Re: [PATCH 2/5] firmware: arm_scmi: fix transfer missing re-initialization
From: Etienne Carriere
Date: Fri Oct 09 2020 - 08:38:32 EST
On Thu, 8 Oct 2020 at 23:18, Sudeep Holla <sudeep.holla@xxxxxxx> wrote:
>
> On Thu, Oct 08, 2020 at 04:37:19PM +0200, Etienne Carriere wrote:
> > Implement helper function scmi_do_xfer_again() to process consecutive
> > transfers that are initialized only once with scmi_xfer_get_init()
> > and hence get the pool completion and responses message length not
> > reloaded regarding last completed transfer.
> >
> > Signed-off-by: Etienne Carriere <etienne.carriere@xxxxxxxxxx>
> > ---
> > drivers/firmware/arm_scmi/base.c | 2 +-
> > drivers/firmware/arm_scmi/clock.c | 2 +-
> > drivers/firmware/arm_scmi/common.h | 2 ++
> > drivers/firmware/arm_scmi/driver.c | 10 ++++++++++
> > drivers/firmware/arm_scmi/perf.c | 2 +-
> > drivers/firmware/arm_scmi/sensors.c | 2 +-
> > 6 files changed, 16 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/firmware/arm_scmi/base.c b/drivers/firmware/arm_scmi/base.c
> > index 9853bd3c4d45..508f214baa1b 100644
> > --- a/drivers/firmware/arm_scmi/base.c
> > +++ b/drivers/firmware/arm_scmi/base.c
> > @@ -183,7 +183,7 @@ static int scmi_base_implementation_list_get(const struct scmi_handle *handle,
> > /* Set the number of protocols to be skipped/already read */
> > *num_skip = cpu_to_le32(tot_num_ret);
> >
> > - ret = scmi_do_xfer(handle, t);
> > + ret = scmi_do_xfer_again(handle, t);
> > if (ret)
> > break;
> >
> > diff --git a/drivers/firmware/arm_scmi/clock.c b/drivers/firmware/arm_scmi/clock.c
> > index c1cfe3ee3d55..9bb54c1a8d55 100644
> > --- a/drivers/firmware/arm_scmi/clock.c
> > +++ b/drivers/firmware/arm_scmi/clock.c
> > @@ -161,7 +161,7 @@ scmi_clock_describe_rates_get(const struct scmi_handle *handle, u32 clk_id,
> > /* Set the number of rates to be skipped/already read */
> > clk_desc->rate_index = cpu_to_le32(tot_rate_cnt);
> >
> > - ret = scmi_do_xfer(handle, t);
> > + ret = scmi_do_xfer_again(handle, t);
> > if (ret)
> > goto err;
> >
> > diff --git a/drivers/firmware/arm_scmi/common.h b/drivers/firmware/arm_scmi/common.h
> > index 37fb583f1bf5..6d4eea7b0f3e 100644
> > --- a/drivers/firmware/arm_scmi/common.h
> > +++ b/drivers/firmware/arm_scmi/common.h
> > @@ -143,6 +143,8 @@ struct scmi_xfer {
> >
> > void scmi_xfer_put(const struct scmi_handle *h, struct scmi_xfer *xfer);
> > int scmi_do_xfer(const struct scmi_handle *h, struct scmi_xfer *xfer);
> > +int scmi_do_xfer_again(const struct scmi_handle *handle,
> > + struct scmi_xfer *xfer);
> > int scmi_do_xfer_with_response(const struct scmi_handle *h,
> > struct scmi_xfer *xfer);
> > int scmi_xfer_get_init(const struct scmi_handle *h, u8 msg_id, u8 prot_id,
> > diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
> > index c5dea87edf8f..887cb8249db0 100644
> > --- a/drivers/firmware/arm_scmi/driver.c
> > +++ b/drivers/firmware/arm_scmi/driver.c
> > @@ -402,6 +402,16 @@ int scmi_do_xfer(const struct scmi_handle *handle, struct scmi_xfer *xfer)
> > return ret;
> > }
> >
> > +int scmi_do_xfer_again(const struct scmi_handle *handle, struct scmi_xfer *xfer)
> > +{
> > + struct scmi_info *info = handle_to_scmi_info(handle);
> > +
> > + xfer->rx.len = info->desc->max_msg_size;
>
> I am tempted to just have helper for above and use it where needed.
> Or may be I just don't like the name of the function, how about
> scmi_do_xfer_rxlen_reinit or anything else. Suggestions ?
I think a smoother way would be that scmi_do_xfer() initializes
both
xfer->rx.len = info->desc->max_msg_size
and
xfer->hdr.poll_completion = false
instead of doing that from scmi_xfer_get_init().
>
> > + xfer->hdr.poll_completion = false;
>
> Do we really need the above ?
I think so. Once a transfer is completed, poll_completion is true. But
the next transfer we expect should start assuming completion is not
yet done, hence this reset to false.
Regards,
Etienne
>
> --
> Regards,
> Sudeep