Re: [PATCH v4 06/17] platform: chrome: cros_ec: handle MKBP more events flag

Enric Balletbo i Serra
2019-11-11T09:31:06Z

On 10/11/19 13:28, Jonathan Cameron wrote:
> On Tue, 5 Nov 2019 14:26:41 -0800
> Gwendal Grignou <gwendal@chromium.org> wrote:
>
>> From: Enrico Granata <egranata@chromium.org>
>>
>> The ChromeOS EC has support for signaling to the host that
>> a single IRQ can serve multiple MKBP (Matrix KeyBoard Protocol)
>> events.
>>
>> Doing this serves an optimization purpose, as it minimizes the
>> number of round-trips into the interrupt handling machinery, and
>> it proves beneficial to sensor timestamping as it keeps the desired
>> synchronization of event times between the two processors.
>>
>> This patch adds kernel support for this EC feature, allowing the
>> ec_irq to loop until all events have been served.
>>
>> Signed-off-by: Enrico Granata <egranata@chromium.org>
>> Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
> A couple of trivial things inline.
> I just checked with the script and it doesn't seem to warn on the ()
> but the documentation for kernel-doc suggests it should be there...
>
> I guess things are more relaxed than I though.. Fix them if you are
> doing another spin perhaps but don't bother otherwise.
>
> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
>

Looks good to me, please fix the above comments and:

Acked-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>

Thanks,
Enric

>> ---
>> Changes in v4:
>> - Check patch with --strict option
>> Alignement
>> Changes in v3:
>> Fix indentation.
>> Changes in v2:
>> Process flag inside cros_ec_get_next_event, clean flag from event.
>> Introduce public function cros_ec_handle_event(), use it in rpmsg and
>> ishtp transport layer.
>> Remplace dev_info with dev_dbg, call only once.
>>
>> drivers/platform/chrome/cros_ec.c | 34 +++++++--
>> drivers/platform/chrome/cros_ec_ishtp.c | 8 +-
>> drivers/platform/chrome/cros_ec_lpc.c | 15 +++-
>> drivers/platform/chrome/cros_ec_proto.c | 81 +++++++++++++--------
>> drivers/platform/chrome/cros_ec_rpmsg.c | 19 +----
>> include/linux/platform_data/cros_ec_proto.h | 12 ++-
>> 6 files changed, 107 insertions(+), 62 deletions(-)
>>
>> diff --git a/drivers/platform/chrome/cros_ec.c b/drivers/platform/chrome/cros_ec.c
>> index d3dfa27171e6..c9f0b9ebcbc1 100644
>> --- a/drivers/platform/chrome/cros_ec.c
>> +++ b/drivers/platform/chrome/cros_ec.c
>> @@ -40,13 +40,23 @@ static irqreturn_t ec_irq_handler(int irq, void *data)
>> return IRQ_WAKE_THREAD;
>> }
>>
>> -static irqreturn_t ec_irq_thread(int irq, void *data)
>> +/**
>> + * cros_ec_handle_event - process and forward pending events on EC
>
> cros_ec_handle_event() -
>
>> + * @ec_dev: Device with events to process.
>> + *
>> + * Call this function in a loop when the kernel is notified that the EC has
>> + * pending events.
>> + *
>> + * Return: true if more events are still pending and this function should be
>> + * called again.
