linux-stable.git/drivers/opp/core.c, branch v6.6.2

OPP: Fix passing 0 to PTR_ERR in _opp_attach_genpd()

2023-07-24T08:01:25+00:00

If dev_pm_domain_attach_by_name() returns NULL, then 0 will be passed to
PTR_ERR() as reported by the smatch warning below:

drivers/opp/core.c:2456 _opp_attach_genpd() warn: passing zero to 'PTR_ERR'

Fix it by checking for the non-NULL virt_dev pointer before passing it to
PTR_ERR. Otherwise return -ENODEV.

Fixes: 4ea9496cbc95 ("opp: Fix error check in dev_pm_opp_attach_genpd()")
Signed-off-by: Manivannan Sadhasivam 
Signed-off-by: Viresh Kumar

OPP: Fix potential null ptr dereference in dev_pm_opp_get_required_pstate()

2023-07-24T08:01:17+00:00

"opp" pointer is dereferenced before the IS_ERR_OR_NULL() check. Fix it by
removing the dereference to cache opp_table and dereference it directly
where opp_table is used.

This fixes the following smatch warning:

drivers/opp/core.c:232 dev_pm_opp_get_required_pstate() warn: variable
dereferenced before IS_ERR check 'opp' (see line 230)

Fixes: 84cb7ff35fcf ("OPP: pstate is only valid for genpd OPP tables")
Signed-off-by: Manivannan Sadhasivam 
Signed-off-by: Viresh Kumar

OPP: Reuse dev_pm_opp_get_freq_indexed()

2023-07-24T07:57:12+00:00

Reuse dev_pm_opp_get_freq_indexed() from dev_pm_opp_get_freq().

Signed-off-by: Viresh Kumar 
Acked-by: Manivannan Sadhasivam

OPP: Update _read_freq() to return the correct frequency

2023-07-24T07:57:03+00:00

Now that we support finding indexed frequencies, lets update
_read_freq() to return the right one.

Signed-off-by: Viresh Kumar 
Acked-by: Manivannan Sadhasivam

OPP: Add dev_pm_opp_find_freq_exact_indexed()

2023-07-24T07:52:39+00:00

The indexed version of the API is added for other floor and ceil, add
the same for exact as well for completeness.

Signed-off-by: Viresh Kumar

OPP: Introduce dev_pm_opp_get_freq_indexed() API

2023-07-24T07:52:39+00:00

In the case of devices with multiple clocks, drivers need to specify the
frequency index for the OPP framework to get the specific frequency within
the required OPP. So let's introduce the dev_pm_opp_get_freq_indexed() API
accepting the frequency index as an argument.

Signed-off-by: Manivannan Sadhasivam 
[ Viresh: Fixed potential access to NULL opp pointer ]
Signed-off-by: Viresh Kumar

OPP: Introduce dev_pm_opp_find_freq_{ceil/floor}_indexed() APIs

2023-07-21T09:38:27+00:00

In the case of devices with multiple clocks, drivers need to specify the
clock index for the OPP framework to find the OPP corresponding to the
floor/ceil of the supplied frequency. So let's introduce the two new APIs
accepting the clock index as an argument.

These APIs use the exising _find_key_ceil() helper by supplying the clock
index to it.

Signed-off-by: Manivannan Sadhasivam 
[ Viresh: Rearranged definitions in pm_opp.h ]
Signed-off-by: Viresh Kumar

OPP: Simplify the over-designed pstate <-> level dance

2023-06-19T04:20:09+00:00

While adding support for "performance states" in the OPP and genpd core,
it was decided to set the `pstate` field via genpd's
pm_genpd_opp_to_performance_state() helper, to allow platforms to set
`pstate` even if they don't have a corresponding `level` field in the DT
OPP tables (More details are present in commit 6e41766a6a50 ("PM /
Domain: Implement of_genpd_opp_to_performance_state()")).

Revisiting that five years later clearly suggests that it was
over-designed as all current users are eventually using the `level`
value only.

The previous commit already added necessary checks to make sure pstate
is only used for genpd tables. Lets now simplify this a little, and use
`level` directly and remove `pstate` field altogether.

Suggested-by: Ulf Hansson 
Signed-off-by: Viresh Kumar 
Reviewed-by: Ulf Hansson

OPP: pstate is only valid for genpd OPP tables

2023-06-19T04:20:02+00:00

It is not very clear right now that the `pstate` field is only valid for
genpd OPP tables and not consumer tables. And there is no checking for
the same at various places.

Add checks in place to verify that and make it clear to the reader.

Signed-off-by: Viresh Kumar 
Reviewed-by: Ulf Hansson 
Reviewed-by: Bjorn Andersson 
Tested-by: Bjorn Andersson

OPP: don't drop performance constraint on OPP table removal

2023-06-14T09:24:01+00:00

This code was added (long back) by commit 009acd196fc8 ("PM / OPP:
Support updating performance state of device's power domain") and at
that time the `opp->pstate` field was used to store the performance
state required by a device's OPP.

Over time that changed and the `->pstate` field is now used only for
genpd devices and consumer devices access that via the required-opps
instead.

Because of all these changes, _opp_table_kref_release() now drops the
constraint only when the genpd's OPP table gets freed and not the
device's. Which is definitely not what we wanted. And dropping the
constraint doesn't have much meaning as the genpd itself is going away.

Moreover, if we want to drop constraints here, then just dropping the
performance constraint alone isn't sufficient as there are other
resource constraints like clk, regulator, etc. too, which must be
handled.

Probably the right thing to do here is to leave this decision to the
consumers, which can call `dev_pm_opp_set_rate(dev, 0)` or similar APIs
to drop all constraints properly. Which many of the consumers already
do.

Remove the special code, which is broken anyway.

Signed-off-by: Viresh Kumar 
Reviewed-by: Ulf Hansson