support for HW_SKIP_CONSOLE breaks use by blind people

Michal Suchanek hramrach at
Sat Jan 5 14:44:39 PST 2013

On 5 January 2013 23:04, Samuel Thibault <sthibault at> wrote:
> Michal Suchanek, le Sat 05 Jan 2013 22:47:20 +0100, a écrit :
>> > there is no VT switch, and pressing ^C 5s later kills the server (while
>> > we'd want ^C to just go to the server). The resulting Xorg.1.log is
>> > attached.
>> I don't think that an actual VT switch is required
> From the point of the user, it is. There is no reason why it should not
> happen just like with other video drivers in the use case at stake.

Those video drivers render graphics. The dummy driver does not. It's
not the same case.

>> It would be quite a few drivers to modify
> We can proceed just like video devices: only modify the void input
> driver into saying it doesn't need a VT, and the core then avoids
> allocating a VT only if *only* the dummy video driver and void input
> driver are used.

Indeed, you could possibly say that the dummy driver does not need
video output which then requires a VT switch and the void driver does
not need a tty input which would require locking the tty.

>> On x86 there is always the ACPI button but on some platforms nothing
>> like that is present so this flag would have to be set dynamically
>> when an input device is plugged in if set bu the input driver. Also
>> evdev handles keyboards and mice. Is plugging in a mouse enough to
>> warrant locking the tty? Is presence of synaptics or wacom device?
> I'm surprised that the discussion ends up with this way of thinking:
> shouldn't it be the converse, i.e. a VT is always allocated *except* if
> that is explicitly asked for by a special configuration? Otherwise we'll
> keep having users saying that their special use does not trigger a VT
> allocation...

But there is the problem. The dummy driver sets the flag because it
does not need the tty. The evdev driver does need the tty but it has
no flag to set because opening a tty is the default. The bug comes
exactly from the thinking that switching tty is the default and only
an exception to this rule is flagged. It would be much saner for the
driver to say that it needs the tty if and when it needs it.



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