commit 16e8ed254d11c3a4dd5360e0bebb5b376a3809f8
author Chia-I Wu <olv@google.com> Thu Oct 19 09:49:03 2017 -0700
committer Chia-I Wu <olv@google.com> Mon Nov 06 15:08:07 2017 -0800
tree a0e395afa12accfbe439f7d0ff31cf45b67eade8
parent 8101b24ca7415c1ddc52b0ce0a0e6b6a4d7eb06a

graphics: support FB HAL using HWC2OnFbAdapter

FB (framebuffer) HAL has been replaced by HWC HAL for 5+ years, but
we still support the legacy path in SurfaceFlinger.  Devices using
the legacy path cannot be Treblized.

This change allows such devices to use HIDL IComposer, by adding
support for FB HAL in the default implementation.

Test: boots hikey960
Change-Id: Ie9050bbcaac0fd5b134786f4f9f0f5075f4ebd0c

graphics/composer/2.1/default/Hwc.cpp

diff --git a/graphics/composer/2.1/default/Hwc.cpp b/graphics/composer/2.1/default/Hwc.cpp
index 1618dcc..fdb4af8 100644
--- a/graphics/composer/2.1/default/Hwc.cpp
+++ b/graphics/composer/2.1/default/Hwc.cpp
@@ -23,8 +23,10 @@
 #include <log/log.h>
 
 #include "ComposerClient.h"
+#include "hardware/fb.h"
 #include "hardware/hwcomposer.h"
 #include "hwc2on1adapter/HWC2On1Adapter.h"
+#include "hwc2onfbadapter/HWC2OnFbAdapter.h"
 
 using namespace std::chrono_literals;
 
@@ -37,6 +39,30 @@
 
 HwcHal::HwcHal(const hw_module_t* module)
     : mDevice(nullptr), mDispatch(), mMustValidateDisplay(true), mAdapter() {
+    uint32_t majorVersion;
+    if (module->id && strcmp(module->id, GRALLOC_HARDWARE_MODULE_ID) == 0) {
+        majorVersion = initWithFb(module);
+    } else {
+        majorVersion = initWithHwc(module);
+    }
+
+    initCapabilities();
+    if (majorVersion >= 2 &&
+        hasCapability(Capability::PRESENT_FENCE_IS_NOT_RELIABLE)) {
+        ALOGE("Present fence must be reliable from HWC2 on.");
+        abort();
+    }
+
+    initDispatch();
+}
+
+HwcHal::~HwcHal()
+{
+    hwc2_close(mDevice);
+}
+
+uint32_t HwcHal::initWithHwc(const hw_module_t* module)
+{
     // Determine what kind of module is available (HWC2 vs HWC1.X).
     hw_device_t* device = nullptr;
     int error = module->methods->open(module, HWC_HARDWARE_COMPOSER, &device);
@@ -65,19 +91,22 @@
         mDevice = reinterpret_cast<hwc2_device_t*>(device);
     }
 
-    initCapabilities();
-    if (majorVersion >= 2 &&
-        hasCapability(Capability::PRESENT_FENCE_IS_NOT_RELIABLE)) {
-        ALOGE("Present fence must be reliable from HWC2 on.");
+    return majorVersion;
+}
+
+uint32_t HwcHal::initWithFb(const hw_module_t* module)
+{
+    framebuffer_device_t* fb_device;
+    int error = framebuffer_open(module, &fb_device);
+    if (error != 0) {
+        ALOGE("Failed to open FB device (%s), aborting", strerror(-error));
         abort();
     }
 
-    initDispatch();
-}
+    mFbAdapter = std::make_unique<HWC2OnFbAdapter>(fb_device);
+    mDevice = mFbAdapter.get();
 
-HwcHal::~HwcHal()
-{
-    hwc2_close(mDevice);
+    return 0;
 }
 
 void HwcHal::initCapabilities()
@@ -757,7 +786,11 @@
     const hw_module_t* module = nullptr;
     int err = hw_get_module(HWC_HARDWARE_MODULE_ID, &module);
     if (err) {
-        ALOGE("failed to get hwcomposer module");
+        ALOGI("falling back to FB HAL");
+        err = hw_get_module(GRALLOC_HARDWARE_MODULE_ID, &module);
+    }
+    if (err) {
+        ALOGE("failed to get hwcomposer or fb module");
         return nullptr;
     }