[PATCH 1/2 v2] x86, ia64: Move EFI_FB vga_default_device() initialization to pci_vga_fixup()

["Bruno Prémont" <bonbons@linux-vserver.org>]

With commit b4aa0163056b ("efifb: Implement vga_default_device() (v2)")
Matthew Garrett introduced a efifb vga_default_device() so that EFI
systems that do not load shadow VBIOS or setup VGA get proper value for
boot_vga PCI sysfs attribute on the corresponding PCI device.

Xorg is refusing to detect devices when boot_vga=0 which is the case on
some EFI system (e.g. MacBookAir2,1). Xorg detects the GPU and finds
the dri device but then bails out with "no devices detected".

Note: When vga_default_device() is set boot_vga PCI sysfs attribute
reflects its state. When unset this attribute is 1 whenever
IORESOURCE_ROM_SHADOW flag is set.

With introduction of sysfb/simplefb/simpledrm efifb is getting obsolete
while having native drivers for the GPU also makes selecting
sysfb/efifb optional.

Remove the efifb implementation of vga_default_device() and initialize
vgaarb's vga_default_device() with the PCI GPU that matches boot
screen_info in pci_fixup_video().

Tested-by: Anibal Francisco Martinez Cortina <linuxkid.zeuz@gmail.com>
Cc: Matthew Garrett <matthew.garrett@nebula.com>
Cc: stable@vger.kernel.org
Signed-off-by: Bruno Prémont <bonbons@linux-vserver.org>
---

Changes since v1:
  Added Tested-by, Cc

 arch/ia64/pci/fixup.c       | 21 +++++++++++++++++++++
 arch/x86/include/asm/vga.h  |  6 ------
 arch/x86/pci/fixup.c        | 21 +++++++++++++++++++++
 drivers/video/fbdev/efifb.c | 38 --------------------------------------
 4 files changed, 42 insertions(+), 44 deletions(-)

diff --git a/arch/ia64/pci/fixup.c b/arch/ia64/pci/fixup.c
index eee069a..9ed5bef 100644
--- a/arch/ia64/pci/fixup.c
+++ b/arch/ia64/pci/fixup.c
@@ -37,6 +37,27 @@ static void pci_fixup_video(struct pci_dev *pdev)
 		return;
 	/* Maybe, this machine supports legacy memory map. */
 
+	if (!vga_default_device()) {
+		resource_size_t start, end;
+		int i;
+
+		/* Does firmware framebuffer belong to us? */
+		for (i=0; i < DEVICE_COUNT_RESOURCE; i++) {
+			if (!(pci_resource_flags(pdev, i) & IORESOURCE_MEM))
+				continue;
+
+			start = pci_resource_start(pdev, i);
+			end  = pci_resource_end(pdev, i);
+
+			if (!start || !end)
+				continue;
+
+			if (screen_info.lfb_base >= start &&
+				(screen_info.lfb_base + screen_info.lfb_size) < end)
+				vga_set_default_device(pdev);
+		}
+	}
+
 	/* Is VGA routed to us? */
 	bus = pdev->bus;
 	while (bus) {
diff --git a/arch/x86/include/asm/vga.h b/arch/x86/include/asm/vga.h
index 44282fb..c4b9dc2 100644
--- a/arch/x86/include/asm/vga.h
+++ b/arch/x86/include/asm/vga.h
@@ -17,10 +17,4 @@
 #define vga_readb(x) (*(x))
 #define vga_writeb(x, y) (*(y) = (x))
 
-#ifdef CONFIG_FB_EFI
-#define __ARCH_HAS_VGA_DEFAULT_DEVICE
-extern struct pci_dev *vga_default_device(void);
-extern void vga_set_default_device(struct pci_dev *pdev);
-#endif
-
 #endif /* _ASM_X86_VGA_H */
diff --git a/arch/x86/pci/fixup.c b/arch/x86/pci/fixup.c
index 94ae9ae..7246cf2 100644
--- a/arch/x86/pci/fixup.c
+++ b/arch/x86/pci/fixup.c
@@ -325,6 +325,27 @@ static void pci_fixup_video(struct pci_dev *pdev)
 	struct pci_bus *bus;
 	u16 config;
 
+	if (!vga_default_device()) {
+		resource_size_t start, end;
+		int i;
+
+		/* Does firmware framebuffer belong to us? */
+		for (i=0; i < DEVICE_COUNT_RESOURCE; i++) {
+			if (!(pci_resource_flags(pdev, i) & IORESOURCE_MEM))
+				continue;
+
+			start = pci_resource_start(pdev, i);
+			end  = pci_resource_end(pdev, i);
+
+			if (!start || !end)
+				continue;
+
+			if (screen_info.lfb_base >= start &&
+				(screen_info.lfb_base + screen_info.lfb_size) < end)
+				vga_set_default_device(pdev);
+		}
+	}
+
 	/* Is VGA routed to us? */
 	bus = pdev->bus;
 	while (bus) {
diff --git a/drivers/video/fbdev/efifb.c b/drivers/video/fbdev/efifb.c
index ae9618f..a033180 100644
--- a/drivers/video/fbdev/efifb.c
+++ b/drivers/video/fbdev/efifb.c
@@ -19,8 +19,6 @@
 
 static bool request_mem_succeeded = false;
 
-static struct pci_dev *default_vga;
-
 static struct fb_var_screeninfo efifb_defined = {
 	.activate		= FB_ACTIVATE_NOW,
 	.height			= -1,
@@ -84,18 +82,6 @@ static struct fb_ops efifb_ops = {
 	.fb_imageblit	= cfb_imageblit,
 };
 
-struct pci_dev *vga_default_device(void)
-{
-	return default_vga;
-}
-
-EXPORT_SYMBOL_GPL(vga_default_device);
-
-void vga_set_default_device(struct pci_dev *pdev)
-{
-	default_vga = pdev;
-}
-
 static int efifb_setup(char *options)
 {
 	char *this_opt;
@@ -126,30 +112,6 @@ static int efifb_setup(char *options)
 		}
 	}
 
-	for_each_pci_dev(dev) {
-		int i;
-
-		if ((dev->class >> 8) != PCI_CLASS_DISPLAY_VGA)
-			continue;
-
-		for (i=0; i < DEVICE_COUNT_RESOURCE; i++) {
-			resource_size_t start, end;
-
-			if (!(pci_resource_flags(dev, i) & IORESOURCE_MEM))
-				continue;
-
-			start = pci_resource_start(dev, i);
-			end  = pci_resource_end(dev, i);
-
-			if (!start || !end)
-				continue;
-
-			if (screen_info.lfb_base >= start &&
-			    (screen_info.lfb_base + screen_info.lfb_size) < end)
-				default_vga = dev;
-		}
-	}
-
 	return 0;
 }
 
-- 
1.8.5.5