[Xen-devel] [PATCH] PCI: Mark expected switch fall-throughs

["Gustavo A. R. Silva" <gustavo@xxxxxxxxxxxxxx>]

In preparation to enabling -Wimplicit-fallthrough, mark switch
cases where we are expecting to fall through.

This patch fixes the following warnings:

drivers/pci/proc.c: In function ‘proc_bus_pci_ioctl’:
drivers/pci/proc.c:216:6: warning: this statement may fall through 
[-Wimplicit-fallthrough=]
   if (arch_can_pci_mmap_wc()) {
      ^
drivers/pci/proc.c:225:2: note: here
  default:
  ^~~~~~~

drivers/pci/xen-pcifront.c: In function ‘pcifront_backend_changed’:
drivers/pci/xen-pcifront.c:1105:6: warning: this statement may fall through 
[-Wimplicit-fallthrough=]
   if (xdev->state == XenbusStateClosed)
      ^
drivers/pci/xen-pcifront.c:1108:2: note: here
  case XenbusStateClosing:
  ^~~~

Notice that, in this particular case, the /* fall through */
comment is placed at the very bottom of the case statement,
which is what GCC is expecting to find.

Warning level 3 was used: -Wimplicit-fallthrough=3

This patch is part of the ongoing efforts to enable
-Wimplicit-fallthrough.

Signed-off-by: Gustavo A. R. Silva <gustavo@xxxxxxxxxxxxxx>
---
 drivers/pci/proc.c         | 1 +
 drivers/pci/xen-pcifront.c | 2 +-
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/proc.c b/drivers/pci/proc.c
index 6fa1627ce08d..445b51db75b0 100644
--- a/drivers/pci/proc.c
+++ b/drivers/pci/proc.c
@@ -222,6 +222,7 @@ static long proc_bus_pci_ioctl(struct file *file, unsigned 
int cmd,
                }
                /* If arch decided it can't, fall through... */
 #endif /* HAVE_PCI_MMAP */
+               /* fall through */
        default:
                ret = -EINVAL;
                break;
diff --git a/drivers/pci/xen-pcifront.c b/drivers/pci/xen-pcifront.c
index eba6e33147a2..14cf0f41ecf0 100644
--- a/drivers/pci/xen-pcifront.c
+++ b/drivers/pci/xen-pcifront.c
@@ -1104,7 +1104,7 @@ static void __ref pcifront_backend_changed(struct 
xenbus_device *xdev,
        case XenbusStateClosed:
                if (xdev->state == XenbusStateClosed)
                        break;
-               /* Missed the backend's CLOSING state -- fallthrough */
+               /* fall through - Missed the backend's CLOSING state. */
        case XenbusStateClosing:
                dev_warn(&xdev->dev, "backend going away!\n");
                pcifront_try_disconnect(pdev);
-- 
2.21.0


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