MIME-Version: 1.0
References: <20230313144710.3516-1-simon@invisiblethingslab.com>
In-Reply-To: <20230313144710.3516-1-simon@invisiblethingslab.com>
From:   "Rafael J. Wysocki" <rafael@kernel.org>
Date:   Mon, 20 Mar 2023 18:32:02 +0100
Message-ID: <CAJZ5v0idjCBRWU2SuOmoVgR847zNisPX65dqycoHdEO0W+C9zA@mail.gmail.com>
Subject: Re: [PATCH v2] ACPI: s2idle: Log when enabling wakeup IRQ fails
To:     Simon Gaiser <simon@invisiblethingslab.com>
Cc:     "Rafael J . Wysocki" <rafael@kernel.org>,
        Len Brown <lenb@kernel.org>, linux-acpi@vger.kernel.org,
        linux-kernel@vger.kernel.org
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: 8BIT
Precedence: bulk

On Mon, Mar 13, 2023 at 3:47 PM Simon Gaiser
<simon@invisiblethingslab.com> wrote:
>
> enable_irq_wake() can fail. Previously acpi_s2idle_prepare() silently
> ignored it's return code. Based on [1] we should try to continue even in
> case of an error, so just log a warning for now.
>
> Discovered when trying to go into s2idle under Xen. This leads to a
> system that can't be woken, since xen-pirq currently doesn't support
> setting wakeup IRQs [2]. With this you get at least some helpful log
> message if you have access to console messages.
>
> Link: https://lore.kernel.org/linux-acpi/20230313125344.2893-1-simon@invisiblethingslab.com/ # v1
> Link: https://lore.kernel.org/linux-acpi/CAJZ5v0jahjt58nP6P5+xRdtD_ndYPvq4ecMVz6nfGu9tf5iaUw@mail.gmail.com/ # [1]
> Link: https://lore.kernel.org/xen-devel/20230313134102.3157-1-simon@invisiblethingslab.com/ # [2]
> Signed-off-by: Simon Gaiser <simon@invisiblethingslab.com>
> ---
> v2:
>  - Based on feedback switched to only logging a warning instead of
>    returning an error.
> ---
>  drivers/acpi/sleep.c | 8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/acpi/sleep.c b/drivers/acpi/sleep.c
> index 4ca667251272..6b30dea94fae 100644
> --- a/drivers/acpi/sleep.c
> +++ b/drivers/acpi/sleep.c
> @@ -714,7 +714,13 @@ int acpi_s2idle_begin(void)
>  int acpi_s2idle_prepare(void)
>  {
>         if (acpi_sci_irq_valid()) {
> -               enable_irq_wake(acpi_sci_irq);
> +               int error;
> +
> +               error = enable_irq_wake(acpi_sci_irq);
> +               if (error)
> +                       pr_warn("Warning: Failed to enable wakeup from IRQ %d: %d\n",
> +                               acpi_sci_irq,
> +                               error);
>                 acpi_ec_set_gpe_wake_mask(ACPI_GPE_ENABLE);
>         }
>
> --

Applied (with a minor white space adjustment) as 6.4 material, thanks!