linux-kernel - [PATCH 10/12] drm/ast: Use devm aperture helpers for sysfb restore on probe failure

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Message-ID: <20251229215906.3688205-11-zack.rusin@broadcom.com>
Date: Mon, 29 Dec 2025 16:58:16 -0500
From: Zack Rusin <zack.rusin@...adcom.com>
To: dri-devel@...ts.freedesktop.org
Cc: Dave Airlie <airlied@...hat.com>,
	Thomas Zimmermann <tzimmermann@...e.de>,
	Jocelyn Falempe <jfalempe@...hat.com>,
	Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>,
	Maxime Ripard <mripard@...nel.org>,
	David Airlie <airlied@...il.com>,
	Simona Vetter <simona@...ll.ch>,
	linux-kernel@...r.kernel.org
Subject: [PATCH 10/12] drm/ast: Use devm aperture helpers for sysfb restore on probe failure

Use devm_aperture_remove_conflicting_pci_devices() instead of the
non-devm variant to automatically restore the system framebuffer
(efifb/simpledrm) if the driver's probe fails after removing the
firmware framebuffer.

Call devm_aperture_remove_conflicting_pci_devices_done() after
successful probe to cancel the automatic restore, as the driver
is now responsible for display output.

This ensures users don't lose display output if the ast driver
fails to probe after removing the firmware framebuffer.

Signed-off-by: Zack Rusin <zack.rusin@...adcom.com>
Cc: Dave Airlie <airlied@...hat.com>
Cc: Thomas Zimmermann <tzimmermann@...e.de>
Cc: Jocelyn Falempe <jfalempe@...hat.com>
Cc: Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>
Cc: Maxime Ripard <mripard@...nel.org>
Cc: David Airlie <airlied@...il.com>
Cc: Simona Vetter <simona@...ll.ch>
Cc: dri-devel@...ts.freedesktop.org
Cc: linux-kernel@...r.kernel.org
---
 drivers/gpu/drm/ast/ast_drv.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/ast/ast_drv.c b/drivers/gpu/drm/ast/ast_drv.c
index b9a9b050b546..8e6c7cbafa59 100644
--- a/drivers/gpu/drm/ast/ast_drv.c
+++ b/drivers/gpu/drm/ast/ast_drv.c
@@ -310,7 +310,12 @@ static int ast_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 	struct drm_device *drm;
 	bool need_post = false;
 
-	ret = aperture_remove_conflicting_pci_devices(pdev, ast_driver.name);
+	/*
+	 * Use devm variant to automatically restore sysfb if probe fails.
+	 * This ensures the user doesn't lose display if our probe fails
+	 * after removing the firmware framebuffer (efifb/simpledrm).
+	 */
+	ret = devm_aperture_remove_conflicting_pci_devices(pdev, ast_driver.name);
 	if (ret)
 		return ret;
 
@@ -426,6 +431,12 @@ static int ast_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 
 	drm_client_setup(drm, NULL);
 
+	/*
+	 * Probe succeeded - cancel the automatic sysfb restore action.
+	 * We're now responsible for display output.
+	 */
+	devm_aperture_remove_conflicting_pci_devices_done(pdev);
+
 	return 0;
 }
 
-- 
2.48.1