Re: [PATCH] platform/x86: intel-hid: Wake up Dell Latitude 7275 from suspend-to-idle

From: Rafael J. Wysocki
Date: Mon Jul 31 2017 - 17:54:40 EST


On Friday, July 28, 2017 02:06:36 AM Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
>
> On Dell Latitude 7275 the 5-button array is not exposed in the
> ACPI tables, but still notifies are sent to the Intel HID device
> object (device ID INT33D5) in response to power button actions while
> suspended to idle. However, they are currently ignored as the
> intel-hid driver is not prepared to take care of them.
>
> As a result, power button wakeup from suspend-to-idle doesn't work
> on this platform, but suspend-to-idle is the only reliable suspend
> variant on it (the S3 implementation in the platform firmware turns
> out to be broken), so it would be good to handle it properly.
>
> For this reason, add an upfront check against the power button press
> event (0xCE) to notify_handler() in the wakeup mode which allows it
> to catch the power button wakeup notification on the affected
> platform (even though priv->array is NULL on it) and should not
> change the behavior on platforms with priv->array present (because
> priv->array contains the event in question in those cases).
>
> Link: https://bugzilla.kernel.org/show_bug.cgi?id=196115
> Tested-by: Jérôme de Bretagne <jerome.debretagne@xxxxxxxxx>
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>

Please note that this change is requisite for

https://patchwork.kernel.org/patch/9873159/

so are there any objections or concerns?

> ---
> drivers/platform/x86/intel-hid.c | 17 ++++++++++++++---
> 1 file changed, 14 insertions(+), 3 deletions(-)
>
> Index: linux-pm/drivers/platform/x86/intel-hid.c
> ===================================================================
> --- linux-pm.orig/drivers/platform/x86/intel-hid.c
> +++ linux-pm/drivers/platform/x86/intel-hid.c
> @@ -203,15 +203,26 @@ static void notify_handler(acpi_handle h
> acpi_status status;
>
> if (priv->wakeup_mode) {
> + /*
> + * Needed for wakeup from suspend-to-idle to work on some
> + * platforms that don't expose the 5-button array, but still
> + * send notifies with the power button event code to this
> + * device object on power button actions while suspended.
> + */
> + if (event == 0xce)
> + goto wakeup;
> +
> /* Wake up on 5-button array events only. */
> if (event == 0xc0 || !priv->array)
> return;
>
> - if (sparse_keymap_entry_from_scancode(priv->array, event))
> - pm_wakeup_hard_event(&device->dev);
> - else
> + if (!sparse_keymap_entry_from_scancode(priv->array, event)) {
> dev_info(&device->dev, "unknown event 0x%x\n", event);
> + return;
> + }
>
> +wakeup:
> + pm_wakeup_hard_event(&device->dev);
> return;
> }
>
>