On 03/28/2013 11:34 AM, Richard GENOUD wrote:
> 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;
I think you want to remove that line too, so that p->state == NULL in
the error case, so that if the pinctrl_select_state_locked() call below
also fails to restore the old state, then (!old_state) will be true
inside the recursive call, so it doesn't recurse into itself forever.
> + if (old_state)
> + pinctrl_select_state_locked(p, NULL);
You want to pass old_state rather than NULL there, I think.
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