4.8-stable review patch. If anyone has any objections, please let me know.
------------------ From: Peter Wu <[email protected]> commit b0a6af8b34c9ad20894aa46f85f4bf59d444f286 upstream. Check whether the kernel really supports power resources for a device, otherwise the power might not be removed when the device is runtime suspended (DSM should still work in these cases where PR does not). This is a workaround for a problem where ACPICA and Windows 10 differ in behavior. ACPICA does not correctly enumerate power resources within a conditional block (due to delayed execution of such blocks) and as a result power_resources is set to false even if _PR3 exists. Fixes: 692a17dcc292 ("drm/nouveau/acpi: fix lockup with PCIe runtime PM") Link: https://bugs.freedesktop.org/show_bug.cgi?id=98398 Reported-and-tested-by: Rick Kerkhof <[email protected]> Reviewed-by: Mika Westerberg <[email protected]> Signed-off-by: Peter Wu <[email protected]> Signed-off-by: Dave Airlie <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- drivers/gpu/drm/nouveau/nouveau_acpi.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/drivers/gpu/drm/nouveau/nouveau_acpi.c +++ b/drivers/gpu/drm/nouveau/nouveau_acpi.c @@ -240,7 +240,8 @@ static bool nouveau_pr3_present(struct p if (!parent_adev) return false; - return acpi_has_method(parent_adev->handle, "_PR3"); + return parent_adev->power.flags.power_resources && + acpi_has_method(parent_adev->handle, "_PR3"); } static void nouveau_dsm_pci_probe(struct pci_dev *pdev, acpi_handle *dhandle_out,
