This series reshuffles things around, moving the management of SMD RPM
bus clocks to the interconnect framework where they belong. This helps
us solve a couple of issues:
1. We can work towards unused clk cleanup of RPMCC without worrying
about it killing some NoC bus, resulting in the SoC dying.
Deasserting actually unused RPM clocks (among other things) will
let us achieve "true SoC-wide power collapse states", also known as
VDD_LOW and VDD_MIN.
2. We no longer have to keep tons of quirky bus clock ifs in the icc
driver. You either have a RPM clock and call "rpm set rate" or you
have a single non-RPM clock (like AHB_CLK_SRC) or you don't have any.
3. There's less overhead - instead of going through layers and layers of
the CCF, ratesetting comes down to calling max() and sending a single
RPM message. ICC is very very dynamic so that's a big plus.
The clocks still need to be vaguely described in the clk-smd-rpm driver,
as it gives them an initial kickoff, before actually telling RPM to
enable DVFS scaling. After RPM receives that command, all clocks that
have not been assigned a rate are considered unused and are shut down
in hardware, leading to the same issue as described in point 1.
We can consider marking them __initconst in the future, but this series
is very fat even without that..
Apart from that, it squashes a couple of bugs that really need fixing..
The series is merged through a topic branch to manage the dependencies
between interconnect, Qualcomm clocks and Qualcomm SoC.
Up until now, we've been aggregating the bandwidth values and only
dividing them by the bus width of the source node. This was completely
wrong, as different nodes on a given path may (and usually do) have
varying bus widths. That in turn, resulted in the calculated clock rates
being completely bogus - usually they ended up being much higher, as
NoC_A<->NoC_B links are very wide.
Since we're not using the aggregate bandwidth value for anything other
than clock rate calculations, remodel qcom_icc_bus_aggregate() to
calculate the per-context clock rate for a given provider, taking into
account the bus width of every individual node.
Fixes: 30c8fa3ec6 ("interconnect: qcom: Add MSM8916 interconnect provider driver")
Reported-by: Stephan Gerhold <stephan@gerhold.net>
Reviewed-by: Stephan Gerhold <stephan@gerhold.net>
Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Acked-by: Georgi Djakov <djakov@kernel.org>
Link: https://lore.kernel.org/r/20230526-topic-smd_icc-v7-22-09c78c175546@linaro.org
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Up until now, for some reason we've only been setting bandwidth values
on the active-only context. That pretty much meant that RPM could lift
all votes when entering sleep mode. Or never sleep at all.
That in turn could potentially break things like USB wakeup, as the
connection between APSS and SNoC/PNoC would simply be dead.
Set the values appropriately.
Fixes: 30c8fa3ec6 ("interconnect: qcom: Add MSM8916 interconnect provider driver")
Reviewed-by: Stephan Gerhold <stephan@gerhold.net>
Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Acked-by: Georgi Djakov <djakov@kernel.org>
Link: https://lore.kernel.org/r/20230526-topic-smd_icc-v7-20-09c78c175546@linaro.org
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
SMD RPM only provides two buckets, one each for the active-only and
active-sleep RPM contexts. Use the correct constant to allocate and
operate on them.
This will make the qcom,icc.h header no longer work with this driver,
mostly because.. it was never meant to! The commit that introduced
bucket support to SMD RPM was trying to shove a square into a round
hole and it did not work out very well. That said, there are no
active users of SMD RPM ICC + qcom,icc.h, so that doesn't hurt.
Fixes: dcbce7b0a7 ("interconnect: qcom: icc-rpm: Support multiple buckets")
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Stephan Gerhold <stephan@gerhold.net>
Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Acked-by: Georgi Djakov <djakov@kernel.org>
Link: https://lore.kernel.org/r/20230526-topic-smd_icc-v7-19-09c78c175546@linaro.org
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
The interconnect bus clocks are now handled within the ICC framework.
They still however need to get a kickstart *before* we call
clk_smd_rpm_enable_scaling(), or RPM will assume that they should all
be running at 0 kHz and the system will inevitably die.
Separate them out to ensure such a kickstart can still take place.
As a happy accident, the file got smaller:
Total: Before=41951, After=41555, chg -0.94%
Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Acked-by: Stephen Boyd <sboyd@kernel.org>
Acked-by: Georgi Djakov <djakov@kernel.org>
Link: https://lore.kernel.org/r/20230526-topic-smd_icc-v7-18-09c78c175546@linaro.org
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
The sole purpose of bus clocks that were previously registered with
rpmcc was to convey the aggregated bandwidth to RPM. There's no good
reason to keep them outside the interconnect framework, as it only
adds to the plentiful complexity.
Add the required code to handle these clocks from within SMD RPM ICC.
RPM-owned bus clocks are no longer considered a thing, but sadly we
have to allow for the existence of HLOS-owned bus clocks, as some
(mostly older) SoCs (ab)use these for bus scaling (e.g. MSM8998 and
&mmcc AHB_CLK_SRC).
This in turn is trivially solved with a single *clk, which is filled
and used iff qp.bus_clk_desc is absent and we have a "bus" clock-names
entry in the DT node.
This change should(tm) be fully compatible with all sorts of old
Device Trees as far as the interconnect functionality goes (modulo
abusing bus clock handles or wrongly using the qcom,icc.h binding,
but that's a mistake in and of itself).
Reviewed-by: Stephan Gerhold <stephan@gerhold.net>
Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Acked-by: Georgi Djakov <djakov@kernel.org>
Link: https://lore.kernel.org/r/20230526-topic-smd_icc-v7-17-09c78c175546@linaro.org
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
The downstream kernel employs the concept of "keeping the bus alive"
by voting for the minimum (XO/19.2MHz) rate at all times on certain
(well, most) buses. This is a very important thing to have, as if we
either have a lackluster/wrong DT that doesn't specify a (high enough)
vote on a certain bus, we may lose access to the entire bus altogether.
This is very apparent when we only start introducing interconnect
support on a given platform and haven't yet introduced voting on all
peripherals.
The same can happen if we only have a single driver casting a vote on
a certain bus and that driver exits/crashes/suspends.
The keepalive vote is limited to the ACTIVE bucket, as keeping a
permanent vote on the SLEEP one could prevent the platform from properly
entering low power mode states.
Introduce the very same concept, with a slight twist: the vendor
kernel checks whether the rate is zero before setting the minimum
vote, but that's rather silly, as in doing so we're at the mercy
of CCF. Instead, explicitly clamp the rates to always be >= 19.2 MHz
for providers with keep_alive=true.
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Acked-by: Georgi Djakov <djakov@kernel.org>
Link: https://lore.kernel.org/r/20230526-topic-smd_icc-v7-6-09c78c175546@linaro.org
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
icc_smd_rpm will do bus clock votes itself rather than taking the
unnecessary detour through the clock subsystem. However, it can only
do that after the clocks have been handed off and scaling has been
enabled in the RPM in clk-smd-rpm.
Move the icc_smd_rpm registration from smd-rpm.c to clk-smd-rpm.c
to avoid any possible races. icc_smd_rpm gets the driver data from
the smd-rpm device, so still register the platform device on the
smd-rpm parent device.
Signed-off-by: Stephan Gerhold <stephan@gerhold.net>
[Konrad: remove unrelated cleanups]
Acked-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Acked-by: Georgi Djakov <djakov@kernel.org>
Link: https://lore.kernel.org/r/20230526-topic-smd_icc-v7-5-09c78c175546@linaro.org
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
