[U-Boot] [PATCH 3/8] usb_kdb: only process events succesfully received

[Michal Suchánek]

On Tue, 2 Jul 2019 15:11:07 +0200
Marek Vasut <marex at denx.de> wrote:

> On 7/2/19 3:04 PM, Michal Suchánek wrote:
> > On Tue, 2 Jul 2019 13:58:30 +0200
> > Marek Vasut <marex at denx.de> wrote:
> >   
> >> On 7/1/19 5:56 PM, Michal Suchanek wrote:  
> >>> Causes unbound key repeat on error otherwise.
> >>>
> >>> Signed-off-by: Michal Suchanek <msuchanek at suse.de>
> >>> ---
> >>>  common/usb_kbd.c | 7 +++----
> >>>  1 file changed, 3 insertions(+), 4 deletions(-)
> >>>
> >>> diff --git a/common/usb_kbd.c b/common/usb_kbd.c
> >>> index cc99c6be0720..948f9fd68490 100644
> >>> --- a/common/usb_kbd.c
> >>> +++ b/common/usb_kbd.c
> >>> @@ -339,10 +339,9 @@ static inline void usb_kbd_poll_for_event(struct usb_device *dev)
> >>>  	struct usb_kbd_pdata *data = dev->privptr;
> >>>  
> >>>  	/* Submit a interrupt transfer request */
> >>> -	usb_submit_int_msg(dev, data->intpipe, &data->new[0], data->intpktsize,
> >>> -			   data->intinterval);
> >>> -
> >>> -	usb_kbd_irq_worker(dev);
> >>> +	if (!usb_submit_int_msg(dev, data->intpipe, &data->new[0],    
> >>
> >> Shouldn't you propagate return value from this function ? It can return
> >> ENOTSUPP.
> >>  
> > 
> > If it did then probing keyboard would fail and we would not get here.  
> 
> So there is no chance this function could return an error here, ever ?
> E.g. what if it's implemented and someone yanks the keyboard cable out
> just at the right time ?

It returns errors all the time with dwc2. That's why we need to check
for the error condition. We should not get here if probing the keyboard
failed, though. So if the function is not supported we will not get
here. Anyway, if it's not supported or the keyboard is missing it by
definition cannot provide useful result so we should not process it.

Thanks

Michal