On [mer., 27.03.2013 17:55:45], Stephen Warren wrote:
> On 03/25/2013 08:47 AM, Richard Genoud wrote:
> > If a new state is applied, the groups configured in the old state but
> > not in the new state are disabled.
> > If something goes wrong and the new state can't be applied, we have to
> > re-enable those groups.
>
> What is the use-case for this? I wonder if it isn't better to simply
> undo the partial selection of the new state (as patch 3/4 attempts to
> do) and then leave p->state==NULL, indicating that no state is actively
> selected. IIRC, this would be the same as right after the initial
> pinctrl_select().
>
> I wonder if it's likely that attempting to re-apply the old state would
> actually work, given that applying something just failed.
>
> Finally, this recovery code doesn't:
>
> a) Process anything except MUX_GROUP; any pin config settings in the old
> state aren't restored.
>
> b) (I think) Apply any mux settings that don't involve groups that are
> referenced by both the old and new states; given that patch 3/4 attempts
> to undo everything in the failed application of the new state, I think
> this "re-apply the old state" code should simple run through everything
> in the old state any apply it unconditionally.
So, if I understand correctly, it could be as simple as that:
}
- if (old_state) {
- list_for_each_entry(setting, &old_state->settings, node) {
- bool found = false;
- if (setting->type != PIN_MAP_TYPE_MUX_GROUP)
- continue;
- list_for_each_entry(setting2, &state->settings, node) {
- if (setting2->type != PIN_MAP_TYPE_MUX_GROUP)
- continue;
- if (setting2->data.mux.group ==
- setting->data.mux.group) {
- found = true;
- break;
- }
- }
- if (!found)
- pinmux_enable_setting(setting);
- }
- }
-
p->state = old_state;
+
+ if (old_state)
+ pinctrl_select_state_locked(p, NULL);
+
return ret;
}
>
> c) Set p->state = oldstate, so it's left at NULL, which would confuse
> any future pinctrl_select().
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