[PATCH] fbdev: geode: gxfb: Use devm_request_mem_region

From: Swaraj Gaikwad <hidden>
Date: 2025-12-13 19:44:28
Also in: dri-devel, lkml

The gxfb driver currently uses pci_request_region() for memory
reservation, which requires manual error handling and cleanup using
pci_release_region().

Simplify the driver by migrating to the managed helper
devm_request_mem_region(). This ensures that resources are automatically
released on driver detach, allowing the removal of explicit cleanup code
in the probe error path and the remove function.

This addresses the TODO item "Request memory regions in all fbdev
drivers" in Documentation/gpu/todo.rst.

Signed-off-by: Swaraj Gaikwad <redacted>
---
Compile-tested only on x86_64.

 drivers/video/fbdev/geode/gxfb_core.c | 36 +++++++++++----------------
 1 file changed, 15 insertions(+), 21 deletions(-)

diff --git a/drivers/video/fbdev/geode/gxfb_core.c b/drivers/video/fbdev/geode/gxfb_core.c
index 8d69be7c9d31..05af546c8c92 100644
--- a/drivers/video/fbdev/geode/gxfb_core.c
+++ b/drivers/video/fbdev/geode/gxfb_core.c

@@ -223,31 +223,33 @@ static int gxfb_map_video_memory(struct fb_info *info, struct pci_dev *dev)
 	if (ret < 0)
 		return ret;

-	ret = pci_request_region(dev, 3, "gxfb (video processor)");
-	if (ret < 0)
-		return ret;
+	if (!devm_request_mem_region(&dev->dev, pci_resource_start(dev, 3),
+			      pci_resource_len(dev, 3), "gxfb (video processor)"))
+		return -EBUSY;
+
 	par->vid_regs = pci_ioremap_bar(dev, 3);
 	if (!par->vid_regs)
 		return -ENOMEM;

-	ret = pci_request_region(dev, 2, "gxfb (display controller)");
-	if (ret < 0)
-		return ret;
+	if (!devm_request_mem_region(&dev->dev, pci_resource_start(dev, 2),
+			      pci_resource_len(dev, 2), "gxfb (display controller)"))
+		return -EBUSY;
+
 	par->dc_regs = pci_ioremap_bar(dev, 2);
 	if (!par->dc_regs)
 		return -ENOMEM;

-	ret = pci_request_region(dev, 1, "gxfb (graphics processor)");
-	if (ret < 0)
-		return ret;
-	par->gp_regs = pci_ioremap_bar(dev, 1);
+	if (!devm_request_mem_region(&dev->dev, pci_resource_start(dev, 1),
+			      pci_resource_len(dev, 1), "gxfb (graphics processor)"))
+		return -EBUSY;

+	par->gp_regs = pci_ioremap_bar(dev, 1);
 	if (!par->gp_regs)
 		return -ENOMEM;

-	ret = pci_request_region(dev, 0, "gxfb (framebuffer)");
-	if (ret < 0)
-		return ret;
+	if (!devm_request_mem_region(&dev->dev, pci_resource_start(dev, 0),
+			      pci_resource_len(dev, 0), "gxfb (framebuffer)"))
+		return -EBUSY;

 	info->fix.smem_start = pci_resource_start(dev, 0);
 	info->fix.smem_len = vram ? vram : gx_frame_buffer_size();

@@ -414,19 +416,15 @@ static int gxfb_probe(struct pci_dev *pdev, const struct pci_device_id *id)
   err:
 	if (info->screen_base) {
 		iounmap(info->screen_base);
-		pci_release_region(pdev, 0);
 	}
 	if (par->vid_regs) {
 		iounmap(par->vid_regs);
-		pci_release_region(pdev, 3);
 	}
 	if (par->dc_regs) {
 		iounmap(par->dc_regs);
-		pci_release_region(pdev, 2);
 	}
 	if (par->gp_regs) {
 		iounmap(par->gp_regs);
-		pci_release_region(pdev, 1);
 	}

 	fb_dealloc_cmap(&info->cmap);

@@ -442,16 +440,12 @@ static void gxfb_remove(struct pci_dev *pdev)
 	unregister_framebuffer(info);

 	iounmap((void __iomem *)info->screen_base);
-	pci_release_region(pdev, 0);

 	iounmap(par->vid_regs);
-	pci_release_region(pdev, 3);

 	iounmap(par->dc_regs);
-	pci_release_region(pdev, 2);

 	iounmap(par->gp_regs);
-	pci_release_region(pdev, 1);

 	fb_dealloc_cmap(&info->cmap);

base-commit: a859eca0e4cc96f63ff125dbe5388d961558b0e9
--
2.52.0

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