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path: root/drivers/pci/pci.c
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Diffstat (limited to 'drivers/pci/pci.c')
-rw-r--r--drivers/pci/pci.c59
1 files changed, 55 insertions, 4 deletions
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 1b34fc56067..65ea7d25f69 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -222,6 +222,37 @@ pci_find_parent_resource(const struct pci_dev *dev, struct resource *res)
}
/**
+ * pci_restore_bars - restore a devices BAR values (e.g. after wake-up)
+ * @dev: PCI device to have its BARs restored
+ *
+ * Restore the BAR values for a given device, so as to make it
+ * accessible by its driver.
+ */
+void
+pci_restore_bars(struct pci_dev *dev)
+{
+ int i, numres;
+
+ switch (dev->hdr_type) {
+ case PCI_HEADER_TYPE_NORMAL:
+ numres = 6;
+ break;
+ case PCI_HEADER_TYPE_BRIDGE:
+ numres = 2;
+ break;
+ case PCI_HEADER_TYPE_CARDBUS:
+ numres = 1;
+ break;
+ default:
+ /* Should never get here, but just in case... */
+ return;
+ }
+
+ for (i = 0; i < numres; i ++)
+ pci_update_resource(dev, &dev->resource[i], i);
+}
+
+/**
* pci_set_power_state - Set the power state of a PCI device
* @dev: PCI device to be suspended
* @state: PCI power state (D0, D1, D2, D3hot, D3cold) we're entering
@@ -239,7 +270,7 @@ int (*platform_pci_set_power_state)(struct pci_dev *dev, pci_power_t t);
int
pci_set_power_state(struct pci_dev *dev, pci_power_t state)
{
- int pm;
+ int pm, need_restore = 0;
u16 pmcsr, pmc;
/* bound the state we're entering */
@@ -278,14 +309,17 @@ pci_set_power_state(struct pci_dev *dev, pci_power_t state)
return -EIO;
}
+ pci_read_config_word(dev, pm + PCI_PM_CTRL, &pmcsr);
+
/* If we're in D3, force entire word to 0.
* This doesn't affect PME_Status, disables PME_En, and
* sets PowerState to 0.
*/
- if (dev->current_state >= PCI_D3hot)
+ if (dev->current_state >= PCI_D3hot) {
+ if (!(pmcsr & PCI_PM_CTRL_NO_SOFT_RESET))
+ need_restore = 1;
pmcsr = 0;
- else {
- pci_read_config_word(dev, pm + PCI_PM_CTRL, &pmcsr);
+ } else {
pmcsr &= ~PCI_PM_CTRL_STATE_MASK;
pmcsr |= state;
}
@@ -308,6 +342,22 @@ pci_set_power_state(struct pci_dev *dev, pci_power_t state)
platform_pci_set_power_state(dev, state);
dev->current_state = state;
+
+ /* According to section 5.4.1 of the "PCI BUS POWER MANAGEMENT
+ * INTERFACE SPECIFICATION, REV. 1.2", a device transitioning
+ * from D3hot to D0 _may_ perform an internal reset, thereby
+ * going to "D0 Uninitialized" rather than "D0 Initialized".
+ * For example, at least some versions of the 3c905B and the
+ * 3c556B exhibit this behaviour.
+ *
+ * At least some laptop BIOSen (e.g. the Thinkpad T21) leave
+ * devices in a D3hot state at boot. Consequently, we need to
+ * restore at least the BARs so that the device will be
+ * accessible to its driver.
+ */
+ if (need_restore)
+ pci_restore_bars(dev);
+
return 0;
}
@@ -805,6 +855,7 @@ struct pci_dev *isa_bridge;
EXPORT_SYMBOL(isa_bridge);
#endif
+EXPORT_SYMBOL_GPL(pci_restore_bars);
EXPORT_SYMBOL(pci_enable_device_bars);
EXPORT_SYMBOL(pci_enable_device);
EXPORT_SYMBOL(pci_disable_device);