>> + */
>> +bool cros_ec_handle_event(struct cros_ec_device *ec_dev)
>> {
>> - struct cros_ec_device *ec_dev = data;
>> - bool wake_event = true;
>> + bool wake_event;
>> + bool ec_has_more_events;
>> int ret;
>>
>> - ret = cros_ec_get_next_event(ec_dev, &wake_event);
>> + ret = cros_ec_get_next_event(ec_dev, &wake_event, &ec_has_more_events);
>>
>> /*
>> * Signal only if wake host events or any interrupt if
>> @@ -59,6 +69,20 @@ static irqreturn_t ec_irq_thread(int irq, void *data)
>> if (ret > 0)
>> blocking_notifier_call_chain(&ec_dev->event_notifier,
>> 0, ec_dev);
>> +
>> + return ec_has_more_events;
>> +}
>> +EXPORT_SYMBOL(cros_ec_handle_event);
>> +
>> +static irqreturn_t ec_irq_thread(int irq, void *data)
>> +{
>> + struct cros_ec_device *ec_dev = data;
>> + bool ec_has_more_events;
>> +
>> + do {
>> + ec_has_more_events = cros_ec_handle_event(ec_dev);
>> + } while (ec_has_more_events);
>> +
>> return IRQ_HANDLED;
>> }
>>
>> @@ -274,7 +298,7 @@ EXPORT_SYMBOL(cros_ec_suspend);
>> static void cros_ec_report_events_during_suspend(struct cros_ec_device *ec_dev)
>> {
>> while (ec_dev->mkbp_event_supported &&
>> - cros_ec_get_next_event(ec_dev, NULL) > 0)
>> + cros_ec_get_next_event(ec_dev, NULL, NULL) > 0)
>> blocking_notifier_call_chain(&ec_dev->event_notifier,
>> 1, ec_dev);
>> }
>> diff --git a/drivers/platform/chrome/cros_ec_ishtp.c b/drivers/platform/chrome/cros_ec_ishtp.c
>> index 5c848f22b44b..e5996821d08b 100644
>> --- a/drivers/platform/chrome/cros_ec_ishtp.c
>> +++ b/drivers/platform/chrome/cros_ec_ishtp.c
>> @@ -136,11 +136,11 @@ static void ish_evt_handler(struct work_struct *work)
>> struct ishtp_cl_data *client_data =
>> container_of(work, struct ishtp_cl_data, work_ec_evt);
>> struct cros_ec_device *ec_dev = client_data->ec_dev;
>> + bool ec_has_more_events;
>>
>> - if (cros_ec_get_next_event(ec_dev, NULL) > 0) {
>> - blocking_notifier_call_chain(&ec_dev->event_notifier,
>> - 0, ec_dev);
>> - }
>> + do {
>> + ec_has_more_events = cros_ec_handle_event(ec_dev);
>> + } while (ec_has_more_events);
>> }
>>
>> /**
>> diff --git a/drivers/platform/chrome/cros_ec_lpc.c b/drivers/platform/chrome/cros_ec_lpc.c
>> index 3c77496e164d..dccf479c6625 100644
>> --- a/drivers/platform/chrome/cros_ec_lpc.c
>> +++ b/drivers/platform/chrome/cros_ec_lpc.c
>> @@ -312,13 +312,20 @@ static int cros_ec_lpc_readmem(struct cros_ec_device *ec, unsigned int offset,
>> static void cros_ec_lpc_acpi_notify(acpi_handle device, u32 value, void *data)
>> {
>> struct cros_ec_device *ec_dev = data;
>> + bool ec_has_more_events;
>> + int ret;
>>
>> ec_dev->last_event_time = cros_ec_get_time_ns();
>>
>> - if (ec_dev->mkbp_event_supported &&
>> - cros_ec_get_next_event(ec_dev, NULL) > 0)
>> - blocking_notifier_call_chain(&ec_dev->event_notifier, 0,
>> - ec_dev);
>> + if (ec_dev->mkbp_event_supported)
>> + do {
>> + ret = cros_ec_get_next_event(ec_dev, NULL,
>> + &ec_has_more_events);
>> + if (ret > 0)
>> + blocking_notifier_call_chain(
>> + &ec_dev->event_notifier, 0,
>> + ec_dev);
>> + } while (ec_has_more_events);
>>
>> if (value == ACPI_NOTIFY_DEVICE_WAKE)
>> pm_system_wakeup();
>> diff --git a/drivers/platform/chrome/cros_ec_proto.c b/drivers/platform/chrome/cros_ec_proto.c
>> index b502933e911b..03173ca66b1b 100644
>> --- a/drivers/platform/chrome/cros_ec_proto.c
>> +++ b/drivers/platform/chrome/cros_ec_proto.c
>> @@ -456,7 +456,10 @@ int cros_ec_query_all(struct cros_ec_device *ec_dev)
>> if (ret < 0 || ver_mask == 0)
>> ec_dev->mkbp_event_supported = 0;
>> else
>> - ec_dev->mkbp_event_supported = 1;
>> + ec_dev->mkbp_event_supported = fls(ver_mask);
>> +
>> + dev_dbg(ec_dev->dev, "MKBP support version %u\n",
>> + ec_dev->mkbp_event_supported - 1);
