linux-kernel - [PATCH v2 1/2] drm/ast: Fix incorrect free on ioregs

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Date:   Mon,  3 Dec 2018 11:53:20 +1100
From:   Sam Bobroff <sbobroff@...ux.ibm.com>
To:     daniel@...ll.ch, airlied@...hat.com, airlied@...ux.ie,
        dri-devel@...ts.freedesktop.org, linux-kernel@...r.kernel.org
Subject: [PATCH v2 1/2] 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@...ux.ibm.com>
---
 drivers/gpu/drm/ast/ast_main.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/ast/ast_main.c b/drivers/gpu/drm/ast/ast_main.c
index dac355812adc..373700c05a00 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);
 }
-- 
2.19.0.2.gcad72f5712