[PATCH V1] bus: mhi: host: Avoid ringing EV DB if there is no elements to process

[Vivek Pernamitta]

Avoid ringing Event DB if there is no elements to process.
As mhi_poll function can be called by mhi client drivers
which will call process_event, which will ring DB even if
there no ring elements to process.

Signed-off-by: Vivek Pernamitta <quic_vpernami@xxxxxxxxxxx>
---
 drivers/bus/mhi/host/main.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/bus/mhi/host/main.c b/drivers/bus/mhi/host/main.c
index df0fbfe..8bf8394 100644
--- a/drivers/bus/mhi/host/main.c
+++ b/drivers/bus/mhi/host/main.c
@@ -1031,7 +1031,9 @@ int mhi_process_data_event_ring(struct mhi_controller *mhi_cntrl,
 		count++;
 	}
 	read_lock_bh(&mhi_cntrl->pm_lock);
-	if (likely(MHI_DB_ACCESS_VALID(mhi_cntrl)))
+
+	/* Ring EV DB only if there is any pending element to process */
+	if (likely(MHI_DB_ACCESS_VALID(mhi_cntrl)) && count)
 		mhi_ring_er_db(mhi_event);
 	read_unlock_bh(&mhi_cntrl->pm_lock);
 
-- 
2.7.4