From 27afb47f6468549600077c5d0331153a4f8c4fee Mon Sep 17 00:00:00 2001
From: Connor O'Brien <connoro@google.com>
Date: Tue, 11 Apr 2017 15:33:04 -0700
Subject: [PATCH] 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
---
 power/1.0/default/Power.cpp | 34 ++++++++++++++++++----------------
 1 file changed, 18 insertions(+), 16 deletions(-)

diff --git a/power/1.0/default/Power.cpp b/power/1.0/default/Power.cpp
index 6ea91673fd..51f87f52f5 100644
--- 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