Fix failure to load power HAL implementation

Some working implementations of the libhardware power HAL do not
implement an open method. Change the HIDL implementation to not rely
on that method being available.

Test: Flashed marlin with modified power.marlin that omits an open()
implementation; power HAL loads successfully and passes VTS
Bug: 37245218
Signed-off-by: Connor O'Brien <connoro@google.com>
Change-Id: Icc77b3011a0e44330062aa51ae49e39ad349a2a5

diff --git a/power/1.0/default/Power.cpp b/power/1.0/default/Power.cpp
index 6ea9167..51f87f5 100644 (file)
--- a/power/1.0/default/Power.cpp
+++ b/power/1.0/default/Power.cpp
@@ -145,25 +145,27 @@ done:
 }
 
 IPower* HIDL_FETCH_IPower(const char* /* name */) {
-    int ret = 0;
-    const hw_module_t* hw_module = NULL;
-    power_module_t *power_module;
-    ret = hw_get_module(POWER_HARDWARE_MODULE_ID, &hw_module);
-    if (ret == 0 && hw_module->methods->open) {
-        ret = hw_module->methods->open(hw_module, POWER_HARDWARE_MODULE_ID,
-                reinterpret_cast<hw_device_t**>(&power_module));
-        if (ret == 0) {
-            return new Power(power_module);
-        }
-        else {
-            ALOGE("Passthrough failed to load legacy power HAL.");
+    const hw_module_t* hw_module = nullptr;
+    power_module_t* power_module = nullptr;
+    int err = hw_get_module(POWER_HARDWARE_MODULE_ID, &hw_module);
+    if (err) {
+        ALOGE("hw_get_module %s failed: %d", POWER_HARDWARE_MODULE_ID, err);
+        return nullptr;
+    }
+
+    if (!hw_module->methods || !hw_module->methods->open) {
+        power_module = reinterpret_cast<power_module_t*>(
+            const_cast<hw_module_t*>(hw_module));
+    } else {
+        err = hw_module->methods->open(
+            hw_module, POWER_HARDWARE_MODULE_ID,
+            reinterpret_cast<hw_device_t**>(&power_module));
+        if (err) {
+            ALOGE("Passthrough failed to load legacy HAL.");
             return nullptr;
         }
     }
-    else {
-        ALOGE ("hw_get_module %s failed: %d", POWER_HARDWARE_MODULE_ID, ret);
-        return nullptr;
-    }
+    return new Power(power_module);
 }
 
 } // namespace implementation