Messages in this thread | | | Subject | Re: [PATCH 1/5] ACPI: battery: Do not unload battery hooks on single error | From | Armin Wolf <> | Date | Mon, 19 Sep 2022 22:35:33 +0200 |
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Am 19.09.22 um 21:12 schrieb Armin Wolf:
> Am 19.09.22 um 18:27 schrieb Rafael J. Wysocki: > >> On Mon, Sep 19, 2022 at 12:42 PM Hans de Goede <hdegoede@redhat.com> >> wrote: >>> Hi, >>> >>> On 9/12/22 13:53, Armin Wolf wrote: >>>> Currently, battery hooks are being unloaded if they return >>>> an error when adding a single battery. >>>> This however also causes the removal of successfully added >>>> hooks if they return -ENODEV for a single unsupported >>>> battery. >>>> >>>> Do not unload battery hooks in such cases since the hook >>>> handles any cleanup actions. >>>> >>>> Signed-off-by: Armin Wolf <W_Armin@gmx.de> >>> Maybe instead of removing all error checking, allow -ENODEV >>> and behave as before when the error is not -ENODEV ? >>> >>> Otherwise we should probably make the add / remove callbacks >>> void to indicate that any errors are ignored. >>> >>> Rafael, do you have any opinion on this? >> IMV this is not a completely safe change, because things may simply >> not work in the cases in which an error is returned. >> >> It would be somewhat better to use a special error code to indicate >> "no support" (eg. -ENOTSUPP) and ignore that one only. > > I would favor -ENODEV then, since it is already used by quiet a few > drivers > to indicate a unsupported battery. > > Armin Wolf > While checking all instances where the battery hook mechanism is currently used, i found out that all but a single battery hook return -ENODEV for all errors they encounter, the exception being the huawei-wmi driver.
I do not know the reason for this, but i fear unloading the extension on for example -ENOTSUP will result in similar behavior by hooks wanting to avoid being unloaded on harmless errors.
However, i agree that when ignoring all errors, battery extensions which provide similar attributes may currently delete each others attributes.
Any idea on how to solve this?
Armin Wolf
>>>> --- >>>> drivers/acpi/battery.c | 24 +++--------------------- >>>> 1 file changed, 3 insertions(+), 21 deletions(-) >>>> >>>> diff --git a/drivers/acpi/battery.c b/drivers/acpi/battery.c >>>> index 306513fec1e1..e59c261c7c59 100644 >>>> --- a/drivers/acpi/battery.c >>>> +++ b/drivers/acpi/battery.c >>>> @@ -724,20 +724,10 @@ void battery_hook_register(struct >>>> acpi_battery_hook *hook) >>>> * its attributes. >>>> */ >>>> list_for_each_entry(battery, &acpi_battery_list, list) { >>>> - if (hook->add_battery(battery->bat)) { >>>> - /* >>>> - * If a add-battery returns non-zero, >>>> - * the registration of the extension has failed, >>>> - * and we will not add it to the list of loaded >>>> - * hooks. >>>> - */ >>>> - pr_err("extension failed to load: %s", >>>> hook->name); >>>> - __battery_hook_unregister(hook, 0); >>>> - goto end; >>>> - } >>>> + hook->add_battery(battery->bat); >>>> } >>>> pr_info("new extension: %s\n", hook->name); >>>> -end: >>>> + >>>> mutex_unlock(&hook_mutex); >>>> } >>>> EXPORT_SYMBOL_GPL(battery_hook_register); >>>> @@ -762,15 +752,7 @@ static void battery_hook_add_battery(struct >>>> acpi_battery *battery) >>>> * during the battery module initialization. >>>> */ >>>> list_for_each_entry_safe(hook_node, tmp, &battery_hook_list, >>>> list) { >>>> - if (hook_node->add_battery(battery->bat)) { >>>> - /* >>>> - * The notification of the extensions has >>>> failed, to >>>> - * prevent further errors we will unload the >>>> extension. >>>> - */ >>>> - pr_err("error in extension, unloading: %s", >>>> - hook_node->name); >>>> - __battery_hook_unregister(hook_node, 0); >>>> - } >>>> + hook_node->add_battery(battery->bat); >>>> } >>>> mutex_unlock(&hook_mutex); >>>> } >>>> -- >>>> 2.30.2 >>>>
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