Re: [PATCH v2 05/10] drivers: qcom: rpmh-rsc: write sleep/wake requests to TCS

[Lina Iyer]

Hi Evan,

Thanks for your review.

On Fri, Feb 16 2018 at 23:51 +0000, Evan Green wrote:
> Hello Lina,
>
> On Thu, Feb 15, 2018 at 9:35 AM, Lina Iyer <ilina@xxxxxxxxxxxxxx> wrote:
> > Sleep and wake requests are sent when the application processor
> > subsystem of the SoC is entering deep sleep states like in suspend.
> > These requests help lower the system power requirements when the
> > resources are not in use.
> >
> > Sleep and wake requests are written to the TCS slots but are not
> > triggered at the time of writing. The TCS are triggered by the firmware
> > after the last of the CPUs has executed its WFI. Since these requests
> > may come in different batches of requests, it is job of this controller
> > driver to find arrange the requests into the available TCSes.
> >
> > Signed-off-by: Lina Iyer <ilina@xxxxxxxxxxxxxx>
> > ---
> >  drivers/soc/qcom/rpmh-internal.h |   7 +++
> >  drivers/soc/qcom/rpmh-rsc.c      | 126 +++++++++++++++++++++++++++++++++++++++
> >  2 files changed, 133 insertions(+)
> [...]
> > +static int find_slots(struct tcs_group *tcs, struct tcs_request *msg,
> > +                    int *m, int *n)
> > +{
> > +       int slot, offset;
> > +       int i = 0;
> > +
> > +       /* Find if we already have the msg in our TCS */
> > +       slot = find_match(tcs, msg->payload, msg->num_payload);
> > +       if (slot >= 0)
> > +               goto copy_data;
> > +
> > +       /* Do over, until we can fit the full payload in a TCS */
> > +       do {
> > +               slot = bitmap_find_next_zero_area(tcs->slots, MAX_TCS_SLOTS,
> > +                                                i, msg->num_payload, 0);
> > +               if (slot == MAX_TCS_SLOTS)
> > +                       break;
> > +               i += tcs->ncpt;
> > +       } while (slot + msg->num_payload - 1 >= i);
> > +
> > +       if (slot == MAX_TCS_SLOTS)
> > +               return -ENOMEM;
> > +
> > +copy_data:
> > +       bitmap_set(tcs->slots, slot, msg->num_payload);
> > +       /* Copy the addresses of the resources over to the slots */
> > +       for (i = 0; tcs->cmd_addr && i < msg->num_payload; i++)
>
> I don't think tcs->cmd_addr can be null, can it? Above, find_match()
> is already reaching through cmd_addr with enthusiasm. If kept, it
> could at least be moved outside of the loop.
It would be NULL for ACTIVE_TCS. I can move the check outside the loop.

Thanks,
Lina