drm/amdgpu: Remove driver side BAR release before resize

PCI core handles releasing device's resources and their rollback in case of
failure of a BAR resizing operation. Releasing resource prior to calling
pci_resize_resource() prevents PCI core from restoring the BARs as they
were.

Remove driver-side release of BARs from the amdgpu driver.

Also remove the driver initiated assignment as pci_resize_resource() should
try to assign as much as possible. If the driver side call manages to get
more required resources assigned in some scenario, such a problem should be
fixed inside pci_resize_resource() instead.

Signed-off-by: Ilpo Järvinen <[email protected]>
Signed-off-by: Bjorn Helgaas <[email protected]>
Tested-by: Alex Bennée <[email protected]> # AVA, AMD GPU
Link: https://patch.msgid.link/[email protected]

drivers/gpu/drm/amd/amdgpu/amdgpu_device.c

@@ -1729,12 +1729,8 @@ int amdgpu_device_resize_fb_bar(struct amdgpu_device *adev)
 	pci_write_config_word(adev->pdev, PCI_COMMAND,
 			      cmd & ~PCI_COMMAND_MEMORY);
 
-	/* Free the VRAM and doorbell BAR, we most likely need to move both. */
+	/* Tear down doorbell as resizing will release BARs */
 	amdgpu_doorbell_fini(adev);
-	if (adev->asic_type >= CHIP_BONAIRE)
-		pci_release_resource(adev->pdev, 2);
-
-	pci_release_resource(adev->pdev, 0);
 
 	r = pci_resize_resource(adev->pdev, 0, rbar_size,
 				(adev->asic_type >= CHIP_BONAIRE) ? 1 << 5
@@ -1745,8 +1741,6 @@ int amdgpu_device_resize_fb_bar(struct amdgpu_device *adev)
 	else if (r && r != -ENOTSUPP)
 		dev_err(adev->dev, "Problem resizing BAR0 (%d).", r);
 
-	pci_assign_unassigned_bus_resources(adev->pdev->bus);
-
 	/* When the doorbell or fb BAR isn't available we have no chance of
 	 * using the device.
 	 */