@@ -146,6 +146,8 @@ ATTRIBUTE_GROUPS(efifb);
static bool pci_dev_disabled; /* FB base matches BAR of a disabled device */
+static struct resource *pci_dev_bar_resource;
+
static int efifb_probe(struct platform_device *dev)
{
struct fb_info *info;
@@ -179,6 +181,20 @@ static int efifb_probe(struct platform_device *dev)
}
printk(KERN_INFO "efifb: probing for efifb\n");
+ if (pci_dev_bar_resource) {
+ u64 base = screen_info.lfb_base;
+ u64 size = screen_info.lfb_size;
+
+ if (screen_info.capabilities & VIDEO_CAPABILITY_64BIT_BASE)
+ base |= (u64)screen_info.ext_lfb_base << 32;
+
+ if (pci_dev_bar_resource->start > base ||
+ pci_dev_bar_resource->end < base + size - 1) {
+ pr_err("efifb: PCI BAR has moved, disabling ...\n");
+ return -ENODEV;
+ }
+ }
+
/* just assume they're all unset if any are */
if (!screen_info.blue_size) {
screen_info.blue_size = 8;
@@ -383,12 +399,7 @@ static void claim_efifb_bar(struct pci_dev *dev, int idx)
return;
}
- if (pci_claim_resource(dev, idx)) {
- pci_dev_disabled = true;
- dev_err(&dev->dev,
- "BAR %d: failed to claim resource for efifb!\n", idx);
- return;
- }
+ pci_dev_bar_resource = dev->resource + idx;
dev_info(&dev->dev, "BAR %d: assigned to efifb\n", idx);
}
Claiming the BAR that matches the framebuffer base address in a PCI header fixup quirk only works as expected when the PCI device is on bus 0. If not, it will produce the following error: pci 0000:01:01.0: can't claim BAR 0 [mem 0x10000000-0x10ffffff pref]: no compatible bridge window pci 0000:01:01.0: BAR 0: failed to claim resource for efifb! Since claiming the entire path up to the root is non-trivial at this point, and also undesirable given that we have no way of making sure that the existing configuration is sound, let's not claim anything at all, and simply record the resource so we can check that it did not move when the EFI fb driver is probed. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> --- drivers/video/fbdev/efifb.c | 23 +++++++++++++++----- 1 file changed, 17 insertions(+), 6 deletions(-)