| Message ID | 1586703004-13674-3-git-send-email-mkshah@codeaurora.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Invoke rpmh_flush for non OSI targets | expand |
Quoting Maulik Shah (2020-04-12 07:50:00) > Currently rpmh ctrlr dirty flag is set for all cases regardless of data > is really changed or not. Add changes to update dirty flag when data is > changed to newer values. Update dirty flag everytime when data in batch > cache is updated since rpmh_flush() may get invoked from any CPU instead > of only last CPU going to low power mode. > > Also move dirty flag updates to happen from within cache_lock and remove > unnecessary INIT_LIST_HEAD() call and a default case from switch. > > Fixes: 600513dfeef3 ("drivers: qcom: rpmh: cache sleep/wake state requests") > Signed-off-by: Maulik Shah <mkshah@codeaurora.org> > Reviewed-by: Srinivas Rao L <lsrao@codeaurora.org> > Reviewed-by: Evan Green <evgreen@chromium.org> > Reviewed-by: Douglas Anderson <dianders@chromium.org> > --- Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Quoting Maulik Shah (2020-04-12 07:50:00) > diff --git a/drivers/soc/qcom/rpmh.c b/drivers/soc/qcom/rpmh.c > index eb0ded0..03630ae 100644 > --- a/drivers/soc/qcom/rpmh.c > +++ b/drivers/soc/qcom/rpmh.c > @@ -133,26 +134,27 @@ static struct cache_req *cache_rpm_request(struct rpmh_ctrlr *ctrlr, > > req->addr = cmd->addr; > req->sleep_val = req->wake_val = UINT_MAX; > - INIT_LIST_HEAD(&req->list); > list_add_tail(&req->list, &ctrlr->cache); > > existing: > + old_sleep_val = req->sleep_val; > + old_wake_val = req->wake_val; > + > switch (state) { > case RPMH_ACTIVE_ONLY_STATE: > - if (req->sleep_val != UINT_MAX) > - req->wake_val = cmd->data; > - break; > case RPMH_WAKE_ONLY_STATE: > req->wake_val = cmd->data; > break; > case RPMH_SLEEP_STATE: > req->sleep_val = cmd->data; > break; > - default: > - break; > } > > - ctrlr->dirty = true; > + ctrlr->dirty = (req->sleep_val != old_sleep_val || > + req->wake_val != old_wake_val) && > + req->sleep_val != UINT_MAX && > + req->wake_val != UINT_MAX; Can this change ctrl->dirty from true to false? I'm worried that we need to make this a saturating assignment instead of an assignment. ctrl->dirty = ctrl->dirty || (req->sleep_val != .. ); > + > unlock: > spin_unlock_irqrestore(&ctrlr->cache_lock, flags); >
On Thu, Apr 16, 2020 at 4:59 PM Stephen Boyd <swboyd@chromium.org> wrote: > > Quoting Maulik Shah (2020-04-12 07:50:00) > > diff --git a/drivers/soc/qcom/rpmh.c b/drivers/soc/qcom/rpmh.c > > index eb0ded0..03630ae 100644 > > --- a/drivers/soc/qcom/rpmh.c > > +++ b/drivers/soc/qcom/rpmh.c > > @@ -133,26 +134,27 @@ static struct cache_req *cache_rpm_request(struct rpmh_ctrlr *ctrlr, > > > > req->addr = cmd->addr; > > req->sleep_val = req->wake_val = UINT_MAX; > > - INIT_LIST_HEAD(&req->list); > > list_add_tail(&req->list, &ctrlr->cache); > > > > existing: > > + old_sleep_val = req->sleep_val; > > + old_wake_val = req->wake_val; > > + > > switch (state) { > > case RPMH_ACTIVE_ONLY_STATE: > > - if (req->sleep_val != UINT_MAX) > > - req->wake_val = cmd->data; > > - break; > > case RPMH_WAKE_ONLY_STATE: > > req->wake_val = cmd->data; > > break; > > case RPMH_SLEEP_STATE: > > req->sleep_val = cmd->data; > > break; > > - default: > > - break; > > } > > > > - ctrlr->dirty = true; > > + ctrlr->dirty = (req->sleep_val != old_sleep_val || > > + req->wake_val != old_wake_val) && > > + req->sleep_val != UINT_MAX && > > + req->wake_val != UINT_MAX; > > Can this change ctrl->dirty from true to false? I'm worried that we need > to make this a saturating assignment instead of an assignment. > > ctrl->dirty = ctrl->dirty || (req->sleep_val != .. ); This seems like a serious problem with the current code and feels like we need a fix sooner rather than later. I'm sorry I missed it in review (and in fact, I probably suggested the exact code that's here so it's even more my fault). :( I posted: https://lore.kernel.org/r/20200417141531.1.Ia4b74158497213eabad7c3d474c50bfccb3f342e@changeid -Doug
diff --git a/drivers/soc/qcom/rpmh.c b/drivers/soc/qcom/rpmh.c index eb0ded0..03630ae 100644 --- a/drivers/soc/qcom/rpmh.c +++ b/drivers/soc/qcom/rpmh.c @@ -119,6 +119,7 @@ static struct cache_req *cache_rpm_request(struct rpmh_ctrlr *ctrlr, { struct cache_req *req; unsigned long flags; + u32 old_sleep_val, old_wake_val; spin_lock_irqsave(&ctrlr->cache_lock, flags); req = __find_req(ctrlr, cmd->addr); @@ -133,26 +134,27 @@ static struct cache_req *cache_rpm_request(struct rpmh_ctrlr *ctrlr, req->addr = cmd->addr; req->sleep_val = req->wake_val = UINT_MAX; - INIT_LIST_HEAD(&req->list); list_add_tail(&req->list, &ctrlr->cache); existing: + old_sleep_val = req->sleep_val; + old_wake_val = req->wake_val; + switch (state) { case RPMH_ACTIVE_ONLY_STATE: - if (req->sleep_val != UINT_MAX) - req->wake_val = cmd->data; - break; case RPMH_WAKE_ONLY_STATE: req->wake_val = cmd->data; break; case RPMH_SLEEP_STATE: req->sleep_val = cmd->data; break; - default: - break; } - ctrlr->dirty = true; + ctrlr->dirty = (req->sleep_val != old_sleep_val || + req->wake_val != old_wake_val) && + req->sleep_val != UINT_MAX && + req->wake_val != UINT_MAX; + unlock: spin_unlock_irqrestore(&ctrlr->cache_lock, flags); @@ -287,6 +289,7 @@ static void cache_batch(struct rpmh_ctrlr *ctrlr, struct batch_cache_req *req) spin_lock_irqsave(&ctrlr->cache_lock, flags); list_add_tail(&req->list, &ctrlr->batch_cache); + ctrlr->dirty = true; spin_unlock_irqrestore(&ctrlr->cache_lock, flags); } @@ -323,6 +326,7 @@ static void invalidate_batch(struct rpmh_ctrlr *ctrlr) list_for_each_entry_safe(req, tmp, &ctrlr->batch_cache, list) kfree(req); INIT_LIST_HEAD(&ctrlr->batch_cache); + ctrlr->dirty = true; spin_unlock_irqrestore(&ctrlr->cache_lock, flags); } @@ -507,7 +511,6 @@ int rpmh_invalidate(const struct device *dev) int ret; invalidate_batch(ctrlr); - ctrlr->dirty = true; do { ret = rpmh_rsc_invalidate(ctrlr_to_drv(ctrlr));
Currently rpmh ctrlr dirty flag is set for all cases regardless of data is really changed or not. Add changes to update dirty flag when data is changed to newer values. Update dirty flag everytime when data in batch cache is updated since rpmh_flush() may get invoked from any CPU instead of only last CPU going to low power mode. Also move dirty flag updates to happen from within cache_lock and remove unnecessary INIT_LIST_HEAD() call and a default case from switch. Fixes: 600513dfeef3 ("drivers: qcom: rpmh: cache sleep/wake state requests") Signed-off-by: Maulik Shah <mkshah@codeaurora.org> Reviewed-by: Srinivas Rao L <lsrao@codeaurora.org> Reviewed-by: Evan Green <evgreen@chromium.org> Reviewed-by: Douglas Anderson <dianders@chromium.org> --- drivers/soc/qcom/rpmh.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-)