[PATCH v3 05/12] bus: mhi: core: Prevent sending multiple RDDM entry callbacks

[Bhaumik Bhatt]

If an mhi_power_down() is initiated after the device has entered
RDDM and a status callback was provided for it, it is possible
that another BHI interrupt fires while waiting for the MHI
RESET to be cleared. If that happens, MHI host would have moved
a "disabled" execution environment and the check to allow sending
an RDDM status callback will pass when it is should not. Add a
check to see if MHI is in an active state before proceeding.

Signed-off-by: Bhaumik Bhatt <bbhatt@xxxxxxxxxxxxxx>
---
 drivers/bus/mhi/core/main.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/bus/mhi/core/main.c b/drivers/bus/mhi/core/main.c
index 1f32d67..172b48b 100644
--- a/drivers/bus/mhi/core/main.c
+++ b/drivers/bus/mhi/core/main.c
@@ -399,6 +399,10 @@ irqreturn_t mhi_intvec_threaded_handler(int irq_number, void *priv)
 
 	 /* If device supports RDDM don't bother processing SYS error */
 	if (mhi_cntrl->rddm_image) {
+		/* host may be performing a device power down already */
+		if (!mhi_is_active(mhi_cntrl))
+			goto exit_intvec;
+
 		if (mhi_cntrl->ee == MHI_EE_RDDM && mhi_cntrl->ee != ee) {
 			mhi_cntrl->status_cb(mhi_cntrl, MHI_CB_EE_RDDM);
 			wake_up_all(&mhi_cntrl->state_event);
-- 
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