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From:   Ard Biesheuvel <ardb@kernel.org>
To:     linux-efi@vger.kernel.org, Ingo Molnar <mingo@kernel.org>,
        Thomas Gleixner <tglx@linutronix.de>
Cc:     Ard Biesheuvel <ardb@kernel.org>, linux-kernel@vger.kernel.org,
        Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        Arvind Sankar <nivedita@alum.mit.edu>,
        Bhupesh Sharma <bhsharma@redhat.com>,
        Masayoshi Mizuma <m.mizuma@jp.fujitsu.com>
Subject: [PATCH 2/6] efi/gop: Return EFI_NOT_FOUND if there are no usable GOPs
Date:   Fri,  6 Dec 2019 16:55:38 +0000
Message-Id: <20191206165542.31469-3-ardb@kernel.org>
In-Reply-To: <20191206165542.31469-1-ardb@kernel.org>
References: <20191206165542.31469-1-ardb@kernel.org>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

From: Arvind Sankar <nivedita@alum.mit.edu>

If we don't find a usable instance of the Graphics Output Protocol
(GOP) because none of them have a framebuffer (i.e. they were all
PIXEL_BLT_ONLY), but all the efi calls succeeded, we will return
EFI_SUCCESS even though we didn't find a usable GOP.

Fix this by explicitly returning EFI_NOT_FOUND if no usable GOPs are
found, allowing the caller to probe for UGA instead.

Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---
 drivers/firmware/efi/libstub/gop.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/firmware/efi/libstub/gop.c b/drivers/firmware/efi/libstub/gop.c
index 0101ca4c13b1..08f3c1a2fb48 100644
--- a/drivers/firmware/efi/libstub/gop.c
+++ b/drivers/firmware/efi/libstub/gop.c
@@ -119,7 +119,7 @@ setup_gop32(efi_system_table_t *sys_table_arg, struct screen_info *si,
 	u64 fb_base;
 	struct efi_pixel_bitmask pixel_info;
 	int pixel_format;
-	efi_status_t status = EFI_NOT_FOUND;
+	efi_status_t status;
 	u32 *handles = (u32 *)(unsigned long)gop_handle;
 	int i;
 
@@ -175,7 +175,7 @@ setup_gop32(efi_system_table_t *sys_table_arg, struct screen_info *si,
 
 	/* Did we find any GOPs? */
 	if (!first_gop)
-		goto out;
+		return EFI_NOT_FOUND;
 
 	/* EFI framebuffer */
 	si->orig_video_isVGA = VIDEO_TYPE_EFI;
@@ -197,7 +197,7 @@ setup_gop32(efi_system_table_t *sys_table_arg, struct screen_info *si,
 	si->lfb_size = si->lfb_linelength * si->lfb_height;
 
 	si->capabilities |= VIDEO_CAPABILITY_SKIP_QUIRKS;
-out:
+
 	return status;
 }
 
@@ -237,7 +237,7 @@ setup_gop64(efi_system_table_t *sys_table_arg, struct screen_info *si,
 	u64 fb_base;
 	struct efi_pixel_bitmask pixel_info;
 	int pixel_format;
-	efi_status_t status = EFI_NOT_FOUND;
+	efi_status_t status;
 	u64 *handles = (u64 *)(unsigned long)gop_handle;
 	int i;
 
@@ -293,7 +293,7 @@ setup_gop64(efi_system_table_t *sys_table_arg, struct screen_info *si,
 
 	/* Did we find any GOPs? */
 	if (!first_gop)
-		goto out;
+		return EFI_NOT_FOUND;
 
 	/* EFI framebuffer */
 	si->orig_video_isVGA = VIDEO_TYPE_EFI;
@@ -315,7 +315,7 @@ setup_gop64(efi_system_table_t *sys_table_arg, struct screen_info *si,
 	si->lfb_size = si->lfb_linelength * si->lfb_height;
 
 	si->capabilities |= VIDEO_CAPABILITY_SKIP_QUIRKS;
-out:
+
 	return status;
 }
 
-- 
2.17.1