Re: [DISCUSSION] Weston-Init and non-root weston

[Denys Dmytriyenko <denis@denix.org>]

On Mon, Apr 17, 2023 at 06:16:19PM -0500, Randolph Sapp wrote:
> On 4/17/23 18:08, Andrew Davis wrote:
> >On 4/17/23 6:01 PM, Randolph Sapp wrote:
> >>On 4/17/23 17:52, Andrew Davis wrote:
> >>>On 4/17/23 5:43 PM, Randolph Sapp wrote:
> >>>>On 4/17/23 17:39, Andrew Davis wrote:
> >>>>>On 4/17/23 5:32 PM, Randolph Sapp wrote:
> >>>>>>Finally getting around to weston-init issue I
> >>>>>>highlighted a while back and there's only one real issue
> >>>>>>preventing us from reusing the base weston-init recipe
> >>>>>>-- our touchscreen auto-configuration script.
> >>>>>>
> >>>>>>That script has to have root access to setup and reload
> >>>>>>udev rules and as we know setuid won't work for shell
> >>>>>>scripts.
> >>>>>>
> >>>>>>I propose we rewrite it in something that can use setuid
> >>>>>>(perl or c or something of the sort). I'm currently
> >>>>>>looking at perl as there's already quite a few core
> >>>>>>recipes that rdepend on it.
> >>>>>>
> >>>>>>Then we just need to inject it into the runWeston script
> >>>>>>and adjust the two init scripts to point at that.
> >>>>>>
> >>>>>>Any concerns or objections?
> >>>>>
> >>>>>Why not just drop out that old touchscreen script, it is a
> >>>>>non-standard way of doing
> >>>>>this task and should be removed.
> >>>>>
> >>>>>Andrew
> >>>>
> >>>>It's non-standard, but that's because there really isn't a
> >>>>good standard for calibrating touch screens under Weston.
> >>>>AFAIK this is still useful.
> >>>
> >>>https://wiki.st.com/stm32mpu/wiki/How_to_calibrate_the_touchscreen
> >>>
> >>>This seems like the standard ^^
> >>>
> >>>Andrew
> >>
> >>That does save the config for the user running weston. Currently
> >>our script saves and loads the config for all users. This could
> >>technically be seen as a regression, but it doesn't seem that
> >>bad to me.
> >
> >Better question than does it provide "any benefit at all": Does the
> >benefit outweigh the hacky-ness and effort needed to maintain
> >and document it?..
> >
> >Andrew
> 
> I would say no, it doesn't outweigh the hacky-ness. Our script
> force-reloads Weston adding an unnecessary delay for every
> recalibration.
> 
> Denys, any input here? Anyone you know of expecting this behavior
> downstream?

There's always a balance between doing things generically and making things 
very user friendly. Finding such balance is not easy - the pendulum has been 
swinging back and forth through the years...

This was one of the earliest out-of-box user experience additions to TI 
SDKs and has been relied upon by downstream products. I don't have strong 
objections for removing this custom code, but you might want to check with 
the corresponding product SDK teams.

-- 
Denys