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SubjectRe: [PATCH v4 00/12] The great interconnecification fixation
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On 14/02/2023 17:27, Konrad Dybcio wrote:
> +CC Georgi, linux-pm, linux-kernel (thanks git send-email for not including these)

Time to switch to b4 prep ;-)

>
> On 14.02.2023 15:37, Konrad Dybcio wrote:
>> Hi!
>>
>> 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 ;)
>>
>> - Similarly to QNoC, BIMC on "newer" (which can be loosely approximated
>> by "new enough" == "has only BIMC and QNoC hosts") SoCs expects to
>> always receive QoS programming, whereas BIMC on "older" SoCs cries
>> like a wild boar and crashes the platform when trying to do so
>> unconditionally. Patch 9 adds a way to take care of that for newer
>> SoCs (like SM6375)
>>
>> - QoS mode INVALID was assumed by developers before to be the default
>> ("I didn't specify any QoS settings, so the driver can't assume I
>> did.. right? right!?" - wrong, partial struct initialization led to
>> 0 being set and 0 corresponded to QoS mode FIXED). Make it so, as
>> that's the logical choice. This allows the "Always set QoS params
>> on QNoC" patch to work without setting tons of what-should-
>> -obviously-be-the-default values everywhere, as well as fixes older
>> drivers that set ap_owned = true but left the QoS mode field unset.
>> Patch 2 cleans that up.
>>
>> - Some nodes are physically connected over more than one channel
>> (usually DDR or other high-throughput paths). Patch 4 allows that
>> to be reflected in calculations. This will be required for at least
>> MSM8998 and SM6375 (which will be submitted soon after this lands)
>>
>>
>> Konrad Dybcio (12):
>> interconnect: qcom: rpm: make QoS INVALID default, separate out driver
>> data
>> interconnect: qcom: rpm: Add support for specifying channel num
>> interconnect: qcom: Sort kerneldoc entries
>> interconnect: qcom: rpm: Rename icc desc clocks to bus_blocks
>> interconnect: qcom: rpm: Rename icc provider num_clocks to
>> num_bus_clocks
>> interconnect: qcom: rpm: Handle interface clocks
>> interconnect: qcom: icc-rpm: Allow negative num_bus_clocks
>> interconnect: qcom: msm8996: Specify no bus clock scaling on A0NoC
>> interconnect: qcom: rpm: Don't use clk_get_optional for bus clocks
>> anymore
>> interconnect: qcom: msm8996: Promote to core_initcall
>> interconnect: qcom: icc-rpm: Introduce keep_alive
>> interconnect: qcom: icc-rpm: Allow negative QoS offset
>>
>> drivers/interconnect/qcom/icc-rpm.c | 101 ++++++++++++++++++++--------
>> drivers/interconnect/qcom/icc-rpm.h | 41 +++++++----
>> drivers/interconnect/qcom/msm8996.c | 35 ++++++----
>> drivers/interconnect/qcom/sdm660.c | 16 ++---
>> 4 files changed, 126 insertions(+), 67 deletions(-)
>>

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