[RFC PATCH v2 00/11] Simple QoS for exynos-bus driver using interconnect

[Chanwoo Choi]

Hi Artur,

I tried to just build this patch on mainline kernel or linux-next.
But, when I applied them, merge conflict happens. You didn't develop
them on latest version. Please rebase them based on latest mainline kernel.

On 19. 9. 20. 오전 10:07, Chanwoo Choi wrote:
> Hi Artur,
> 
> On v1, I mentioned that we need to discuss how to change
> the v2 for this. But, I have not received any reply from you on v1.
> And, without your reply from v1, you just send v2.
> 
> I think that it is not proper development sequence.
> I have spent many times to review your patches
> and also I'll review your patches. You have to take care
> the reply of reviewer and and keep the basic rule
> of mailing contribution for discussion.
> 
> On 19. 9. 19. 오후 11:22, Artur Świgoń wrote:
>> The following patchset adds interconnect[1][2] framework support to the
>> exynos-bus devfreq driver. Extending the devfreq driver with interconnect
>> capabilities started as a response to the issue referenced in [3]. The
>> patches can be subdivided into four logical groups:
>>
>> (a) Refactoring the existing devfreq driver in order to improve readability
>> and accommodate for adding new code (patches 01--04/11).
>>
>> (b) Tweaking the interconnect framework to support the exynos-bus use case
>> (patches 05--07/11). Exporting of_icc_get_from_provider() allows us to
>> avoid hardcoding every single graph edge in the DT or driver source, and
>> relaxing the requirement contained in that function removes the need to
>> provide dummy node IDs in the DT. Adjusting the logic in
>> apply_constraints() (drivers/interconnect/core.c) accounts for the fact
>> that every bus is a separate entity and therefore a separate interconnect
>> provider, albeit constituting a part of a larger hierarchy.
>>
>> (c) Implementing interconnect providers in the exynos-bus devfreq driver
>> and adding required DT properties for one selected platform, namely
>> Exynos4412 (patches 08--09/11). Due to the fact that this aims to be a
>> generic driver for various Exynos SoCs, node IDs are generated dynamically
>> rather than hardcoded. This has been determined to be a simpler approach,
>> but depends on changes described in (b).
>>
>> (d) Implementing a sample interconnect consumer for exynos-mixer targeted
>> at the issue referenced in [3], again with DT info only for Exynos4412
>> (patches 10--11/11).
>>
>> Integration of devfreq and interconnect functionalities is achieved by
>> using dev_pm_qos_*() API[5]. All new code works equally well when
>> CONFIG_INTERCONNECT is 'n' (as in exynos_defconfig) in which case all
>> interconnect API functions are no-ops.
>>
>> This patchset depends on [5].
>>
>> --- Changes since v1 [6]:
>> * Rebase on [4] (coupled regulators).
>> * Rebase on [5] (dev_pm_qos for devfreq).
>> * Use dev_pm_qos_*() API[5] instead of overriding frequency in
>>   exynos_bus_target().
>> * Use IDR for node ID allocation.
>> * Avoid goto in functions extracted in patches 01 & 02 (cf. patch 04).
>> * Reverse order of multiplication and division in
>>   mixer_set_memory_bandwidth() (patch 11) to avoid integer overflow.
>>
>> ---
>> Artur Świgoń
>> Samsung R&D Institute Poland
>> Samsung Electronics
>>
>> ---
>> References:
>> [1] Documentation/interconnect/interconnect.rst
>> [2] Documentation/devicetree/bindings/interconnect/interconnect.txt
>> [3] https://patchwork.kernel.org/patch/10861757/ (original issue)
>> [4] https://patchwork.kernel.org/cover/11083663/ (coupled regulators; merged)
>> [5] https://patchwork.kernel.org/cover/11149497/ (dev_pm_qos for devfreq)
>> [6] https://patchwork.kernel.org/cover/11054417/ (v1 of this RFC)
>>
>> Artur Świgoń (10):
>>   devfreq: exynos-bus: Extract exynos_bus_profile_init()
>>   devfreq: exynos-bus: Extract exynos_bus_profile_init_passive()
>>   devfreq: exynos-bus: Change goto-based logic to if-else logic
>>   devfreq: exynos-bus: Clean up code
>>   interconnect: Export of_icc_get_from_provider()
>>   interconnect: Relax requirement in of_icc_get_from_provider()
>>   interconnect: Relax condition in apply_constraints()
>>   arm: dts: exynos: Add parents and #interconnect-cells to Exynos4412
>>   devfreq: exynos-bus: Add interconnect functionality to exynos-bus
>>   arm: dts: exynos: Add interconnects to Exynos4412 mixer
>>
>> Marek Szyprowski (1):
>>   drm: exynos: mixer: Add interconnect support
>>
>>  .../boot/dts/exynos4412-odroid-common.dtsi    |   1 +
>>  arch/arm/boot/dts/exynos4412.dtsi             |  10 +
>>  drivers/devfreq/exynos-bus.c                  | 319 +++++++++++++-----
>>  drivers/gpu/drm/exynos/exynos_mixer.c         |  71 +++-
>>  drivers/interconnect/core.c                   |  12 +-
>>  include/linux/interconnect-provider.h         |   6 +
>>  6 files changed, 327 insertions(+), 92 deletions(-)
>>
> 
> 


-- 
Best Regards,
Chanwoo Choi
Samsung Electronics