Enable LTR(Latency tolerance reporting) and OBFF(optimized buffer flush/fill) in
pci_enable_device(), so that they are enabled before the device is used by driver.
Signed-off-by: Xudong Hao <xudong.hao@xxxxxxxxx>
---
drivers/pci/pci.c | 29 +++++++++++++++++++++++++++++
1 files changed, 29 insertions(+), 0 deletions(-)
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 111569c..2369883 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -1134,6 +1134,31 @@ int pci_load_and_free_saved_state(struct pci_dev *dev,
}
EXPORT_SYMBOL_GPL(pci_load_and_free_saved_state);
+static void pci_enable_dev_caps(struct pci_dev *dev)
+{
+ /* set default value */
+ unsigned long type = PCI_EXP_OBFF_SIGNAL_ALWAYS;
+
+ /* LTR(Latency tolerance reporting) allows devices to send
+ * messages to the root complex indicating their latency
+ * tolerance for snooped & unsnooped memory transactions.
+ */
+ pci_enable_ltr(dev);
+
+ /* OBFF (optimized buffer flush/fill), where supported,
+ * can help improve energy efficiency by giving devices
+ * information about when interrupts and other activity
+ * will have a reduced power impact.
+ */
+ pci_enable_obff(dev, type);
+}
+
+static void pci_disable_dev_caps(struct pci_dev *dev)
+{
+ pci_disable_obff(dev);
+ pci_disable_ltr(dev);
+}
+
static int do_pci_enable_device(struct pci_dev *dev, int bars)
{
int err;
@@ -1146,6 +1171,9 @@ static int do_pci_enable_device(struct pci_dev *dev, int bars)
return err;
pci_fixup_device(pci_fixup_enable, dev);
+ /* Enable some device capibility before it's used by driver. */
+ pci_enable_dev_caps(dev);
+
return 0;
}
@@ -1361,6 +1389,7 @@ static void do_pci_disable_device(struct pci_dev *dev)
}
pcibios_disable_device(dev);
+ pci_disable_dev_caps(dev);
}
/**
--
1.6.0.rc1
--
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