ACPI: bus: Rework the handling of \_SB._OSC USB4 features

Use acpi_osc_handshake() introduced previously for implementing the
\_SB._OSC USB4 features control negotiation.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Link: https://patch.msgid.link/3879947.MHq7AAxBmi@rafael.j.wysocki

diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
index 3a6ce53aef4744739d1173e6b9a4be699495f2bf..d0cb47c7744616c126b3cb02631fa1ebe1b7f39d 100644 (file)
--- a/drivers/acpi/bus.c
+++ b/drivers/acpi/bus.c
@@ -528,19 +528,15 @@ static void acpi_bus_decode_usb_osc(const char *msg, u32 bits)
               (bits & OSC_USB_XDOMAIN) ? '+' : '-');
 }
 
-static u8 sb_usb_uuid_str[] = "23A0D13A-26AB-486C-9C5F-0FFA525A575A";
 static void acpi_bus_osc_negotiate_usb_control(void)
 {
-       u32 capbuf[3], *capbuf_ret;
-       struct acpi_osc_context context = {
-               .uuid_str = sb_usb_uuid_str,
-               .rev = 1,
-               .cap.length = sizeof(capbuf),
-               .cap.pointer = capbuf,
+       static const u8 sb_usb_uuid_str[] = "23A0D13A-26AB-486C-9C5F-0FFA525A575A";
+       u32 capbuf[3], control;
+       struct acpi_buffer cap = {
+               .pointer = capbuf,
+               .length = sizeof(capbuf),
        };
        acpi_handle handle;
-       acpi_status status;
-       u32 control;
 
        if (!osc_sb_native_usb4_support_confirmed)
                return;
@@ -551,54 +547,16 @@ 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;
 
-       /*
-        * 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;
 
-       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;
-       }
-
-       /*
-        * 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))
+       if (acpi_osc_handshake(handle, sb_usb_uuid_str, 1, &cap))
                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);
+       osc_sb_native_usb4_control = capbuf[OSC_CONTROL_DWORD];
 
        acpi_bus_decode_usb_osc("USB4 _OSC: OS supports", control);
-       acpi_bus_decode_usb_osc("USB4 _OSC: OS controls",
-                               osc_sb_native_usb4_control);
-
-out_free:
-       kfree(context.ret.pointer);
+       acpi_bus_decode_usb_osc("USB4 _OSC: OS controls", osc_sb_native_usb4_control);
 }
 
 /* --------------------------------------------------------------------------