On 4/29/19 9:44 AM, David Laight wrote:
> From: Gustavo A. R. Silva
>> Sent: 29 April 2019 15:40
>> In preparation to enabling -Wimplicit-fallthrough, mark switch
>> cases where we are expecting to fall through.
> ...
>> diff --git a/drivers/usb/usbip/vhci_hcd.c b/drivers/usb/usbip/vhci_hcd.c
>> index 667d9c0ec905..000ab7225717 100644
>> --- a/drivers/usb/usbip/vhci_hcd.c
>> +++ b/drivers/usb/usbip/vhci_hcd.c
>> @@ -508,6 +508,7 @@ static int vhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
>> case USB_PORT_FEAT_U1_TIMEOUT:
>> usbip_dbg_vhci_rh(
>> " SetPortFeature: USB_PORT_FEAT_U1_TIMEOUT\n");
>> + /* Fall through */
>> case USB_PORT_FEAT_U2_TIMEOUT:
>> usbip_dbg_vhci_rh(
>> " SetPortFeature: USB_PORT_FEAT_U2_TIMEOUT\n");
>
> That doesn't look right, both debug messages seem to get printed.
>
At first sight, I thought the same way, then I took a look into
commit:
1c9de5bf428612458427943b724bea51abde520a
and noticed that the original developer properly added fall-through
comments in other places in the same switch() code, that gave me the
impression he knew what he was doing; then I noticed the following
error message in case USB_PORT_FEAT_U2_TIMEOUT:
if (hcd->speed != HCD_USB3) {
pr_err("USB_PORT_FEAT_U1/2_TIMEOUT req not "
"supported for USB 2.0 roothub\n");
goto error;
}
this error message is what makes me think the fall-through is
intentional; otherwise I think it would look like this instead:
if (hcd->speed != HCD_USB3) {
pr_err("USB_PORT_FEAT_U2_TIMEOUT req not "
"supported for USB 2.0 roothub\n");
goto error;
}
Thanks
--
Gustavo
