From: Sam Bobroff <sbobroff@linux.ibm.com>
Date: Mon, 5 Nov 2018 05:57:47 +0000 (+1100)
Subject: drm/ast: Fix incorrect free on ioregs
X-Git-Tag: v5.15~7520^2~5
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=dc25ab067645eabd037f1a23d49a666f9e0b8c68;p=platform%2Fkernel%2Flinux-starfive.git

drm/ast: Fix incorrect free on ioregs

If the platform has no IO space, ioregs is placed next to the already
allocated regs. In this case, it should not be separately freed.

This prevents a kernel warning from __vunmap "Trying to vfree()
nonexistent vm area" when unloading the driver.

Fixes: 0dd68309b9c5 ("drm/ast: Try to use MMIO registers when PIO isn't supported")

Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>
---

diff --git a/drivers/gpu/drm/ast/ast_main.c b/drivers/gpu/drm/ast/ast_main.c
index dac3558..373700c 100644
--- a/drivers/gpu/drm/ast/ast_main.c
+++ b/drivers/gpu/drm/ast/ast_main.c
@@ -583,7 +583,8 @@ void ast_driver_unload(struct drm_device *dev)
 	drm_mode_config_cleanup(dev);
 
 	ast_mm_fini(ast);
-	pci_iounmap(dev->pdev, ast->ioregs);
+	if (ast->ioregs != ast->regs + AST_IO_MM_OFFSET)
+		pci_iounmap(dev->pdev, ast->ioregs);
 	pci_iounmap(dev->pdev, ast->regs);
 	kfree(ast);
 }