x86, efi: Fix display detection in EFI boot stub

commit 70a479cbe80296d3113e65cc2f713a5101061daf upstream.

When booting under OVMF we have precisely one GOP device, and it
implements the ConOut protocol.

We break out of the loop when we look at it... and then promptly abort
because 'first_gop' never gets set. We should set first_gop *before*
breaking out of the loop. Yes, it doesn't really mean "first" any more,
but that doesn't matter. It's only a flag to indicate that a suitable
GOP was found.

In fact, we'd do just as well to initialise 'width' to zero in this
function, then just check *that* instead of first_gop. But I'll do the
minimal fix for now (and for stable@).

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Link: http://lkml.kernel.org/r/1358513837.2397.247.camel@shinybook.infradead.org
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: Matt Fleming <matt.fleming@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/x86/boot/compressed/eboot.c b/arch/x86/boot/compressed/eboot.c
index e87b0cac14b5e5d735ab21f9f3b163db52349938..ccae7e2d2038e8a25ee1f511097d4650e51d7289 100644 (file)
--- a/arch/x86/boot/compressed/eboot.c
+++ b/arch/x86/boot/compressed/eboot.c
@@ -316,10 +316,9 @@ static efi_status_t setup_gop(struct screen_info *si, efi_guid_t *proto,
                         * Once we've found a GOP supporting ConOut,
                         * don't bother looking any further.
                         */
+                       first_gop = gop;
                        if (conout_found)
                                break;
-
-                       first_gop = gop;
                }
        }