commit 90f783f3ca34134298c6220b9223da08319804b3
author Kelvin Zhang <zhangkelvin@google.com> Tue Mar 30 08:59:19 2021 -0400
committer Kelvin Zhang <zhangkelvin@google.com> Mon May 17 16:25:00 2021 -0400
tree 32a8e6dc57066241bb06cc5fa05790d64f46e5fd
parent 9df2d8e6bd3520fd060804051fddae03dfa15267

use create_dumb.size as size of buffer

According to `man drm-memory` , "The size field contains the absolute
size in bytes of the buffer. This can normally also be computed with
(height * pitch + width) * bpp / 4". Which suggests that we should use
the .size field to allocate buffer.

Test: th
Test: go to recovery, make sure contents are properly displayed.

BYPASS_INCLUSIVE_LANGUAGE_REASON=commit message referenced "man",
        which is a linux command for lookup manual pages.

Change-Id: I512be6b7d493ef1783f2b7f746e279bc1dfe65f2

minui/graphics_drm.cpp

diff --git a/minui/graphics_drm.cpp b/minui/graphics_drm.cpp
index 95759e3..9d31ff7 100644
--- a/minui/graphics_drm.cpp
+++ b/minui/graphics_drm.cpp
@@ -105,6 +105,8 @@
     perror("Failed to DRM_IOCTL_MODE_CREATE_DUMB");
     return nullptr;
   }
+  printf("Allocating buffer with resolution %d x %d pitch: %d bpp: %d, size: %llu\n", width, height,
+         create_dumb.pitch, create_dumb.bpp, create_dumb.size);
 
   // Cannot use std::make_unique to access non-public ctor.
   auto surface = std::unique_ptr<GRSurfaceDrm>(new GRSurfaceDrm(
@@ -128,13 +130,14 @@
     return nullptr;
   }
 
-  auto mmapped = mmap(nullptr, surface->height * surface->row_bytes, PROT_READ | PROT_WRITE,
-                      MAP_SHARED, drm_fd, map_dumb.offset);
+  auto mmapped =
+      mmap(nullptr, create_dumb.size, PROT_READ | PROT_WRITE, MAP_SHARED, drm_fd, map_dumb.offset);
   if (mmapped == MAP_FAILED) {
     perror("Failed to mmap()");
     return nullptr;
   }
   surface->mmapped_buffer_ = static_cast<uint8_t*>(mmapped);
+  printf("Framebuffer of size %llu allocated @ %p\n", create_dumb.size, surface->mmapped_buffer_);
   return surface;
 }
 
@@ -260,9 +263,16 @@
   /* If we still didn't find a connector, give up and return. */
   if (!main_monitor_connector) return nullptr;
 
+  for (int modes = 0; modes < main_monitor_connector->count_modes; modes++) {
+    printf("Display Mode %d resolution: %d x %d @ %d FPS\n", modes,
+           main_monitor_connector->modes[modes].hdisplay,
+           main_monitor_connector->modes[modes].vdisplay,
+           main_monitor_connector->modes[modes].vrefresh);
+  }
   *mode_index = 0;
   for (int modes = 0; modes < main_monitor_connector->count_modes; modes++) {
     if (main_monitor_connector->modes[modes].type & DRM_MODE_TYPE_PREFERRED) {
+      printf("Choosing display mode #%d\n", modes);
       *mode_index = modes;
       break;
     }