>>
>> /* Probe if host sleep v1 is supported for S0ix failure detection. */
>> ret = cros_ec_get_host_command_version_mask(ec_dev,
>> @@ -569,6 +572,7 @@ EXPORT_SYMBOL(cros_ec_cmd_xfer_status);
>>
>> static int get_next_event_xfer(struct cros_ec_device *ec_dev,
>> struct cros_ec_command *msg,
>> + struct ec_response_get_next_event_v1 *event,
>> int version, uint32_t size)
>> {
>> int ret;
>> @@ -581,7 +585,7 @@ static int get_next_event_xfer(struct cros_ec_device *ec_dev,
>> ret = cros_ec_cmd_xfer(ec_dev, msg);
>> if (ret > 0) {
>> ec_dev->event_size = ret - 1;
>> - memcpy(&ec_dev->event_data, msg->data, ret);
>> + ec_dev->event_data = *event;
>> }
>>
>> return ret;
>> @@ -589,30 +593,26 @@ static int get_next_event_xfer(struct cros_ec_device *ec_dev,
>>
>> static int get_next_event(struct cros_ec_device *ec_dev)
>> {
>> - u8 buffer[sizeof(struct cros_ec_command) + sizeof(ec_dev->event_data)];
>> - struct cros_ec_command *msg = (struct cros_ec_command *)&buffer;
>> - static int cmd_version = 1;
>> - int ret;
>> + struct {
>> + struct cros_ec_command msg;
>> + struct ec_response_get_next_event_v1 event;
>> + } __packed buf;
>> + struct cros_ec_command *msg = &buf.msg;
>> + struct ec_response_get_next_event_v1 *event = &buf.event;
>> + const int cmd_version = ec_dev->mkbp_event_supported - 1;
>>
>> + memset(msg, 0, sizeof(*msg));
>> if (ec_dev->suspended) {
>> dev_dbg(ec_dev->dev, "Device suspended.\n");
>> return -EHOSTDOWN;
>> }
>>
>> - if (cmd_version == 1) {
>> - ret = get_next_event_xfer(ec_dev, msg, cmd_version,
>> - sizeof(struct ec_response_get_next_event_v1));
>> - if (ret < 0 || msg->result != EC_RES_INVALID_VERSION)
>> - return ret;
>> -
>> - /* Fallback to version 0 for future send attempts */
>> - cmd_version = 0;
>> - }
>> -
>> - ret = get_next_event_xfer(ec_dev, msg, cmd_version,
>> + if (cmd_version == 0)
>> + return get_next_event_xfer(ec_dev, msg, event, 0,
>> sizeof(struct ec_response_get_next_event));
>>
>> - return ret;
>> + return get_next_event_xfer(ec_dev, msg, event, cmd_version,
>> + sizeof(struct ec_response_get_next_event_v1));
>> }
>>
>> static int get_keyboard_state_event(struct cros_ec_device *ec_dev)
>> @@ -639,32 +639,55 @@ static int get_keyboard_state_event(struct cros_ec_device *ec_dev)
>> * @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.
>> + * @has_more_events: Pointer to bool set to true if more than one event is
>> + * pending.
>> + * Some EC will set this flag to indicate cros_ec_get_next_event()
>> + * can be called multiple times in a row.
>> + * It is an optimization to prevent issuing a EC command for
>> + * nothing or wait for another interrupt from the EC to process
>> + * the next message.
>> + * Ignored if null.
>> *
>> * Return: negative error code on errors; 0 for no data; or else number of
>> * bytes received (i.e., an event was retrieved successfully). Event types are
>> * written out to @ec_dev->event_data.event_type on success.
>> */
>> -int cros_ec_get_next_event(struct cros_ec_device *ec_dev, bool *wake_event)
>> +int cros_ec_get_next_event(struct cros_ec_device *ec_dev,
>> + bool *wake_event,
>> + bool *has_more_events)
>> {
>> u8 event_type;
>> u32 host_event;
>> int ret;
>>
>> - if (!ec_dev->mkbp_event_supported) {
>> - ret = get_keyboard_state_event(ec_dev);
>> - if (ret <= 0)
>> - return ret;
>> + /*
>> + * Default value for wake_event.
>> + * Wake up on keyboard event, wake up for spurious interrupt or link
>> + * error to the EC.
>> + */
>> + if (wake_event)
>> + *wake_event = true;
>>
>> - if (wake_event)
>> - *wake_event = true;
>> + /*
>> + * Default value for has_more_events.
>> + * EC will raise another interrupt if AP does not process all events
>> + * anyway.
