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

From: Gustavo A. R. Silva
Date: Wed Mar 20 2019 - 15:41:41 EST




On 3/20/19 2:27 PM, Andrew Cooper wrote:
> On 20/03/2019 18:27, Gustavo A. R. Silva wrote:
>> 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 */
>
> Surely it would be better to transpose the #endif and its previous line,
> than to add a second fallthrough ?
>

I agree. The thing is that, currently, GCC is expecting to find the
fall-through "annotations" at the very bottom of the case statement,
as I mentioned it in the changelog text.

That's the reason why I decided to left in place the original comment.

Thanks
--
Gustavo