drm/i915: Free the returned object of acpi_evaluate_dsm()

As per the comment on top of acpi_evaluate_dsm():

| * Evaluate device's _DSM method with specified GUID, revision id and
| * function number. Caller needs to free the returned object.

We should free the returned object of acpi_evaluate_dsm() to avoid memory
leakage. Otherwise the kmemleak splat will be triggered at boot time (if we
compile kernel with CONFIG_DEBUG_TEST_DRIVER_REMOVE=y).

Fixes: 8e55f99c510f ("drm/i915: Invoke another _DSM to enable MUX on HP Workstation laptops")
Cc: Kai-Heng Feng <kai.heng.feng@canonical.com>
Signed-off-by: Zenghui Yu <yuzenghui@huawei.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210906033541.862-1-yuzenghui@huawei.com

diff --git a/drivers/gpu/drm/i915/display/intel_acpi.c b/drivers/gpu/drm/i915/display/intel_acpi.c
index 72cac55c0f0f5892bf8369702f3203553363a76a..e78430001f077af531d26d4f8b35d77d715e49f0 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_acpi.c
+++ b/drivers/gpu/drm/i915/display/intel_acpi.c
@@ -186,13 +186,16 @@ void intel_dsm_get_bios_data_funcs_supported(struct drm_i915_private *i915)
 {
        struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
        acpi_handle dhandle;
+       union acpi_object *obj;
 
        dhandle = ACPI_HANDLE(&pdev->dev);
        if (!dhandle)
                return;
 
-       acpi_evaluate_dsm(dhandle, &intel_dsm_guid2, INTEL_DSM_REVISION_ID,
-                         INTEL_DSM_FN_GET_BIOS_DATA_FUNCS_SUPPORTED, NULL);
+       obj = acpi_evaluate_dsm(dhandle, &intel_dsm_guid2, INTEL_DSM_REVISION_ID,
+                               INTEL_DSM_FN_GET_BIOS_DATA_FUNCS_SUPPORTED, NULL);
+       if (obj)
+               ACPI_FREE(obj);
 }
 
 /*