Don't even try to resize the BAR when there is no window above 4GB.
Signed-off-by: Christian König <christian.koenig at amd.com>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 18 ++++++++++++++++++
1 file changed, 18 insertions(+)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
index 4944f8e1577b..b5a8afdcfb5d 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
@@ -765,6 +765,9 @@ int amdgpu_device_resize_fb_bar(struct amdgpu_device *adev)
{
u64 space_needed = roundup_pow_of_two(adev->mc.real_vram_size);
u32 rbar_size = order_base_2(((space_needed >> 20) | 1)) - 1;
+ struct pci_bus *root;
+ struct resource *res;
+ unsigned i;
u16 cmd;
int r;
@@ -772,6 +775,21 @@ int amdgpu_device_resize_fb_bar(struct amdgpu_device *adev)
if (amdgpu_sriov_vf(adev))
return 0;
+ /* Check if the root BUS has 64bit memory resources */
+ root = adev->pdev->bus;
+ while (root->parent)
+ root = root->parent;
+
+ pci_bus_for_each_resource(root, res, i) {
+ if (res && res->flags & IORESOURCE_MEM_64 &&
+ res->start > 0x100000000ull)
+ break;
+ }
+
+ /* Trying to resize is pointless without a root hub window above 4GB */
+ if (!res)
+ return 0;
+
/* Disable memory decoding while we change the BAR addresses and size */
pci_read_config_word(adev->pdev, PCI_COMMAND, &cmd);
pci_write_config_word(adev->pdev, PCI_COMMAND,
--
2.11.0
