drm/ast: Fix incorrect free on ioregs

commit dc25ab067645eabd037f1a23d49a666f9e0b8c68 upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/gpu/drm/ast/ast_main.c b/drivers/gpu/drm/ast/ast_main.c
index 498a94069e6b2f037b7821dc373413be8a0e1d2d..1acebd64fdedd2c7762dc9877df90aebb23c3db4 100644 (file)
--- a/drivers/gpu/drm/ast/ast_main.c
+++ b/drivers/gpu/drm/ast/ast_main.c
@@ -557,7 +557,8 @@ int 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);
        return 0;