fpga: altera-cvp: fix 'bad IO access' on x86_64

If mapping the CvP BAR fails, we still can configure the FPGA via
PCI config space access. In this case the iomap pointer is NULL.
On x86_64, passing NULL address to pci_iounmap() generates
"Bad IO access at port 0x0" output with stack call trace. Fix it.

Signed-off-by: Anatolij Gustschin <agust@denx.de>
Acked-by: Alan Tull <atull@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 4 insertions, 2 deletions

diff --git a/drivers/fpga/altera-cvp.c b/drivers/fpga/altera-cvp.c
index 610a1558e0ed..144fa2a4d4cc 100644
--- a/drivers/fpga/altera-cvp.c
+++ b/drivers/fpga/altera-cvp.c
@@ -477,7 +477,8 @@ static int altera_cvp_probe(struct pci_dev *pdev,
         return 0;
 
 err_unmap:
-        pci_iounmap(pdev, conf->map);
+        if (conf->map)
+                pci_iounmap(pdev, conf->map);
         pci_release_region(pdev, CVP_BAR);
 err_disable:
         cmd &= ~PCI_COMMAND_MEMORY;
@@ -493,7 +494,8 @@ static void altera_cvp_remove(struct pci_dev *pdev)
 
         driver_remove_file(&altera_cvp_driver.driver, &driver_attr_chkcfg);
         fpga_mgr_unregister(mgr);
-        pci_iounmap(pdev, conf->map);
+        if (conf->map)
+                pci_iounmap(pdev, conf->map);
         pci_release_region(pdev, CVP_BAR);
         pci_read_config_word(pdev, PCI_COMMAND, &cmd);
         cmd &= ~PCI_COMMAND_MEMORY;