On 7/3/19 11:46 AM, Michal Suchánek wrote: > On Tue, 2 Jul 2019 23:20:28 +0200 > Marek Vasut <ma...@denx.de> wrote: > >> On 7/2/19 9:31 PM, Michal Suchánek wrote: >>> On Tue, 2 Jul 2019 20:38:27 +0200 >>> Marek Vasut <ma...@denx.de> wrote: >>> >>>> On 7/2/19 7:50 PM, Michal Suchánek wrote: >>>>> On Tue, 2 Jul 2019 18:58:54 +0200 >>>>> Marek Vasut <ma...@denx.de> wrote: >>>>> >>>>>> On 7/2/19 4:22 PM, Michal Suchánek wrote: >>>>>>> On Tue, 2 Jul 2019 15:11:07 +0200 >>>>>>> Marek Vasut <ma...@denx.de> wrote: >>>>>>> >>>>>>>> On 7/2/19 3:04 PM, Michal Suchánek wrote: >>>>>>>>> On Tue, 2 Jul 2019 13:58:30 +0200 >>>>>>>>> Marek Vasut <ma...@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 <msucha...@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. >>>>>>> >>>>>> >>>>>> Except you start ignoring the error value from e.g. malfunctioning >>>>>> keyboard here, instead of propagating it, correct ? >>>>> >>>>> It was never propagated to start with. The return value was not checked >>>>> at all. What I do here is check the return value and not process the >>>>> data on error whatever it contains (like the keypress returned last >>>>> time valid data was received). >>>> >>>> I can see a patch which checks usb_kbd_poll_for_event() return value. >>>> Can you add one ? >>> >>> What for? Apparently the keypress is processed in usb_kbd_irq_worker. >>> So checking the return value is needed to decide if the worker should >>> run, and is not particularly useful outside usb_kbd_poll_for_event. We >>> could signal a getc() failure but do we have any code handling getc() >>> failures? >> >> I presume getc() might signal EOF if the underlying hardware fails. >> But in general, it's a good practice to not ignore errors. >> > > It is not such a great idea. You might have multiple input hardware (ie > serial and usb keyboard). What does it mean that usb keyboard failed in > this context?
I'd say, the behavior is undefined ? > So in my view the ultimate consumer of getc() has no use for the error > so there is no point in propagating it. Ignoring errors and not reporting them isn't nice either, so what other option(s) do we have here ? _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de https://lists.denx.de/listinfo/u-boot
