On Tue, 5 Oct 2021 at 05:35, Bjorn Andersson <bjorn.andersson@xxxxxxxxxx> wrote:
>
> The general expectation is that powering on a power-domain should make
> the power domain deliver some power, and if a specific performance state
> is needed further requests has to be made.
>
> But in contrast with other power-domain implementations (e.g. rpmpd) the
> RPMh does not have an interface to enable the power, so the driver has
> to vote for a particular corner (performance level) in rpmh_power_on().
>
> But the corner is never initialized, so a typical request to simply
> enable the power domain would not actually turn on the hardware. Further
> more, when no more clients vote for a performance state (i.e. the
> aggregated vote is 0) the power domain would be turned off.
>
> Fix both of these issues by always voting for a corner with non-zero
> value, when the power domain is enabled.
>
> The tracking of the lowest non-zero corner is performed to handle the
> corner case if there's ever a domain with a non-zero lowest corner, in
> which case both rpmh_power_on() and rpmh_rpmhpd_set_performance_state()
> would be allowed to use this lowest corner.
>
> Fixes: 279b7e8a62cc ("soc: qcom: rpmhpd: Add RPMh power domain driver")
> Signed-off-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
Looks reasonable to me!
Reviewed-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
Kind regards
Uffe
> ---
>
> Changes since v2:
> - Fixed two spelling mistakes in the commit message
> - Changed the last hunk to search for first non-zero level, rather than the
> first non-zero index (i.e. 1)
>
> drivers/soc/qcom/rpmhpd.c | 18 ++++++++++++++----
> 1 file changed, 14 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/soc/qcom/rpmhpd.c b/drivers/soc/qcom/rpmhpd.c
> index e280a8194725..0ca77ed22c6c 100644
> --- a/drivers/soc/qcom/rpmhpd.c
> +++ b/drivers/soc/qcom/rpmhpd.c
> @@ -30,6 +30,7 @@
> * @active_only: True if it represents an Active only peer
> * @corner: current corner
> * @active_corner: current active corner
> + * @enable_corner: lowest non-zero corner
> * @level: An array of level (vlvl) to corner (hlvl) mappings
> * derived from cmd-db
> * @level_count: Number of levels supported by the power domain. max
> @@ -47,6 +48,7 @@ struct rpmhpd {
> const bool active_only;
> unsigned int corner;
> unsigned int active_corner;
> + unsigned int enable_corner;
> u32 level[RPMH_ARC_MAX_LEVELS];
> size_t level_count;
> bool enabled;
> @@ -401,13 +403,13 @@ static int rpmhpd_aggregate_corner(struct rpmhpd *pd, unsigned int corner)
> static int rpmhpd_power_on(struct generic_pm_domain *domain)
> {
> struct rpmhpd *pd = domain_to_rpmhpd(domain);
> - int ret = 0;
> + unsigned int corner;
> + int ret;
>
> mutex_lock(&rpmhpd_lock);
>
> - if (pd->corner)
> - ret = rpmhpd_aggregate_corner(pd, pd->corner);
> -
> + corner = max(pd->corner, pd->enable_corner);
> + ret = rpmhpd_aggregate_corner(pd, corner);
> if (!ret)
> pd->enabled = true;
>
> @@ -452,6 +454,10 @@ static int rpmhpd_set_performance_state(struct generic_pm_domain *domain,
> i--;
>
> if (pd->enabled) {
> + /* Ensure that the domain isn't turn off */
> + if (i < pd->enable_corner)
> + i = pd->enable_corner;
> +
> ret = rpmhpd_aggregate_corner(pd, i);
> if (ret)
> goto out;
> @@ -488,6 +494,10 @@ static int rpmhpd_update_level_mapping(struct rpmhpd *rpmhpd)
> for (i = 0; i < rpmhpd->level_count; i++) {
> rpmhpd->level[i] = buf[i];
>
> + /* Remember the first corner with non-zero level */
> + if (!rpmhpd->level[rpmhpd->enable_corner] && rpmhpd->level[i])
> + rpmhpd->enable_corner = i;
> +
> /*
> * The AUX data may be zero padded. These 0 valued entries at
> * the end of the map must be ignored.
> --
> 2.29.2
>
