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[v5,00/10] The great interconnecification fixation

Message ID 20230217-topic-icc-fixes-v5-v5-0-c9a550f9fdb9@linaro.org (mailing list archive)
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Series The great interconnecification fixation | expand

Message

Konrad Dybcio Feb. 17, 2023, 10:46 a.m. UTC 
Hi!

v4 -> v5 changelog:
- Previously the "Always set QoS params on QNoC" contained part of what
  should have been included in "make QoS INVALID default".. (very bad)
  Fix it!

- Drop negative offset and keep_alive, they will be resubmitted with new
  icc driver submissions

- use b4 this time.. hopefully the series gets to everybody now

Link to v4: https://lore.kernel.org/linux-arm-msm/20230214143720.2416762-1-konrad.dybcio@linaro.org/

v3 -> v4 changelog:
- Drop "Always set QoS params on QNoC", it only causes issues.. this
  can be investigated another day, as it's not necessary for operation

- Drop "Add a way to always set QoS registers", same as /\

- Add a way (and use it) to have no bus_clocks (the ones we set rate on),
  as at least msm8996 has a bus (A0NoC) that doesn't have any and does
  all the scaling through RPM requests

- Promote 8996 icc to core_initcall

- Introduce keep_alive (see patch [11/12]) (important!, will be used by at least 6375)

- Allow negative QoS offsets in preparation for introducing 8998 icc [12/12]

Link to v3: https://lore.kernel.org/linux-arm-msm/20230116132152.405535-1-konrad.dybcio@linaro.org/

v2 -> v3 changelog:
- Drop "Don't set QoS params before non-zero bw is requested"

- Rebase on next

- [1/9] ("..make QoS INVALID default.."): remove unused define for
  MODE_INVALID_VAL

- Pick up tags

v1 -> v2 changelog:
- reorder "make QoS INVALID default", makes more sense to have it
  before "Always set QoS params on QNoC"

- Limit ap_owned-independent QoS setting to QNoC only

- Add new patches for handling the 8996-and-friends clocks situation
  and optional BIMC regardless-of-ap_owned QoS programming

[1] https://lore.kernel.org/linux-arm-msm/14e06574-f95e-8960-0243-8c95a1c294e9@linaro.org/T/#m056692bea71d4c272968d5e07afbd9eb07a88123
[2] https://lore.kernel.org/linux-arm-msm/20230110132202.956619-1-konrad.dybcio@linaro.org/

This series grew quite a bit bigger than the previous [1] attempt, so
I decided to also add a cover letter.

Link to v2: [2]

It addresses a few things that were not quite right:

- Setting QoS params before a "real" (non-zero) bandwidth request
  makes little sense (since there's no data supposed to flow through
  the bus, why would the QoS matter) and (at least newer) downstream
  prevents that from happening. Do the same in Patch 1.

- QNoC type buses expect to always have their QoS registers set as long
  as there's a non-INVALID QoS mode set; ap_owned is not really a thing
  on these anymore, Patch 3 handles that.

- The recent MSM8996 boot fix was done quickly and not quite properly,
  leading to possibly setting the aggregate bus rate on "normal"
  hardware interface clocks; this series handles that by limiting the
  number of bus_clocks to 2 (which is the maximum that makes sense,
  anyway) and handling the rest as "intf_clocks", which are required
  to access the   hardware at the other end. Patches 5-8 take care of
  that and Patch 10 reverts the _optional moniker in clk_get_ to make
  sure we always have the bus scaling clocks, as they're well, kind
  of important