Re: [PATCH v2 3/3] cros_ec: Don't signal wake event for non-wake host events

[Lee Jones <lee.jones@linaro.org>]

On Tue, 14 Feb 2017, Thierry Escande wrote:

> From: Shawn Nematbakhsh <shawnn@chromium.org>
> 
> The subset of wake-enabled host events is defined by the EC, but the EC
> may still send non-wake host events if we're in the process of
> suspending. Get the mask of wake-enabled host events from the EC and
> filter out non-wake events to prevent spurious aborted suspend
> attempts.
> 
> Signed-off-by: Shawn Nematbakhsh <shawnn@chromium.org>
> Signed-off-by: Thierry Escande <thierry.escande@collabora.com>
> ---
>  drivers/mfd/cros_ec.c                   | 13 ++++--
>  drivers/platform/chrome/cros_ec_proto.c | 76 ++++++++++++++++++++++++++++++---
>  include/linux/mfd/cros_ec.h             |  5 ++-
>  3 files changed, 85 insertions(+), 9 deletions(-)

Looks okay from an MFD perspective:

For my own reference:
  Acked-for-MFD-by: Lee Jones <lee.jones@linaro.org>

> diff --git a/drivers/mfd/cros_ec.c b/drivers/mfd/cros_ec.c
> index 9b66a98..1bcb502 100644
> --- a/drivers/mfd/cros_ec.c
> +++ b/drivers/mfd/cros_ec.c
> @@ -54,12 +54,19 @@ static const struct mfd_cell ec_pd_cell = {
>  static irqreturn_t ec_irq_thread(int irq, void *data)
>  {
>  	struct cros_ec_device *ec_dev = data;
> +	bool wake_event = true;
>  	int ret;
>  
> -	if (device_may_wakeup(ec_dev->dev))
> +	ret = cros_ec_get_next_event(ec_dev, &wake_event);
> +
> +	/*
> +	 * Signal only if wake host events or any interrupt if
> +	 * cros_ec_get_next_event() returned an error (default value for
> +	 * wake_event is true)
> +	 */
> +	if (wake_event && device_may_wakeup(ec_dev->dev))
>  		pm_wakeup_event(ec_dev->dev, 0);
>  
> -	ret = cros_ec_get_next_event(ec_dev);
>  	if (ret > 0)
>  		blocking_notifier_call_chain(&ec_dev->event_notifier,
>  					     0, ec_dev);
> @@ -212,7 +219,7 @@ EXPORT_SYMBOL(cros_ec_suspend);
>  
>  static void cros_ec_drain_events(struct cros_ec_device *ec_dev)
>  {
> -	while (cros_ec_get_next_event(ec_dev) > 0)
> +	while (cros_ec_get_next_event(ec_dev, NULL) > 0)
>  		blocking_notifier_call_chain(&ec_dev->event_notifier,
>  					     1, ec_dev);
>  }
> diff --git a/drivers/platform/chrome/cros_ec_proto.c b/drivers/platform/chrome/cros_ec_proto.c
> index d6942a6..8dfa7fc 100644
> --- a/drivers/platform/chrome/cros_ec_proto.c
> +++ b/drivers/platform/chrome/cros_ec_proto.c
> @@ -150,6 +150,40 @@ int cros_ec_check_result(struct cros_ec_device *ec_dev,
>  }
>  EXPORT_SYMBOL(cros_ec_check_result);
>  
> +/*
> + * cros_ec_get_host_event_wake_mask
> + *
> + * Get the mask of host events that cause wake from suspend.
> + *
> + * @ec_dev: EC device to call
> + * @msg: message structure to use
> + * @mask: result when function returns >=0.
> + *
> + * LOCKING:
> + * the caller has ec_dev->lock mutex, or the caller knows there is
> + * no other command in progress.
> + */
> +static int cros_ec_get_host_event_wake_mask(struct cros_ec_device *ec_dev,
> +					    struct cros_ec_command *msg,
