bus: mhi: host: Avoid ringing EV DB if there are no elements to process

Currently, mhi_process_data_event_ring()/mhi_process_ctrl_ev_ring() APIs
are ringing DB even if there are no ring elements to process. This could
cause the device to process the DB event in the absence of ring elements.
So to avoid this unnecessary device processing, let's ring event DB only
if there are any ring elements to process.

Signed-off-by: Vivek Pernamitta <quic_vpernami@quicinc.com>
Reviewed-by: Jeffrey Hugo <quic_jhugo@quicinc.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/1680601458-9105-1-git-send-email-quic_vpernami@quicinc.com
[mani: massaged the commit message a bit]
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
This commit is contained in:
Vivek Pernamitta 2023-04-04 15:14:16 +05:30 committed by Manivannan Sadhasivam
parent c2dbd34f6a
commit 4308c6878a

View file

@ -961,7 +961,9 @@ int mhi_process_ctrl_ev_ring(struct mhi_controller *mhi_cntrl,
}
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);
@ -1031,7 +1033,9 @@ 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);