Feng
2019-08-27 15:24 ` Takashi Iwai
2019-08-27 22:31 ` Bjorn Helgaas
2019-08-28 8:25 ` Kai-Heng Feng
2019-08-28 18:01 ` [PATCH v2 " Kai-Heng Feng
2019-09-05 21:35 ` Bjorn Helgaas
2019-09-17 9:36 ` Kai-Heng Feng
2019-09-18 12:42 ` [PATCH v3 2/2] ALSA: hda: Allow HDA to be runtime suspended when dGPU is not bound to a driver Kai-Heng Feng
2019-08-27 15:25 ` [PATCH 1/2] PCI: Add a helper to check Power Resource Requirements _PR3 existence Takashi Iwai
2019-08-27 16:58 ` Kai-Heng Feng
2019-08-27 22:13 ` Bjorn Helgaas
2019-08-27 22:39 ` Peter Wu
2019-09-09 11:41 ` Bjorn Helgaas
2019-09-20 11:23 ` Kai-Heng Feng
2019-09-20 13:26 ` Bjorn Helgaas
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