libpci: mmio-ports: Check for write access to /dev/mem in detect method

diff --git a/lib/mmio-ports.c b/lib/mmio-ports.c
index 50cbee7401a1bf83b9b524e4a44e878c6b69d56e..ae9c30d7fd6a00205c116d9523b78942af4f671e 100644 (file)
--- a/lib/mmio-ports.c
+++ b/lib/mmio-ports.c
@@ -243,9 +243,9 @@ conf1_detect(struct pci_access *a)
       return 0;
     }
 
-  if (access(devmem, R_OK))
+  if (access(devmem, R_OK | W_OK))
     {
-      a->debug("cannot access %s", devmem);
+      a->debug("cannot access %s: %s", devmem, strerror(errno));
       return 0;
     }