[PATCH] usb: gadget: amd5536udc: fix NULL pointer dereference

[Sudip Mukherjee]

We were checking if dev->regs is NULL but it was done after
dereferencing it. Lets reset the controller and iounmap dev->regs only
if it is not NULL.
free_irq() does not need dev->regs, so unmaping it before freeing the
irq should not matter.

Signed-off-by: Sudip Mukherjee <sudip@xxxxxxxxxxxxxxx>
---
 drivers/usb/gadget/udc/amd5536udc.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/gadget/udc/amd5536udc.c b/drivers/usb/gadget/udc/amd5536udc.c
index fdacddb..26066d3 100644
--- a/drivers/usb/gadget/udc/amd5536udc.c
+++ b/drivers/usb/gadget/udc/amd5536udc.c
@@ -3135,11 +3135,12 @@ static void udc_pci_remove(struct pci_dev *pdev)
 	}
 
 	/* reset controller */
-	writel(AMD_BIT(UDC_DEVCFG_SOFTRESET), &dev->regs->cfg);
+	if (dev->regs) {
+		writel(AMD_BIT(UDC_DEVCFG_SOFTRESET), &dev->regs->cfg);
+		iounmap(dev->regs);
+	}
 	if (dev->irq_registered)
 		free_irq(pdev->irq, dev);
-	if (dev->regs)
-		iounmap(dev->regs);
 	if (dev->mem_region)
 		release_mem_region(pci_resource_start(pdev, 0),
 				pci_resource_len(pdev, 0));
-- 
1.9.1

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