Commit ce027dac authored by Bruno Prémont's avatar Bruno Prémont Committed by Greg Kroah-Hartman

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

commit 86fd887b upstream.

Commit 20cde694 ("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=84461Reported-and-Tested-By: default avatarAndreas Noever <andreas.noever@gmail.com>
Signed-off-by: default avatarBruno Prémont <bonbons@linux-vserver.org>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
CC: Matthew Garrett <matthew.garrett@nebula.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 7babfd7f
......@@ -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");
}
}
}
......
......@@ -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");
}
}
}
......
......@@ -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>
......@@ -580,8 +581,11 @@ 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);
......@@ -1316,6 +1320,38 @@ 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
......
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