Re: [PATCH v1 1/2] tty/vt: Use KVAL instead of use bit operation

[Jiri Slaby]

On 19. 02. 25, 10:23, Alexey Gladkov wrote:
> On Wed, Feb 19, 2025 at 07:24:52AM +0100, Jiri Slaby wrote:
> > On 18. 02. 25, 13:29, Alexey Gladkov wrote:
> > > The K_HANDLERS always gets KVAL as an argument. It is better to use the
> > > KVAL macro itself instead of bit operation.
> > >
> > > Signed-off-by: Alexey Gladkov <legion@xxxxxxxxxx>
> > > ---
> > >    drivers/tty/vt/keyboard.c | 4 ++--
> > >    1 file changed, 2 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/drivers/tty/vt/keyboard.c b/drivers/tty/vt/keyboard.c
> > > index 804355da46f5..7df041ac4d5c 100644
> > > --- a/drivers/tty/vt/keyboard.c
> > > +++ b/drivers/tty/vt/keyboard.c
> > > @@ -885,7 +885,7 @@ static void k_shift(struct vc_data *vc, unsigned char value, char up_flag)
> > >    		if (kbd->kbdmode == VC_UNICODE)
> > >    			to_utf8(vc, npadch_value);
> > >    		else
> > > -			put_queue(vc, npadch_value & 0xff);
> > > +			put_queue(vc, KVAL(npadch_value));
> >
> > While the mask is the same, this is not a kval, right?
>
> I'm pretty sure it's KVAL, but to be honest I don't understand why it is
> not done for to_utf8() as well. All values passed to to_utf8() must be
> kval.

Not at all, it handles multibyte chars.

> We call to_utf8() in k_unicode, fn_enter (through k_spec), handle_diacr
> (through k_deadunicode or k_unicode). All K_HANDLERS take KVAL as value.

Yes, but pass unicode multibyte to to_utf8().

> If I understand this code correctly, it is more correct to write it like
> this:
>
> --- a/drivers/tty/vt/keyboard.c
> +++ b/drivers/tty/vt/keyboard.c
> @@ -882,10 +882,11 @@ static void k_shift(struct vc_data *vc, unsigned char value, char up_flag)
>
>          /* kludge */
>          if (up_flag && shift_state != old_state && npadch_active) {
> +               u32 kval = KVAL(npadch_value);
>                  if (kbd->kbdmode == VC_UNICODE)
> -                       to_utf8(vc, npadch_value);
> +                       to_utf8(vc, kval);

Definitely not, as you want to pass that multibyte char in.

--
js
suse labs