From 3dc196eae1db548f05e53e5875ff87b8ff79f249 Mon Sep 17 00:00:00 2001 From: Alexander Usyskin Date: Sat, 13 Jun 2015 08:51:17 +0300 Subject: mei: me: wait for power gating exit confirmation Fix the hbm power gating state machine so it will wait till it receives confirmation interrupt for the PG_ISOLATION_EXIT message. In process of the suspend flow the devices first have to exit from the power gating state (runtime pm resume). If we do not handle the confirmation interrupt after sending PG_ISOLATION_EXIT message, we may receive it already after the suspend flow has changed the device state and interrupt will be interpreted as a spurious event, consequently link reset will be invoked which will prevent the device from completing the suspend flow kernel: [6603] mei_reset:136: mei_me 0000:00:16.0: powering down: end of reset kernel: [476] mei_me_irq_thread_handler:643: mei_me 0000:00:16.0: function called after ISR to handle the interrupt processing. kernel: mei_me 0000:00:16.0: FW not ready: resetting Cc: #3.18+ Cc: Gabriele Mazzotta Link: https://bugzilla.kernel.org/show_bug.cgi?id=86241 Link: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=770397 Tested-by: Gabriele Mazzotta Signed-off-by: Alexander Usyskin Signed-off-by: Tomas Winkler Signed-off-by: Greg Kroah-Hartman --- drivers/misc/mei/hw-me.c | 59 ++++++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 55 insertions(+), 4 deletions(-) (limited to 'drivers/misc/mei/hw-me.c') diff --git a/drivers/misc/mei/hw-me.c b/drivers/misc/mei/hw-me.c index 6fb75e62a764..43d7101ff993 100644 --- a/drivers/misc/mei/hw-me.c +++ b/drivers/misc/mei/hw-me.c @@ -663,17 +663,46 @@ int mei_me_pg_exit_sync(struct mei_device *dev) mutex_lock(&dev->device_lock); reply: - if (dev->pg_event == MEI_PG_EVENT_RECEIVED) - ret = mei_hbm_pg(dev, MEI_PG_ISOLATION_EXIT_RES_CMD); + if (dev->pg_event != MEI_PG_EVENT_RECEIVED) { + ret = -ETIME; + goto out; + } + + dev->pg_event = MEI_PG_EVENT_INTR_WAIT; + ret = mei_hbm_pg(dev, MEI_PG_ISOLATION_EXIT_RES_CMD); + if (ret) + return ret; + + mutex_unlock(&dev->device_lock); + wait_event_timeout(dev->wait_pg, + dev->pg_event == MEI_PG_EVENT_INTR_RECEIVED, timeout); + mutex_lock(&dev->device_lock); + + if (dev->pg_event == MEI_PG_EVENT_INTR_RECEIVED) + ret = 0; else ret = -ETIME; +out: dev->pg_event = MEI_PG_EVENT_IDLE; hw->pg_state = MEI_PG_OFF; return ret; } +/** + * mei_me_pg_in_transition - is device now in pg transition + * + * @dev: the device structure + * + * Return: true if in pg transition, false otherwise + */ +static bool mei_me_pg_in_transition(struct mei_device *dev) +{ + return dev->pg_event >= MEI_PG_EVENT_WAIT && + dev->pg_event <= MEI_PG_EVENT_INTR_WAIT; +} + /** * mei_me_pg_is_enabled - detect if PG is supported by HW * @@ -704,6 +733,24 @@ notsupported: return false; } +/** + * mei_me_pg_intr - perform pg processing in interrupt thread handler + * + * @dev: the device structure + */ +static void mei_me_pg_intr(struct mei_device *dev) +{ + struct mei_me_hw *hw = to_me_hw(dev); + + if (dev->pg_event != MEI_PG_EVENT_INTR_WAIT) + return; + + dev->pg_event = MEI_PG_EVENT_INTR_RECEIVED; + hw->pg_state = MEI_PG_OFF; + if (waitqueue_active(&dev->wait_pg)) + wake_up(&dev->wait_pg); +} + /** * mei_me_irq_quick_handler - The ISR of the MEI device * @@ -761,6 +808,8 @@ irqreturn_t mei_me_irq_thread_handler(int irq, void *dev_id) goto end; } + mei_me_pg_intr(dev); + /* check if we need to start the dev */ if (!mei_host_is_ready(dev)) { if (mei_hw_is_ready(dev)) { @@ -797,9 +846,10 @@ irqreturn_t mei_me_irq_thread_handler(int irq, void *dev_id) /* * During PG handshake only allowed write is the replay to the * PG exit message, so block calling write function - * if the pg state is not idle + * if the pg event is in PG handshake */ - if (dev->pg_event == MEI_PG_EVENT_IDLE) { + if (dev->pg_event != MEI_PG_EVENT_WAIT && + dev->pg_event != MEI_PG_EVENT_RECEIVED) { rets = mei_irq_write_handler(dev, &complete_list); dev->hbuf_is_ready = mei_hbuf_is_ready(dev); } @@ -824,6 +874,7 @@ static const struct mei_hw_ops mei_me_hw_ops = { .hw_config = mei_me_hw_config, .hw_start = mei_me_hw_start, + .pg_in_transition = mei_me_pg_in_transition, .pg_is_enabled = mei_me_pg_is_enabled, .intr_clear = mei_me_intr_clear, -- cgit v1.2.3