Re: [PATCH] at_keyboard: Fix keyboards that report IBM PC AT scan codes

[Renaud Métrich]

Hello,

Please find an updated version of the patch proposing a fallback 
mechanism in case grub is not able to detect the set to be used.

I has been tested on the following systems:

- Lenovo P71

- Asus N53SN

- Dell Precision

- HP Elitebook

- Lenovo T460s

- QEMU/KVM

- HP G5430

On all these above, the fallback mechanism is not used at all, set is 
detected correctly.

However the mechanism is necessary for HP DL380p Gen 8 systems.

Renaud.

On 1/8/21 3:00 PM, Renaud Métrich wrote:
> Hello,
>
> It appears that the proposal works fine on all systems I could test 
> except one: a HP DL380p Gen 8.
>
> On that system, querying the set fails: the ACK bytes in write_mode(0) 
> work perfectly, but then 0xFE ("NACK") is read, as if the keyboard 
> didn't want to send back the set in use.
>
> Hence, query_mode() returns 0, causing set1 to be used, but 
> unfortunately the system expects set2 to be used.
>
> I tried using the "resend" command, but nothing helps.
>
> I'm hence proposing a fallback solution for this kind of hardware 
> where the admin can add a "at_keyboard_fallback_set" environment 
> variable in grub.cfg that would end using a specific set if 
> query_mode() fails.
>
> See proposed patch in attachment.
>
> Renaud.
>
> On 12/14/20 5:47 PM, Renaud Métrich wrote:
> > Hi Vladimir,
> >
> > Thanks for the hint, this was obvious now.
> >
> > Please find attached the new patch which definitely fixes the issue.
> >
> > It has been tested on various hardware (see git commit details).
> >
> > In a nutshell the solution is to stick to set 1 if controller is in 
> > Translate mode, and use set X otherwise, X being the queried mode.
> >
> > Additionally, in controller_fini, nothing has to be restored, since 
> > nothing was changed. This fixes an issue when switching between 
> > at_keyboard, console, and at_keyboard again, in case queried set is 
> > not the actual used set.
> >
> > Renaud.
> >
> > On 12/11/20 3:08 PM, Vladimir 'phcoder' Serbinenko wrote:
> > > On Fri, Dec 4, 2020 at 5:53 AM Renaud Métrich <rmetrich@redhat.com> 
> > > wrote:
> > > > Hi,
> > > >
> > > > Testing the proposed patch on my old Asus N53SN in Legacy failed: 
> > > > as soon as at_keyboard is selected, the keys are corrupted and it's 
> > > > impossible to do anything.
> > > >
> > > > Digging into this, it appears that query_mode() returns 2 (so set2 
> > > > needs to be used), but in fact internally the keycode are the ones 
> > > > expected by set1.
> > > This is because the patch doesn't take into account that controller is
> > > in "translate" mode.
> > > @Javier Martinez Canillas : Can you make your patch check whether
> > > KEYBOARD_AT_TRANSLATE is set ?
> > >
> > > _______________________________________________
> > > Grub-devel mailing list
> > > Grub-devel@gnu.org
> > > https://lists.gnu.org/mailman/listinfo/grub-devel

0001-at_keyboard-New-at_keyboard_fallback_set-environment.patch
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