1 files changed, 12 insertions, 8 deletions

diff --git a/include/linux/ssb/ssb.h b/include/linux/ssb/ssb.h
index 3d0a9ff24f01..24f988547361 100644
--- a/include/linux/ssb/ssb.h
+++ b/include/linux/ssb/ssb.h
@@ -269,7 +269,8 @@ struct ssb_bus {
 
         const struct ssb_bus_ops *ops;
 
-        /* The core in the basic address register window. (PCI bus only) */
+        /* The core currently mapped into the MMIO window.
+         * Not valid on all host-buses. So don't use outside of SSB. */
         struct ssb_device *mapped_device;
         union {
                 /* Currently mapped PCMCIA segment. (bustype == SSB_BUSTYPE_PCMCIA only) */
@@ -281,14 +282,17 @@ struct ssb_bus {
          * On PCMCIA-host busses this is used to protect the whole MMIO access. */
         spinlock_t bar_lock;
 
-        /* The bus this backplane is running on. */
+        /* The host-bus this backplane is running on. */
         enum ssb_bustype bustype;
-        /* Pointer to the PCI bus (only valid if bustype == SSB_BUSTYPE_PCI). */
-        struct pci_dev *host_pci;
-        /* Pointer to the PCMCIA device (only if bustype == SSB_BUSTYPE_PCMCIA). */
-        struct pcmcia_device *host_pcmcia;
-        /* Pointer to the SDIO device (only if bustype == SSB_BUSTYPE_SDIO). */
-        struct sdio_func *host_sdio;
+        /* Pointers to the host-bus. Check bustype before using any of these pointers. */
+        union {
+                /* Pointer to the PCI bus (only valid if bustype == SSB_BUSTYPE_PCI). */
+                struct pci_dev *host_pci;
+                /* Pointer to the PCMCIA device (only if bustype == SSB_BUSTYPE_PCMCIA). */
+                struct pcmcia_device *host_pcmcia;
+                /* Pointer to the SDIO device (only if bustype == SSB_BUSTYPE_SDIO). */
+                struct sdio_func *host_sdio;
+        };
 
         /* See enum ssb_quirks */
         unsigned int quirks;