[PATCH 3/4] Prefer GOP devices which implement the pci_io protocol

[Matthew Garrett]

Some systems (especially Apple) implement multiple GOP devices representing
the same hardware. The preferred device is the one that also implements the
PCI io protocol.
---
 ChangeLog                 |    5 +++++
 grub-core/video/efi_gop.c |   38 +++++++++++++++++++++++++++++++++++++-
 2 files changed, 42 insertions(+), 1 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index e662f3d..26d779b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,10 @@
 2012-02-08  Matthew Garrett  <address@hidden>
 
+       * grub-core/video/efi_gop.c (check_protocol): Prefer GOP devices which
+       implement the pci_io protocol.
+
+2012-02-08  Matthew Garrett  <address@hidden>
+
        * grub-core/kern/efi/efi.c (grub_efi_get_variable): Add new function.
        * include/grub/efi/efi.h: Likewise.
        * include/grub/efi/api.h: Add guid for EFI-specified variables.
diff --git a/grub-core/video/efi_gop.c b/grub-core/video/efi_gop.c
index d14ae98..47e3ee9 100644
--- a/grub-core/video/efi_gop.c
+++ b/grub-core/video/efi_gop.c
@@ -28,11 +28,14 @@
 #include <grub/efi/api.h>
 #include <grub/efi/efi.h>
 #include <grub/efi/graphics_output.h>
+#include <grub/efi/pci.h>
 
 GRUB_MOD_LICENSE ("GPLv3+");
 
 static grub_efi_guid_t graphics_output_guid = GRUB_EFI_GOP_GUID;
+static grub_efi_guid_t pci_io_guid = GRUB_EFI_PCI_IO_GUID;
 static struct grub_efi_gop *gop;
+static grub_efi_handle_t gop_handle;
 static unsigned old_mode;
 static int restore_needed;
 
@@ -47,7 +50,40 @@ static struct
 static int
 check_protocol (void)
 {
-  gop = grub_efi_locate_protocol (&graphics_output_guid, 0);
+  grub_efi_handle_t *handle, *handles;
+  grub_efi_uintn_t num_handles;
+
+  handles = grub_efi_locate_handle (GRUB_EFI_BY_PROTOCOL,
+                                   &pci_io_guid, NULL, &num_handles);
+  if (!num_handles || !handles)
+    return 0;
+
+  for (handle = handles; num_handles--; handle++)
+    {
+      gop = grub_efi_open_protocol (*handle, &graphics_output_guid,
+                                   GRUB_EFI_OPEN_PROTOCOL_GET_PROTOCOL);
+      if (gop)
+       {
+         gop_handle = *handle;
+         break;
+       }
+    }
+
+  grub_free(handles);
+
+  if (!gop)
+    {
+      handles = grub_efi_locate_handle (GRUB_EFI_BY_PROTOCOL,
+                                       &graphics_output_guid, NULL, 
&num_handles);
+      gop = grub_efi_open_protocol (*handles, &graphics_output_guid,
+                                   GRUB_EFI_OPEN_PROTOCOL_GET_PROTOCOL);
+      if (gop)
+       {
+         gop_handle = *handles;
+       }
+      grub_free(handles);
+    }
+
   if (gop)
     return 1;
 
-- 
1.7.7.6