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path: root/drivers/acpi/bus.c
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Diffstat (limited to 'drivers/acpi/bus.c')
-rw-r--r--drivers/acpi/bus.c32
1 files changed, 29 insertions, 3 deletions
diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
index 72e64c0718c9..569bd15f211b 100644
--- a/drivers/acpi/bus.c
+++ b/drivers/acpi/bus.c
@@ -408,7 +408,7 @@ static void acpi_bus_decode_usb_osc(const char *msg, u32 bits)
static u8 sb_usb_uuid_str[] = "23A0D13A-26AB-486C-9C5F-0FFA525A575A";
static void acpi_bus_osc_negotiate_usb_control(void)
{
- u32 capbuf[3];
+ u32 capbuf[3], *capbuf_ret;
struct acpi_osc_context context = {
.uuid_str = sb_usb_uuid_str,
.rev = 1,
@@ -428,7 +428,12 @@ static void acpi_bus_osc_negotiate_usb_control(void)
control = OSC_USB_USB3_TUNNELING | OSC_USB_DP_TUNNELING |
OSC_USB_PCIE_TUNNELING | OSC_USB_XDOMAIN;
- capbuf[OSC_QUERY_DWORD] = 0;
+ /*
+ * Run _OSC first with query bit set, trying to get control over
+ * all tunneling. The platform can then clear out bits in the
+ * control dword that it does not want to grant to the OS.
+ */
+ capbuf[OSC_QUERY_DWORD] = OSC_QUERY_ENABLE;
capbuf[OSC_SUPPORT_DWORD] = 0;
capbuf[OSC_CONTROL_DWORD] = control;
@@ -441,8 +446,29 @@ static void acpi_bus_osc_negotiate_usb_control(void)
goto out_free;
}
+ /*
+ * Run _OSC again now with query bit clear and the control dword
+ * matching what the platform granted (which may not have all
+ * the control bits set).
+ */
+ capbuf_ret = context.ret.pointer;
+
+ capbuf[OSC_QUERY_DWORD] = 0;
+ capbuf[OSC_CONTROL_DWORD] = capbuf_ret[OSC_CONTROL_DWORD];
+
+ kfree(context.ret.pointer);
+
+ status = acpi_run_osc(handle, &context);
+ if (ACPI_FAILURE(status))
+ return;
+
+ if (context.ret.length != sizeof(capbuf)) {
+ pr_info("USB4 _OSC: returned invalid length buffer\n");
+ goto out_free;
+ }
+
osc_sb_native_usb4_control =
- control & acpi_osc_ctx_get_pci_control(&context);
+ control & acpi_osc_ctx_get_pci_control(&context);
acpi_bus_decode_usb_osc("USB4 _OSC: OS supports", control);
acpi_bus_decode_usb_osc("USB4 _OSC: OS controls",