linux-kernel - [PATCH 8/9] drm/amdgpu: Remove driver side BAR release before resize

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Message-Id: <20251028173551.22578-9-ilpo.jarvinen@linux.intel.com>
Date: Tue, 28 Oct 2025 19:35:50 +0200
From: Ilpo Järvinen <ilpo.jarvinen@...ux.intel.com>
To: Alex Bennée <alex.bennee@...aro.org>,
	Simon Richter <Simon.Richter@...yros.de>,
	Lucas De Marchi <lucas.demarchi@...el.com>,
	Alex Deucher <alexander.deucher@....com>,
	amd-gfx@...ts.freedesktop.org,
	Bjorn Helgaas <bhelgaas@...gle.com>,
	David Airlie <airlied@...il.com>,
	dri-devel@...ts.freedesktop.org,
	intel-gfx@...ts.freedesktop.org,
	intel-xe@...ts.freedesktop.org,
	Jani Nikula <jani.nikula@...ux.intel.com>,
	Joonas Lahtinen <joonas.lahtinen@...ux.intel.com>,
	linux-pci@...r.kernel.org,
	Rodrigo Vivi <rodrigo.vivi@...el.com>,
	Simona Vetter <simona@...ll.ch>,
	Tvrtko Ursulin <tursulin@...ulin.net>,
	Christian König <christian.koenig@....com>,
	Thomas Hellström <thomas.hellstrom@...ux.intel.com>,
	Michał Winiarski <michal.winiarski@...el.com>,
	linux-kernel@...r.kernel.org
Cc: Ilpo Järvinen <ilpo.jarvinen@...ux.intel.com>
Subject: [PATCH 8/9] 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 <ilpo.jarvinen@...ux.intel.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 8 +-------
 1 file changed, 1 insertion(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
index 7a899fb4de29..65474d365229 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
+++ b/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);
 	if (r == -ENOSPC)
@@ -1743,8 +1739,6 @@ 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.
 	 */
-- 
2.39.5