vgaarb: Don't default exclusively to first video device with mem+io

Commit 20cde694027e ("x86, ia64: Move EFI_FB vga_default_device()
initialization to pci_vga_fixup()") moved boot video device detection from
efifb to x86 and ia64 pci/fixup.c.

For dual-GPU Apple computers above change represents a regression as code
in efifb did forcefully override vga_default_device while the merge did not
(vgaarb happens prior to PCI fixup).

To improve on initial device selection by vgaarb (it cannot know if PCI
device not behind bridges see/decode legacy VGA I/O or not), move the
screen_info based check from pci_video_fixup() to vgaarb's init function and
use it to refine/override decision taken while adding the individual PCI
VGA devices.  This way PCI fixup has no reason to adjust vga_default_device
anymore but can depend on its value for flagging shadowed VBIOS.

This has the nice benefit of removing duplicated code but does introduce a
#if defined() block in vgaarb.  Not all architectures have screen_info and
would cause compile to fail without it.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=84461
Reported-and-Tested-By: Andreas Noever <andreas.noever@gmail.com>
Signed-off-by: Bruno Prémont <bonbons@linux-vserver.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
CC: Matthew Garrett <matthew.garrett@nebula.com>
CC: stable@vger.kernel.org # v3.5+

diff --git a/arch/ia64/pci/fixup.c b/arch/ia64/pci/fixup.c
index ec73b2cf912a45d2ce350c26bd19e0de54c09e75..fc505d58f078ecfb55210cd3e802ed23c4b41a8e 100644 (file)
--- a/arch/ia64/pci/fixup.c
+++ b/arch/ia64/pci/fixup.c
@@ -38,27 +38,6 @@ 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) {
@@ -83,8 +62,7 @@ static void pci_fixup_video(struct pci_dev *pdev)
                pci_read_config_word(pdev, PCI_COMMAND, &config);
                if (config & (PCI_COMMAND_IO | PCI_COMMAND_MEMORY)) {
                        pdev->resource[PCI_ROM_RESOURCE].flags |= IORESOURCE_ROM_SHADOW;
-                       dev_printk(KERN_DEBUG, &pdev->dev, "Boot video device\n");
-                       vga_set_default_device(pdev);
+                       dev_printk(KERN_DEBUG, &pdev->dev, "Video device with shadowed ROM\n");
                }
        }
 }

diff --git a/arch/x86/pci/fixup.c b/arch/x86/pci/fixup.c
index c61ea57d1ba1d9e8124a039d6aec59d1163c1c75..9a2b7101ae8af6d402f15c66831bcd15b7790325 100644 (file)
--- a/arch/x86/pci/fixup.c
+++ b/arch/x86/pci/fixup.c
@@ -326,27 +326,6 @@ 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) {
@@ -371,8 +350,7 @@ static void pci_fixup_video(struct pci_dev *pdev)
                pci_read_config_word(pdev, PCI_COMMAND, &config);
                if (config & (PCI_COMMAND_IO | PCI_COMMAND_MEMORY)) {
                        pdev->resource[PCI_ROM_RESOURCE].flags |= IORESOURCE_ROM_SHADOW;
-                       dev_printk(KERN_DEBUG, &pdev->dev, "Boot video device\n");
-                       vga_set_default_device(pdev);
+                       dev_printk(KERN_DEBUG, &pdev->dev, "Video device with shadowed ROM\n");
                }
        }
 }

diff --git a/drivers/gpu/vga/vgaarb.c b/drivers/gpu/vga/vgaarb.c
index d2077f040f3ec87f0922b8eb67db413539851e53..24ac52e6cd4118f32e46036832949807ef9870e7 100644 (file)
--- a/drivers/gpu/vga/vgaarb.c
+++ b/drivers/gpu/vga/vgaarb.c
@@ -41,6 +41,7 @@
 #include <linux/poll.h>
 #include <linux/miscdevice.h>
 #include <linux/slab.h>
+#include <linux/screen_info.h>
 
 #include <linux/uaccess.h>
 
@@ -585,8 +586,11 @@ static bool vga_arbiter_add_pci_device(struct pci_dev *pdev)
         */
 #ifndef __ARCH_HAS_VGA_DEFAULT_DEVICE
        if (vga_default == NULL &&
-           ((vgadev->owns & VGA_RSRC_LEGACY_MASK) == VGA_RSRC_LEGACY_MASK))
+           ((vgadev->owns & VGA_RSRC_LEGACY_MASK) == VGA_RSRC_LEGACY_MASK)) {
+               pr_info("vgaarb: setting as boot device: PCI:%s\n",
+                       pci_name(pdev));
                vga_set_default_device(pdev);
+       }
 #endif
 
        vga_arbiter_check_bridge_sharing(vgadev);
@@ -1320,6 +1324,38 @@ static int __init vga_arb_device_init(void)
        pr_info("vgaarb: loaded\n");
 
        list_for_each_entry(vgadev, &vga_list, list) {
+#if defined(CONFIG_X86) || defined(CONFIG_IA64)
+               /* Override I/O based detection done by vga_arbiter_add_pci_device()
+                * as it may take the wrong device (e.g. on Apple system under EFI).
+                *
+                * Select the device owning the boot framebuffer if there is one.
+                */
+               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(vgadev->pdev, i) & IORESOURCE_MEM))
+                               continue;
+
+                       start = pci_resource_start(vgadev->pdev, i);
+                       end  = pci_resource_end(vgadev->pdev, i);
+
+                       if (!start || !end)
+                               continue;
+
+                       if (screen_info.lfb_base < start ||
+                           (screen_info.lfb_base + screen_info.lfb_size) >= end)
+                               continue;
+                       if (!vga_default_device())
+                               pr_info("vgaarb: setting as boot device: PCI:%s\n",
+                                       pci_name(vgadev->pdev));
+                       else if (vgadev->pdev != vga_default_device())
+                               pr_info("vgaarb: overriding boot device: PCI:%s\n",
+                                       pci_name(vgadev->pdev));
+                       vga_set_default_device(vgadev->pdev);
+               }
+#endif
                if (vgadev->bridge_has_one_vga)
                        pr_info("vgaarb: bridge control possible %s\n", pci_name(vgadev->pdev));
                else