On 03/07/2021 05:54, Bjorn Andersson wrote:
The general expectation is that powering on a power-domain should make
the power domain deliver some power, and if a specific performace 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 turn 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>
---
Resending because the hunk in rpmhpd_update_level_mapping() was left in the
index.
So, colleagues, what is the fate of this patch? Is it going to be
applied? Or we agree that current approach (power_on +
set_performance_state) is the expected behaviour? My patches on gdsc
rework depend on this patch, but I can rework in them in favour of
required-opp approach.
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 fa209b479ab3..76ea6b053ef0 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;
@@ -385,13 +387,13 @@ 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;
@@ -436,6 +438,10 @@ 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;
@@ -472,6 +478,10 @@ 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 non-zero corner */
+ if (!rpmhpd->enable_corner)
+ rpmhpd->enable_corner = i;
+
/*
* The AUX data may be zero padded. These 0 valued entries at
* the end of the map must be ignored.
--
With best wishes
Dmitry