>> + */
>> + if (has_more_events)
>> + *has_more_events = false;
>>
>> - return ret;
>> - }
>> + if (!ec_dev->mkbp_event_supported)
>> + return get_keyboard_state_event(ec_dev);
>>
>> ret = get_next_event(ec_dev);
>> if (ret <= 0)
>> return ret;
>>
>> + if (has_more_events)
>> + *has_more_events = ec_dev->event_data.event_type &
>> + EC_MKBP_HAS_MORE_EVENTS;
>> + ec_dev->event_data.event_type &= EC_MKBP_EVENT_TYPE_MASK;
>> +
>> if (wake_event) {
>> event_type = ec_dev->event_data.event_type;
>> host_event = cros_ec_get_host_event(ec_dev);
>> @@ -679,11 +702,7 @@ int cros_ec_get_next_event(struct cros_ec_device *ec_dev, bool *wake_event)
>> else if (host_event &&
>> !(host_event & ec_dev->host_event_wake_mask))
>> *wake_event = false;
>> - /* Consider all other events as wake events. */
>> - else
>> - *wake_event = true;
>> }
>> -
>
> Nitpick. Unrelated whitespace change ;)
>
>> return ret;
>> }
>> EXPORT_SYMBOL(cros_ec_get_next_event);
>> diff --git a/drivers/platform/chrome/cros_ec_rpmsg.c b/drivers/platform/chrome/cros_ec_rpmsg.c
>> index 0c3738c3244d..bd068afe43b5 100644
>> --- a/drivers/platform/chrome/cros_ec_rpmsg.c
>> +++ b/drivers/platform/chrome/cros_ec_rpmsg.c
>> @@ -143,22 +143,11 @@ cros_ec_rpmsg_host_event_function(struct work_struct *host_event_work)
>> struct cros_ec_rpmsg,
>> host_event_work);
>> struct cros_ec_device *ec_dev = dev_get_drvdata(&ec_rpmsg->rpdev->dev);
>> - bool wake_event = true;
>> - int ret;
>> -
>> - 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);
>> + bool ec_has_more_events;
>>
>> - if (ret > 0)
>> - blocking_notifier_call_chain(&ec_dev->event_notifier,
>> - 0, ec_dev);
>> + do {
>> + ec_has_more_events = cros_ec_handle_event(ec_dev);
>> + } while (ec_has_more_events);
>> }
>>
>> static int cros_ec_rpmsg_callback(struct rpmsg_device *rpdev, void *data,
>> diff --git a/include/linux/platform_data/cros_ec_proto.h b/include/linux/platform_data/cros_ec_proto.h
>> index b183024fef1f..e238930ae967 100644
>> --- a/include/linux/platform_data/cros_ec_proto.h
>> +++ b/include/linux/platform_data/cros_ec_proto.h
>> @@ -116,7 +116,9 @@ struct cros_ec_command {
>> * code.
>> * @pkt_xfer: Send packet to EC and get response.
>> * @lock: One transaction at a time.
>> - * @mkbp_event_supported: True if this EC supports the MKBP event protocol.
>> + * @mkbp_event_supported: 0 if MKBP not supported. Otherwise its value is
>> + * the maximum supported version of the MKBP host event
>> + * command + 1.
>> * @host_sleep_v1: True if this EC supports the sleep v1 command.
>> * @event_notifier: Interrupt event notifier for transport devices.
>> * @event_data: Raw payload transferred with the MKBP event.
>> @@ -156,7 +158,7 @@ struct cros_ec_device {
>> int (*pkt_xfer)(struct cros_ec_device *ec,
>> struct cros_ec_command *msg);
>> struct mutex lock;
>> - bool mkbp_event_supported;
>> + u8 mkbp_event_supported;
>> bool host_sleep_v1;
>> struct blocking_notifier_head event_notifier;
>>
>> @@ -205,7 +207,9 @@ int cros_ec_unregister(struct cros_ec_device *ec_dev);
>>
>> int cros_ec_query_all(struct cros_ec_device *ec_dev);
>>
>> -int cros_ec_get_next_event(struct cros_ec_device *ec_dev, bool *wake_event);
>> +int cros_ec_get_next_event(struct cros_ec_device *ec_dev,
>> + bool *wake_event,
>> + bool *has_more_events);
>>
>> u32 cros_ec_get_host_event(struct cros_ec_device *ec_dev);
>>
>> @@ -213,6 +217,8 @@ int cros_ec_check_features(struct cros_ec_dev *ec, int feature);
>>
>> int cros_ec_get_sensor_count(struct cros_ec_dev *ec);
>>
>> +bool cros_ec_handle_event(struct cros_ec_device *ec_dev);
>> +
>> /**
>> * cros_ec_get_time_ns - Return time in ns.
>> *
>