diff options
| author | Stephen Kitt <steve@sk2.org> | 2011-01-31 14:25:43 -0800 |
|---|---|---|
| committer | Dave Airlie <airlied@redhat.com> | 2011-02-04 09:43:57 +1000 |
| commit | a70b95c017e8b518e1e069853355e4e497453dbb (patch) | |
| tree | c4264dc861b449f83fc40d9fb942083c5d985870 | |
| parent | cecd1455bc9cbd9568036f502ee8ded0a64354a7 (diff) | |
agp: ensure GART has an address before enabling it
Some BIOSs (eg. the AMI BIOS on the Asus P4P800 motherboard) don't
initialise the GART address, and pcibios_assign_resources() can ignore it
because it can be marked as a host bridge (see
https://bugzilla.kernel.org/show_bug.cgi?id=24392#c5 for details). This
was handled correctly up to 2.6.35, but the pci_enable_device() cleanup in
2.6.36 96576a9e1a0cdb8 ("agp: intel-agp: do not use PCI resources before
pci_enable_device()") means that the kernel tries to enable the GART
before assigning it an address; in such cases the GART overlaps with other
device assignments and ends up being disabled.
This patch fixes https://bugzilla.kernel.org/show_bug.cgi?id=24392
Note that I imagine efficeon-agp.c probably has the same problem, but
I can't test that and I'd like to make sure this patch is suitable for
-stable (since 2.6.36 and 2.6.37 are affected).
Signed-off-by: Stephen Kitt <steve@sk2.org>
Cc: Bjorn Helgaas <bjorn.helgaas@hp.com>
Cc: Maciej Rutecki <maciej.rutecki@gmail.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Kulikov Vasiliy <segooon@gmail.com>
Cc: Florian Mickler <florian@mickler.org>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>
| -rw-r--r-- | drivers/char/agp/intel-agp.c | 27 |
1 files changed, 16 insertions, 11 deletions
diff --git a/drivers/char/agp/intel-agp.c b/drivers/char/agp/intel-agp.c index 857df10c042..b0a0dccc98c 100644 --- a/drivers/char/agp/intel-agp.c +++ b/drivers/char/agp/intel-agp.c @@ -774,20 +774,14 @@ static int __devinit agp_intel_probe(struct pci_dev *pdev, dev_info(&pdev->dev, "Intel %s Chipset\n", intel_agp_chipsets[i].name); /* - * If the device has not been properly setup, the following will catch - * the problem and should stop the system from crashing. - * 20030610 - hamish@zot.org - */ - if (pci_enable_device(pdev)) { - dev_err(&pdev->dev, "can't enable PCI device\n"); - agp_put_bridge(bridge); - return -ENODEV; - } - - /* * The following fixes the case where the BIOS has "forgotten" to * provide an address range for the GART. * 20030610 - hamish@zot.org + * This happens before pci_enable_device() intentionally; + * calling pci_enable_device() before assigning the resource + * will result in the GART being disabled on machines with such + * BIOSs (the GART ends up with a BAR starting at 0, which + * conflicts a lot of other devices). */ r = &pdev->resource[0]; if (!r->start && r->end) { @@ -798,6 +792,17 @@ static int __devinit agp_intel_probe(struct pci_dev *pdev, } } + /* + * If the device has not been properly setup, the following will catch + * the problem and should stop the system from crashing. + * 20030610 - hamish@zot.org + */ + if (pci_enable_device(pdev)) { + dev_err(&pdev->dev, "can't enable PCI device\n"); + agp_put_bridge(bridge); + return -ENODEV; + } + /* Fill in the mode register */ if (cap_ptr) { pci_read_config_dword(pdev, |