Hello Lina, On Thu, Feb 15, 2018 at 9:35 AM, Lina Iyer <il...@codeaurora.org> wrote: > Platform drivers need make a lot of resource state requests at the same > time, say, at the start or end of an usecase. It can be quite > inefficient to send each request separately. Instead they can give the > RPMH library a batch of requests to be sent and wait on the whole > transaction to be complete. > > rpmh_write_batch() is a blocking call that can be used to send multiple > RPMH command sets. Each RPMH command set is set asynchronously and the > API blocks until all the command sets are complete and receive their > tx_done callbacks. > > Signed-off-by: Lina Iyer <il...@codeaurora.org> > --- > drivers/soc/qcom/rpmh.c | 150 > ++++++++++++++++++++++++++++++++++++++++++++++++ > include/soc/qcom/rpmh.h | 8 +++ > 2 files changed, 158 insertions(+) > > diff --git a/drivers/soc/qcom/rpmh.c b/drivers/soc/qcom/rpmh.c > index dff4c46be3af..6f60bb9a4dfa 100644 > --- a/drivers/soc/qcom/rpmh.c > +++ b/drivers/soc/qcom/rpmh.c [...] > @@ -394,6 +537,11 @@ int rpmh_flush(struct rpmh_client *rc) > } > spin_unlock_irqrestore(&rpm->lock, flags); > > + /* First flush the cached batch requests */ > + ret = flush_batch(rc); > + if (ret) > + return ret; > + > /* > * Nobody else should be calling this function other than system PM,, > * hence we can run without locks. > @@ -438,6 +586,8 @@ int rpmh_invalidate(struct rpmh_client *rc) > if (IS_ERR_OR_NULL(rc)) > return -EINVAL; > > + invalidate_batch(rc); > +
Similarly to my comments in patch 7, aren't there races here with adding new elements? After flush_batch, but before invalidate_batch, somebody could call cache_batch, which would add new things on the end of the array. These new items would be clobbered by invalidate_batch, without having been flushed first. -Evan
