From 420d1689442585f5a25ac1250c0e11a07ecd5cf9 Mon Sep 17 00:00:00 2001 From: Alexander Usyskin Date: Wed, 19 Oct 2016 01:34:48 +0300 Subject: mei: txe: don't clean an unprocessed interrupt cause. commit 43605e293eb13c07acb546c14f407a271837af17 upstream. SEC registers are not accessible when the TXE device is in low power state, hence the SEC interrupt cannot be processed if device is not awake. In some rare cases entrance to low power state (aliveness off) and input ready bits can be signaled at the same time, resulting in communication stall as input ready won't be signaled again after waking up. To resolve this IPC_HHIER_SEC bit in HHISR_REG should not be cleaned if the interrupt is not processed. Signed-off-by: Alexander Usyskin Signed-off-by: Tomas Winkler Signed-off-by: Greg Kroah-Hartman --- drivers/misc/mei/hw-txe.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/misc/mei/hw-txe.c b/drivers/misc/mei/hw-txe.c index 4a6c1b85f11e..2d23cdf8a734 100644 --- a/drivers/misc/mei/hw-txe.c +++ b/drivers/misc/mei/hw-txe.c @@ -978,11 +978,13 @@ static bool mei_txe_check_and_ack_intrs(struct mei_device *dev, bool do_ack) hisr = mei_txe_br_reg_read(hw, HISR_REG); aliveness = mei_txe_aliveness_get(dev); - if (hhisr & IPC_HHIER_SEC && aliveness) + if (hhisr & IPC_HHIER_SEC && aliveness) { ipc_isr = mei_txe_sec_reg_read_silent(hw, SEC_IPC_HOST_INT_STATUS_REG); - else + } else { ipc_isr = 0; + hhisr &= ~IPC_HHIER_SEC; + } generated = generated || (hisr & HISR_INT_STS_MSK) || -- cgit v1.2.3