| Message ID | 1677066231-14931-1-git-send-email-quic_vpernami@quicinc.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [v4] bus: mhi: host: Avoid ringing EV DB if there is no elements to process | expand |
On 2/22/2023 4:43 AM, Vivek Pernamitta wrote: > Avoid ringing Event DB if there is no elements to process. This is almost exactly identical to $SUBJECT and therefore redundant. > 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. I think that you could be more clear on why this is a problem that should be addressed. Perhaps add a sentence like "These doorbell events needlessly interrupt the MHI device to checked for ring elements when there are none." With the commit text updated, you can add Reviewed-by: Jeffrey Hugo <quic_jhugo@quicinc.com> > > Signed-off-by: Vivek Pernamitta <quic_vpernami@quicinc.com> > > --- > changes since v3: > - Updating commit text for multiple versions of patches. > changes since v2: > - Updated comments in code. > changes since v1: > - Add an check to avoid ringing EV DB in mhi_process_ctrl_ev_ring(). > --- > drivers/bus/mhi/host/main.c | 8 ++++++-- > 1 file changed, 6 insertions(+), 2 deletions(-) > > diff --git a/drivers/bus/mhi/host/main.c b/drivers/bus/mhi/host/main.c > index df0fbfe..1bbdb75 100644 > --- a/drivers/bus/mhi/host/main.c > +++ b/drivers/bus/mhi/host/main.c > @@ -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); >
diff --git a/drivers/bus/mhi/host/main.c b/drivers/bus/mhi/host/main.c index df0fbfe..1bbdb75 100644 --- a/drivers/bus/mhi/host/main.c +++ b/drivers/bus/mhi/host/main.c @@ -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);
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@quicinc.com> --- changes since v3: - Updating commit text for multiple versions of patches. changes since v2: - Updated comments in code. changes since v1: - Add an check to avoid ringing EV DB in mhi_process_ctrl_ev_ring(). --- drivers/bus/mhi/host/main.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)