mei: txe: don't clean an unprocessed interrupt cause.

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.

Cc: stable@vger.kernel.org
Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Alexander Usyskin 2016-10-19 01:34:48 +03:00 committed by Greg Kroah-Hartman
parent 4afb604e2d
commit 43605e293e

View File

@ -981,11 +981,13 @@ 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) ||