fbdev: hgafb: Request memory region before ioremap

The driver calls ioremap() on the HGA video memory at 0xb0000 without
first reserving the physical address range. This leaves the kernel
resource tree incomplete and can cause silent conflicts with other
drivers claiming the same range.

Add a devm_request_mem_region() call before ioremap() in
hga_card_detect() to reserve the memory region.

Signed-off-by: Hardik Phalet <hardik.phalet@pm.me>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Helge Deller <deller@gmx.de>

Author: Hardik Phalet

drivers/video/fbdev/hgafb.c

@@ -276,14 +276,19 @@ static void hga_blank(int blank_mode)
 	spin_unlock_irqrestore(&hga_reg_lock, flags);
 }
 
-static int hga_card_detect(void)
+static int hga_card_detect(struct platform_device *pdev)
 {
 	int count = 0;
 	void __iomem *p, *q;
 	unsigned short p_save, q_save;
 
 	hga_vram_len  = 0x08000;
 
+	if (!devm_request_mem_region(&pdev->dev, 0xb0000, hga_vram_len, "hgafb")) {
+		dev_err(&pdev->dev, "cannot reserve video memory at 0xb0000\n");
+		return -EBUSY;
+	}
+
 	hga_vram = ioremap(0xb0000, hga_vram_len);
 	if (!hga_vram)
 		return -ENOMEM;
@@ -568,7 +573,7 @@ static int hgafb_probe(struct platform_device *pdev)
 	struct fb_info *info;
 	int ret;
 
-	ret = hga_card_detect();
+	ret = hga_card_detect(pdev);
 	if (ret)
 		return ret;