mei: me: generate an interrupt if the hw indicates reset.
In rare case the driver may lose connection with the device after device
reset due to a missed interrupt. The driver will unlock the flow by
generating an interrupt towards the firmware (HIG) when the device is in
the resetting state. The FW is able to ignore the interrupt during
orderly flow. The effected platforms are skylake and newer.
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>
diff --git a/drivers/misc/mei/hw-me.c b/drivers/misc/mei/hw-me.c
index 23294b8..71216af 100644
--- a/drivers/misc/mei/hw-me.c
+++ b/drivers/misc/mei/hw-me.c
@@ -394,6 +394,19 @@
}
/**
+ * mei_me_hw_is_resetting - check whether the me(hw) is in reset
+ *
+ * @dev: mei device
+ * Return: bool
+ */
+static bool mei_me_hw_is_resetting(struct mei_device *dev)
+{
+ u32 mecsr = mei_me_mecsr_read(dev);
+
+ return (mecsr & ME_RST_HRA) == ME_RST_HRA;
+}
+
+/**
* mei_me_hw_ready_wait - wait until the me(hw) has turned ready
* or timeout is reached
*
@@ -1219,6 +1232,9 @@
goto end;
}
+ if (mei_me_hw_is_resetting(dev))
+ mei_hcsr_set_hig(dev);
+
mei_me_pg_intr(dev, me_intr_src(hcsr));
/* check if we need to start the dev */