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Date: Mon, 13 Feb 2017 13:42:11 +0100
From: Thierry Escande <thierry.escande@...labora.com>
To: Lee Jones <lee.jones@...aro.org>
Cc: Benson Leung <bleung@...omium.org>, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 3/3] cros_ec: Don't signal wake event for non-wake host
events
Hi Lee,
On 07/02/2017 17:12, Lee Jones wrote:
> On Wed, 25 Jan 2017, Thierry Escande wrote:
>
>> From: Shawn Nematbakhsh <shawnn@...omium.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@...omium.org>
>> Signed-off-by: Thierry Escande <thierry.escande@...labora.com>
>> ---
>> drivers/mfd/cros_ec.c | 14 ++++++--
>> drivers/platform/chrome/cros_ec_proto.c | 60 +++++++++++++++++++++++++++++++++
>> include/linux/mfd/cros_ec.h | 12 +++++++
>> 3 files changed, 84 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/mfd/cros_ec.c b/drivers/mfd/cros_ec.c
>> index abd8342..510dfbb 100644
>> --- a/drivers/mfd/cros_ec.c
>> +++ b/drivers/mfd/cros_ec.c
>> @@ -53,12 +53,22 @@ 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;
>> + u8 wake_event = 1;
>
> Bool, true?
Ok.
>
>> + u32 host_event;
>> int ret;
>>
>> - if (device_may_wakeup(ec_dev->dev))
>> + ret = cros_ec_get_next_event(ec_dev);
>
> What does (ret == 0) mean?
The get_next_event() API called from cros_ec_get_next_event() only sets
event_data in the ec_dev structure if the command has actually been
sent. So (ret == 0) is not treated as an error and is silently ignored.
In this case, the interrupt is treated as a wake event.
>
> ... and is is possible for (ret < 0)?
>
>> + if (ret > 0 && ec_dev->mkbp_event_supported) {
>
> cros_ec_get_host_event() checks for (ec_dev->mkbp_event_supported)
> anyway, so you can drop it here no?
Sure but we only need to call cros_ec_get_host_event() if
mkbp_event_supported is true. Anyway, I'll move the host_event check
with cros_ec_get_host_event() into cros_ec_get_next_event() to avoid
this double check.
>
>> + /* Don't signal wake event for non-wake host events */
>> + host_event = cros_ec_get_host_event(ec_dev);
>> + if (host_event && !(host_event & ec_dev->host_event_wake_mask))
>> + wake_event = 0;
>
> false
Will do.
Thanks,
Thierry
>
>> + }
>> +
>> + 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);
>> diff --git a/drivers/platform/chrome/cros_ec_proto.c b/drivers/platform/chrome/cros_ec_proto.c
>> index 256249b..a216a32 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:
>> @@ -507,3 +550,20 @@ int cros_ec_get_next_event(struct cros_ec_device *ec_dev)
>> return get_keyboard_state_event(ec_dev);
>> }
>> EXPORT_SYMBOL(cros_ec_get_next_event);
>> +
>> +u32 cros_ec_get_host_event(struct cros_ec_device *ec_dev)
>> +{
>> + if (WARN_ON(!ec_dev->mkbp_event_supported))
>> + return 0;
>> +
>> + if (ec_dev->event_data.event_type != EC_MKBP_EVENT_HOST_EVENT)
>> + return 0;
>> +
>> + if (ec_dev->event_size != sizeof(u32)) {
>> + dev_warn(ec_dev->dev, "Invalid host event size\n");
>> + return 0;
>> + }
>> +
>> + return get_unaligned_le32(&ec_dev->event_data.data.host_event);
>> +}
>> +EXPORT_SYMBOL(cros_ec_get_host_event);
>> diff --git a/include/linux/mfd/cros_ec.h b/include/linux/mfd/cros_ec.h
>> index f62043a..8f37c4e 100644
>> --- a/include/linux/mfd/cros_ec.h
>> +++ b/include/linux/mfd/cros_ec.h
>> @@ -146,6 +146,7 @@ struct cros_ec_device {
>>
>> struct ec_response_get_next_event event_data;
>> int event_size;
>> + u32 host_event_wake_mask;
>> };
>>
>> /**
>> @@ -297,6 +298,17 @@ int cros_ec_query_all(struct cros_ec_device *ec_dev);
>> */
>> int cros_ec_get_next_event(struct cros_ec_device *ec_dev);
>>
>> +/**
>> + * cros_ec_get_host_event - Return a mask of event set by the EC.
>> + *
>> + * Once cros_ec_get_next_event() has been called, if the event source is
>> + * a host event, this function returns the precise event that triggered
>> + * the interrupt.
>> + *
>> + * This function is a helper to know which events are raised.
>> + */
>> +u32 cros_ec_get_host_event(struct cros_ec_device *ec_dev);
>> +
>> /* sysfs stuff */
>> extern struct attribute_group cros_ec_attr_group;
>> extern struct attribute_group cros_ec_lightbar_attr_group;
>
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