From: Yicheng Li yichengli@chromium.org
[ Upstream commit 42cd0ab476e2daffc23982c37822a78f9a53cdd5 ]
RO and RW of EC may have different EC protocol version. If EC transitions between RO and RW, but AP does not reboot (this is true for fingerprint microcontroller / cros_fp, but not true for main ec / cros_ec), the AP still uses the protocol version queried before transition, which can cause problems. In the case of fingerprint microcontroller, this causes AP to send the wrong version of EC_CMD_GET_NEXT_EVENT to RO in the interrupt handler, which in turn prevents RO to clear the interrupt line to AP, in an infinite loop.
Once an EC_HOST_EVENT_INTERFACE_READY is received, we know that there might have been a transition between RO and RW, so re-query the protocol.
Signed-off-by: Yicheng Li yichengli@chromium.org Tested-by: Marek Szyprowski m.szyprowski@samsung.com Reviewed-by: Gwendal Grignou gwendal@chromium.org Signed-off-by: Enric Balletbo i Serra enric.balletbo@collabora.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/platform/chrome/cros_ec.c | 30 +++++++++++++++++++++ include/linux/platform_data/cros_ec_proto.h | 4 +++ 2 files changed, 34 insertions(+)
diff --git a/drivers/platform/chrome/cros_ec.c b/drivers/platform/chrome/cros_ec.c index 6d6ce86a1408a..e5e1bbb270914 100644 --- a/drivers/platform/chrome/cros_ec.c +++ b/drivers/platform/chrome/cros_ec.c @@ -137,6 +137,24 @@ static int cros_ec_sleep_event(struct cros_ec_device *ec_dev, u8 sleep_event) return ret; }
+static int cros_ec_ready_event(struct notifier_block *nb, + unsigned long queued_during_suspend, + void *_notify) +{ + struct cros_ec_device *ec_dev = container_of(nb, struct cros_ec_device, + notifier_ready); + u32 host_event = cros_ec_get_host_event(ec_dev); + + if (host_event & EC_HOST_EVENT_MASK(EC_HOST_EVENT_INTERFACE_READY)) { + mutex_lock(&ec_dev->lock); + cros_ec_query_all(ec_dev); + mutex_unlock(&ec_dev->lock); + return NOTIFY_OK; + } + + return NOTIFY_DONE; +} + /** * cros_ec_register() - Register a new ChromeOS EC, using the provided info. * @ec_dev: Device to register. @@ -236,6 +254,18 @@ int cros_ec_register(struct cros_ec_device *ec_dev) dev_dbg(ec_dev->dev, "Error %d clearing sleep event to ec", err);
+ if (ec_dev->mkbp_event_supported) { + /* + * Register the notifier for EC_HOST_EVENT_INTERFACE_READY + * event. + */ + ec_dev->notifier_ready.notifier_call = cros_ec_ready_event; + err = blocking_notifier_chain_register(&ec_dev->event_notifier, + &ec_dev->notifier_ready); + if (err) + return err; + } + dev_info(dev, "Chrome EC device registered\n");
return 0; diff --git a/include/linux/platform_data/cros_ec_proto.h b/include/linux/platform_data/cros_ec_proto.h index 30098a5515231..e6af1b4a7cbcf 100644 --- a/include/linux/platform_data/cros_ec_proto.h +++ b/include/linux/platform_data/cros_ec_proto.h @@ -126,6 +126,9 @@ struct cros_ec_command { * @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 * a new event. + * @notifier_ready: The notifier_block to let the kernel re-query EC + * communication protocol when the EC sends + * EC_HOST_EVENT_INTERFACE_READY. * @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 @@ -167,6 +170,7 @@ struct cros_ec_device { u32 host_event_wake_mask; u32 last_resume_result; ktime_t last_event_time; + struct notifier_block notifier_ready;
/* The platform devices used by the mfd driver */ struct platform_device *ec;