drm_hwcomposer: Fix HwcDisplay::GetDisplayIdentificationData()

Return Error::Unsupported in headless mode and if no EDID blob returned
by the kernel.

With this change GraphicsComposerHidlTest#GetDisplayIdentificationData
VTS no longer fails.

Also fix outPort assignment to avoid setting negative values
(handle_ is 0 for primary display).

Signed-off-by: Roman Stratiienko <roman.o.stratiienko@globallogic.com>

1 files changed, 5 insertions, 8 deletions

diff --git a/hwc2_device/HwcDisplay.cpp b/hwc2_device/HwcDisplay.cpp
index 48e0624..3956fc9 100644
--- a/hwc2_device/HwcDisplay.cpp
+++ b/hwc2_device/HwcDisplay.cpp
@@ -799,19 +799,16 @@ HWC2::Error HwcDisplay::GetDisplayIdentificationData(uint8_t *outPort,
                                                      uint32_t *outDataSize,
                                                      uint8_t *outData) {
   if (IsInHeadlessMode()) {
-    return HWC2::Error::None;
+    return HWC2::Error::Unsupported;
   }
-  auto blob = GetPipe().connector->Get()->GetEdidBlob();
-
-  *outPort = handle_ - 1;
 
+  auto blob = GetPipe().connector->Get()->GetEdidBlob();
   if (!blob) {
-    if (outData == nullptr) {
-      *outDataSize = 0;
-    }
-    return HWC2::Error::None;
+    return HWC2::Error::Unsupported;
   }
 
+  *outPort = handle_; /* TDOD(nobody): What should be here? */
+
   if (outData) {
     *outDataSize = std::min(*outDataSize, blob->length);
     memcpy(outData, blob->data, *outDataSize);