On Tue, Nov 24, 2020 at 8:36 AM Kai-Heng Feng
<kai.heng.feng@xxxxxxxxxxxxx> wrote:
>
> Dell Precision 5550 fails to detect Thunderbolt device hotplug events,
> once the Thunderbolt device and its root port are runtime-suspended to
> D3cold.
>
> While putting the entire hierarchy to D3cold, the root port ACPI GPE is
> enabled via acpi_pci_propagate_wakeup() when suspending Thunderbolt
> bridges/switches. So when putting the root port to D3cold as last step,
> ACPI GPE is untouched as it's already enabled.
>
> However, platform may need PCI devices to be in D3hot or PME enabled
> prior enabling GPE to make it work.
What platforms and why.
> So re-enable ACPI GPE to address this.
>
> Signed-off-by: Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx>
> ---
> drivers/acpi/device_pm.c | 13 ++++++-------
> 1 file changed, 6 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/acpi/device_pm.c b/drivers/acpi/device_pm.c
> index 94d91c67aeae..dc25d9d204ae 100644
> --- a/drivers/acpi/device_pm.c
> +++ b/drivers/acpi/device_pm.c
> @@ -757,11 +757,10 @@ static int __acpi_device_wakeup_enable(struct acpi_device *adev,
>
> mutex_lock(&acpi_wakeup_lock);
>
> - if (wakeup->enable_count >= max_count)
> - goto out;
> -
> - if (wakeup->enable_count > 0)
> - goto inc;
> + if (wakeup->enable_count > 0) {
> + acpi_disable_gpe(wakeup->gpe_device, wakeup->gpe_number);
> + acpi_disable_wakeup_device_power(adev);
> + }
An event occurring at this point may be lost after this patch.
It looks like you are trying to work around a hardware issue. Can you
please describe that issue in detail?
>
> error = acpi_enable_wakeup_device_power(adev, target_state);
> if (error)
> @@ -777,8 +776,8 @@ static int __acpi_device_wakeup_enable(struct acpi_device *adev,
> acpi_handle_debug(adev->handle, "GPE%2X enabled for wakeup\n",
> (unsigned int)wakeup->gpe_number);
>
> -inc:
> - wakeup->enable_count++;
> + if (wakeup->enable_count < max_count)
> + wakeup->enable_count++;
>
> out:
> mutex_unlock(&acpi_wakeup_lock);
> --
> 2.29.2
>