> +					    uint32_t *mask)
> +{
> +	struct ec_response_host_event_mask *r;
> +	int ret;
> +
> +	msg->command = EC_CMD_HOST_EVENT_GET_WAKE_MASK;
> +	msg->version = 0;
> +	msg->outsize = 0;
> +	msg->insize = sizeof(*r);
> +
> +	ret = send_command(ec_dev, msg);
> +	if (ret > 0) {
> +		r = (struct ec_response_host_event_mask *)msg->data;
> +		*mask = r->mask;
> +	}
> +
> +	return ret;
> +}
> +
>  static int cros_ec_host_command_proto_query(struct cros_ec_device *ec_dev,
>  					    int devidx,
>  					    struct cros_ec_command *msg)
> @@ -387,6 +421,15 @@ int cros_ec_query_all(struct cros_ec_device *ec_dev)
>  	else
>  		ec_dev->mkbp_event_supported = 1;
>  
> +	/*
> +	 * Get host event wake mask, assume all events are wake events
> +	 * if unavailable.
> +	 */
> +	ret = cros_ec_get_host_event_wake_mask(ec_dev, proto_msg,
> +					       &ec_dev->host_event_wake_mask);
> +	if (ret < 0)
> +		ec_dev->host_event_wake_mask = U32_MAX;
> +
>  	ret = 0;
>  
>  exit:
> @@ -504,12 +547,35 @@ static int get_keyboard_state_event(struct cros_ec_device *ec_dev)
>  	return ec_dev->event_size;
>  }
>  
> -int cros_ec_get_next_event(struct cros_ec_device *ec_dev)
> +int cros_ec_get_next_event(struct cros_ec_device *ec_dev, bool *wake_event)
>  {
> -	if (ec_dev->mkbp_event_supported)
> -		return get_next_event(ec_dev);
> -	else
> -		return get_keyboard_state_event(ec_dev);
> +	u32 host_event;
> +	int ret;
> +
> +	if (!ec_dev->mkbp_event_supported) {
> +		ret = get_keyboard_state_event(ec_dev);
> +		if (ret < 0)
> +			return ret;
> +
> +		if (wake_event)
> +			*wake_event = true;
> +
> +		return ret;
> +	}
> +
> +	ret = get_next_event(ec_dev);
> +	if (ret < 0)
> +		return ret;
> +
> +	if (wake_event) {
> +		host_event = cros_ec_get_host_event(ec_dev);
> +
> +		/* Consider non-host_event as wake event */
> +		*wake_event = !host_event ||
> +			      !!(host_event & ec_dev->host_event_wake_mask);
> +	}
> +
> +	return ret;
>  }
>  EXPORT_SYMBOL(cros_ec_get_next_event);
>  
> diff --git a/include/linux/mfd/cros_ec.h b/include/linux/mfd/cros_ec.h
> index 2ceb245..bb85325 100644
> --- a/include/linux/mfd/cros_ec.h
> +++ b/include/linux/mfd/cros_ec.h
> @@ -148,6 +148,7 @@ struct cros_ec_device {
>  
>  	struct ec_response_get_next_event event_data;
>  	int event_size;
> +	u32 host_event_wake_mask;
>  };
>  
>  /**
> @@ -294,10 +295,12 @@ int cros_ec_query_all(struct cros_ec_device *ec_dev);
>   * cros_ec_get_next_event -  Fetch next event from the ChromeOS EC
>   *
>   * @ec_dev: Device to fetch event from
> + * @wake_event: Pointer to a bool set to true upon return if the event might be
> + *              treated as a wake event. Ignored if null.
>   *
>   * Returns: 0 on success, Linux error number on failure
>   */
> -int cros_ec_get_next_event(struct cros_ec_device *ec_dev);
> +int cros_ec_get_next_event(struct cros_ec_device *ec_dev, bool *wake_event);
>  
>  /**
>   * cros_ec_get_host_event - Return a mask of event set by the EC.

-- 
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog