usbdebug: Force EHCI to D0 state
When resuming from ACPI S3 suspend, EHCI controller
may be in D3 power-management state. Bring it to D0
early so it is functional for console.
NOTE: D3hot->D0 transition was observed to reset
previous programming of PCI_COMMAND register.
Change-Id: Id177ce61926beb057fe67ba42a306d8e565d2657
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/20827
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Patrick Rudolph <siro@das-labor.org>
diff --git a/src/drivers/usb/pci_ehci.c b/src/drivers/usb/pci_ehci.c
index 9099976..73c709c 100644
--- a/src/drivers/usb/pci_ehci.c
+++ b/src/drivers/usb/pci_ehci.c
@@ -44,6 +44,15 @@
if (class != PCI_EHCI_CLASSCODE)
return -1;
+ u8 pm_cap = pci_find_capability(dev, PCI_CAP_ID_PM);
+ if (pm_cap) {
+ u16 pm_ctrl = pci_read_config16(dev, pm_cap + PCI_PM_CTRL);
+ /* Set to D0 and disable PM events. */
+ pm_ctrl &= ~PCI_PM_CTRL_PME_ENABLE;
+ pm_ctrl &= ~PCI_PM_CTRL_STATE_MASK;
+ pci_write_config16(dev, pm_cap + PCI_PM_CTRL, pm_ctrl);
+ }
+
u8 pos = pci_find_capability(dev, PCI_CAP_ID_EHCI_DEBUG);
if (!pos)
return -1;