Hi Gwendal, Cc'ing some ISHTP people as I don't have the hardware. If possible, could any of you give us your Tested-by tag?
On 21/10/19 7:53, Gwendal Grignou wrote: > To improve sensor timestamp precision, given EC and AP are in > different time domains, the AP needs to try to record the exact > moment an event was signalled to the AP by the EC as soon as > possible after it happens. > > First thing in the hard irq is the best place for this. > > Signed-off-by: Gwendal Grignou <[email protected]> Gwendal, I am right saying that this patch can be applied independently of the others and has no dependencies? Thanks, Enric > --- > Changes in v2: > Make cros_ec_get_time_ns inline. > Using ktime_t instead of s64 when dealing with time. > Added code in ishtp to gather timestamp. > > drivers/platform/chrome/cros_ec.c | 12 +++++++++++- > drivers/platform/chrome/cros_ec_ishtp.c | 17 +++++++++++++++-- > drivers/platform/chrome/cros_ec_lpc.c | 2 ++ > include/linux/platform_data/cros_ec_proto.h | 16 ++++++++++++++++ > 4 files changed, 44 insertions(+), 3 deletions(-) > > diff --git a/drivers/platform/chrome/cros_ec.c > b/drivers/platform/chrome/cros_ec.c > index 9b2d07422e175..739f3cffe26e3 100644 > --- a/drivers/platform/chrome/cros_ec.c > +++ b/drivers/platform/chrome/cros_ec.c > @@ -31,6 +31,15 @@ static struct cros_ec_platform pd_p = { > .cmd_offset = EC_CMD_PASSTHRU_OFFSET(CROS_EC_DEV_PD_INDEX), > }; > > +static irqreturn_t ec_irq_handler(int irq, void *data) > +{ > + struct cros_ec_device *ec_dev = data; > + > + ec_dev->last_event_time = cros_ec_get_time_ns(); > + > + return IRQ_WAKE_THREAD; > +} > + > static irqreturn_t ec_irq_thread(int irq, void *data) > { > struct cros_ec_device *ec_dev = data; > @@ -141,7 +150,8 @@ int cros_ec_register(struct cros_ec_device *ec_dev) > } > > if (ec_dev->irq) { > - err = devm_request_threaded_irq(dev, ec_dev->irq, NULL, > + err = devm_request_threaded_irq( > + dev, ec_dev->irq, ec_irq_handler, > ec_irq_thread, IRQF_TRIGGER_LOW | IRQF_ONESHOT, > "chromeos-ec", ec_dev); > if (err) { > diff --git a/drivers/platform/chrome/cros_ec_ishtp.c > b/drivers/platform/chrome/cros_ec_ishtp.c > index 25ca2c894b4de..5c848f22b44b4 100644 > --- a/drivers/platform/chrome/cros_ec_ishtp.c > +++ b/drivers/platform/chrome/cros_ec_ishtp.c > @@ -200,13 +200,14 @@ static int ish_send(struct ishtp_cl_data *client_data, > * process_recv() - Received and parse incoming packet > * @cros_ish_cl: Client instance to get stats > * @rb_in_proc: Host interface message buffer > + * @timestamp: Timestamp of when parent callback started > * > * Parse the incoming packet. If it is a response packet then it will > * update per instance flags and wake up the caller waiting to for the > * response. If it is an event packet then it will schedule event work. > */ > static void process_recv(struct ishtp_cl *cros_ish_cl, > - struct ishtp_cl_rb *rb_in_proc) > + struct ishtp_cl_rb *rb_in_proc, ktime_t timestamp) > { > size_t data_len = rb_in_proc->buf_idx; > struct ishtp_cl_data *client_data = > @@ -295,6 +296,11 @@ static void process_recv(struct ishtp_cl *cros_ish_cl, > break; > > case CROS_MKBP_EVENT: > + /* > + * Set timestamp from beginning of function since we actually > + * got an incoming MKBP event > + */ > + client_data->ec_dev->last_event_time = timestamp; > /* The event system doesn't send any data in buffer */ > schedule_work(&client_data->work_ec_evt); > > @@ -322,10 +328,17 @@ static void ish_event_cb(struct ishtp_cl_device > *cl_device) > { > struct ishtp_cl_rb *rb_in_proc; > struct ishtp_cl *cros_ish_cl = ishtp_get_drvdata(cl_device); > + ktime_t timestamp; > + > + /* > + * Take timestamp as close to hardware interrupt as possible for sensor > + * timestamps. > + */ > + timestamp = cros_ec_get_time_ns(); > > while ((rb_in_proc = ishtp_cl_rx_get_rb(cros_ish_cl)) != NULL) { > /* Decide what to do with received data */ > - process_recv(cros_ish_cl, rb_in_proc); > + process_recv(cros_ish_cl, rb_in_proc, timestamp); > } > } > > diff --git a/drivers/platform/chrome/cros_ec_lpc.c > b/drivers/platform/chrome/cros_ec_lpc.c > index 7d10d909435ff..3c77496e164da 100644 > --- a/drivers/platform/chrome/cros_ec_lpc.c > +++ b/drivers/platform/chrome/cros_ec_lpc.c > @@ -313,6 +313,8 @@ static void cros_ec_lpc_acpi_notify(acpi_handle device, > u32 value, void *data) > { > struct cros_ec_device *ec_dev = data; > > + 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, > diff --git a/include/linux/platform_data/cros_ec_proto.h > b/include/linux/platform_data/cros_ec_proto.h > index 691f9e953a96a..b183024fef1f6 100644 > --- a/include/linux/platform_data/cros_ec_proto.h > +++ b/include/linux/platform_data/cros_ec_proto.h > @@ -122,6 +122,8 @@ struct cros_ec_command { > * @event_data: Raw payload transferred with the MKBP event. > * @event_size: Size in bytes of the event data. > * @host_event_wake_mask: Mask of host events that cause wake from suspend. > + * @last_event_time: exact time from the hard irq when we got notified of nit: s/e/E/ > + * a new event. > * @ec: The platform_device used by the mfd driver to interface with the > * main EC. > * @pd: The platform_device used by the mfd driver to interface with the > @@ -162,6 +164,7 @@ struct cros_ec_device { > int event_size; > u32 host_event_wake_mask; > u32 last_resume_result; > + ktime_t last_event_time; > > /* The platform devices used by the mfd driver */ > struct platform_device *ec; > @@ -210,4 +213,17 @@ int cros_ec_check_features(struct cros_ec_dev *ec, int > feature); > > int cros_ec_get_sensor_count(struct cros_ec_dev *ec); > > +/** > + * cros_ec_get_time_ns - Return time in ns. > + * > + * This is the function used to record the time for last_event_time in struct > + * cros_ec_device during the hard irq. > + * > + * Return: ktime_t format since boot. > + */ > +static inline ktime_t cros_ec_get_time_ns(void) > +{ > + return ktime_get_boottime_ns(); > +} > + > #endif /* __LINUX_CROS_EC_PROTO_H */ >
