Commit 84ddfda6 authored by Ben Skeggs's avatar Ben Skeggs
Browse files

drm/nouveau/mxm: call mxmi to determine revision before calling mxms

There's a HP laptop out there where the MXM version in the VBIOS doesn't
match what the ACPI implementation is expecting.  These tables will accept
0x00 to MXMS to return latest version, but *only* if MXMI has been called
Signed-off-by: default avatarBen Skeggs <>
parent 7d3a766b
......@@ -582,6 +582,35 @@ mxm_shadow_dsm(struct drm_device *dev, u8 version)
#define WMI_WMMX_GUID "F6CB5C3C-9CAE-4EBD-B577-931EA32A2CC0"
static u8
wmi_wmmx_mxmi(struct drm_device *dev, u8 version)
u32 mxmi_args[] = { 0x494D584D /* MXMI */, version, 0 };
struct acpi_buffer args = { sizeof(mxmi_args), mxmi_args };
struct acpi_buffer retn = { ACPI_ALLOCATE_BUFFER, NULL };
union acpi_object *obj;
acpi_status status;
status = wmi_evaluate_method(WMI_WMMX_GUID, 0, 0, &args, &retn);
if (ACPI_FAILURE(status)) {
MXM_DBG(dev, "WMMX MXMI returned %d\n", status);
return 0x00;
obj = retn.pointer;
if (obj->type == ACPI_TYPE_INTEGER) {
version = obj->integer.value;
MXM_DBG(dev, "WMMX MXMI version %d.%d\n",
(version >> 4), version & 0x0f);
} else {
version = 0;
MXM_DBG(dev, "WMMX MXMI returned non-integer\n");
return version;
static bool
mxm_shadow_wmi(struct drm_device *dev, u8 version)
......@@ -592,7 +621,15 @@ mxm_shadow_wmi(struct drm_device *dev, u8 version)
union acpi_object *obj;
acpi_status status;
if (!wmi_has_guid(WMI_WMMX_GUID))
if (!wmi_has_guid(WMI_WMMX_GUID)) {
MXM_DBG(dev, "WMMX GUID not found\n");
return false;
mxms_args[1] = wmi_wmmx_mxmi(dev, 0x00);
if (!mxms_args[1])
mxms_args[1] = wmi_wmmx_mxmi(dev, version);
if (!mxms_args[1])
return false;
status = wmi_evaluate_method(WMI_WMMX_GUID, 0, 0, &args, &retn);
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