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author | Viresh Kumar <viresh.kumar@linaro.org> | 2023-10-12 15:45:21 +0530 |
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committer | Viresh Kumar <viresh.kumar@linaro.org> | 2023-11-28 16:03:15 +0530 |
commit | 6d366d0e544676bf608769b9520644e3f654ff99 (patch) | |
tree | 446c1784664f72c1774e17c80275e9433ace1cec /drivers/opp | |
parent | 073d3d2ca7d462afc8159ca0175675b9b7b4f162 (diff) | |
download | lwn-6d366d0e544676bf608769b9520644e3f654ff99.tar.gz lwn-6d366d0e544676bf608769b9520644e3f654ff99.zip |
OPP: Use _set_opp_level() for single genpd case
There are two genpd (as required-opp) cases that we need to handle,
devices with a single genpd and ones with multiple genpds.
The multiple genpds case is clear, where the OPP core calls
dev_pm_domain_attach_by_name() for them and uses the virtual devices
returned by this helper to call dev_pm_domain_set_performance_state()
later to change the performance state.
The single genpd case however requires special handling as we need to
use the same `dev` structure (instead of a virtual one provided by genpd
core) for setting the performance state via
dev_pm_domain_set_performance_state().
As we move towards more generic code to take care of the required OPPs,
where we will recursively call dev_pm_opp_set_opp() for all the required
OPPs, the above special case becomes a problem.
It doesn't make sense for a device's DT entry to have both "opp-level"
and single "required-opps" entry pointing to a genpd's OPP, as that
would make the OPP core call dev_pm_domain_set_performance_state() for
two different values for the same device structure. And so we can reuse
the 'opp->level" field in such a case and call _set_opp_level() for the
device.
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Tested-by: Stephan Gerhold <stephan.gerhold@kernkonzept.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Diffstat (limited to 'drivers/opp')
-rw-r--r-- | drivers/opp/core.c | 6 | ||||
-rw-r--r-- | drivers/opp/of.c | 31 |
2 files changed, 32 insertions, 5 deletions
diff --git a/drivers/opp/core.c b/drivers/opp/core.c index f2e2aa07b431..aeb216f7e978 100644 --- a/drivers/opp/core.c +++ b/drivers/opp/core.c @@ -1088,10 +1088,12 @@ static int _opp_set_required_opps_generic(struct device *dev, static int _opp_set_required_opps_genpd(struct device *dev, struct opp_table *opp_table, struct dev_pm_opp *opp, bool scaling_down) { - struct device **genpd_virt_devs = - opp_table->genpd_virt_devs ? opp_table->genpd_virt_devs : &dev; + struct device **genpd_virt_devs = opp_table->genpd_virt_devs; int index, target, delta, ret; + if (!genpd_virt_devs) + return 0; + /* Scaling up? Set required OPPs in normal order, else reverse */ if (!scaling_down) { index = 0; diff --git a/drivers/opp/of.c b/drivers/opp/of.c index 85fad7ca0007..4cdeeab5ceee 100644 --- a/drivers/opp/of.c +++ b/drivers/opp/of.c @@ -296,7 +296,7 @@ void _of_clear_opp(struct opp_table *opp_table, struct dev_pm_opp *opp) of_node_put(opp->np); } -static int _link_required_opps(struct dev_pm_opp *opp, +static int _link_required_opps(struct dev_pm_opp *opp, struct opp_table *opp_table, struct opp_table *required_table, int index) { struct device_node *np; @@ -314,6 +314,31 @@ static int _link_required_opps(struct dev_pm_opp *opp, return -ENODEV; } + /* + * There are two genpd (as required-opp) cases that we need to handle, + * devices with a single genpd and ones with multiple genpds. + * + * The single genpd case requires special handling as we need to use the + * same `dev` structure (instead of a virtual one provided by genpd + * core) for setting the performance state. + * + * It doesn't make sense for a device's DT entry to have both + * "opp-level" and single "required-opps" entry pointing to a genpd's + * OPP, as that would make the OPP core call + * dev_pm_domain_set_performance_state() for two different values for + * the same device structure. Lets treat single genpd configuration as a + * case where the OPP's level is directly available without required-opp + * link in the DT. + * + * Just update the `level` with the right value, which + * dev_pm_opp_set_opp() will take care of in the normal path itself. + */ + if (required_table->is_genpd && opp_table->required_opp_count == 1 && + !opp_table->genpd_virt_devs) { + if (!WARN_ON(opp->level != OPP_LEVEL_UNSET)) + opp->level = opp->required_opps[0]->level; + } + return 0; } @@ -338,7 +363,7 @@ static int _of_opp_alloc_required_opps(struct opp_table *opp_table, if (IS_ERR_OR_NULL(required_table)) continue; - ret = _link_required_opps(opp, required_table, i); + ret = _link_required_opps(opp, opp_table, required_table, i); if (ret) goto free_required_opps; } @@ -359,7 +384,7 @@ static int lazy_link_required_opps(struct opp_table *opp_table, int ret; list_for_each_entry(opp, &opp_table->opp_list, node) { - ret = _link_required_opps(opp, new_table, index); + ret = _link_required_opps(opp, opp_table, new_table, index); if (ret) return ret; } |