lkml.org 
[lkml]   [2020]   [Jun]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [RFC PATCH v5 0/6] Exynos: Simple QoS for exynos-bus using interconnect
From
Date
Cc: Rob, devicetree ML

On 29.05.2020 18:31, Sylwester Nawrocki wrote:
> This patchset adds interconnect API support for the Exynos SoC "samsung,
> exynos-bus" compatible devices, which already have their corresponding
> exynos-bus driver in the devfreq subsystem. Complementing the devfreq driver
> with an interconnect functionality allows to ensure the QoS requirements
> of devices accessing the system memory (e.g. video processing devices)
> are fulfilled and to avoid issues like the one discussed in thread [1].
>
> This patch series depends on 3 patches from Artur for the interconnect API
> [2], which introduce following changes:
>
> - exporting of_icc_get_from_provider() to avoid hard coding every graph
> edge in the DT or driver source,
> - relaxing the requirement on #interconnect-cells, so there is no need
> to provide dummy node IDs in the DT,
> - adding new field in struct icc_provider to explicitly allow configuring
> node pairs from two different providers.
>
> This series adds implementation of interconnect provider per each "samsung,
> exynos-bus" compatible DT node, with one interconnect node per provider.
> The interconnect code which was previously added as a part of the devfreq
> driver has been converted to a separate platform driver. In the devfreq
> a corresponding virtual child platform device is registered. Integration
> of devfreq and interconnect frameworks is achieved through the PM QoS API.
>
> A sample interconnect consumer for exynos-mixer is added in patches 5/6,
> 6/6, it is currently added only for exynos4412 and allows to address the
> mixer DMA underrun error issues [1].
>
> The series has been tested on Odroid U3 board. It is based on icc-next
> branch with devfreq-next branch merged and patches [2] applied.
>
> --
> Regards,
> Sylwester
>
> --
> Changes since v3 [3] (v4 skipped to align with patchset [1]), detailed
> changes are listed at each patch:
> - conversion to a separate interconnect (platform) driver,
> - an update of the DT binding documenting new optional properties:
> #interconnect-cells, samsung,interconnect-parent in "samsung,exynos-bus"
> nodes,
> - new DT properties added to the SoC, rather than to the board specific
> files.
>
> Changes since v2 [5]:
> - Use icc_std_aggregate().
> - Implement a different modification of apply_constraints() in
> drivers/interconnect/core.c (patch 03).
> - Use 'exynos,interconnect-parent-node' in the DT instead of
> 'devfreq'/'parent', depending on the bus.
> - Rebase on DT patches that deprecate the 'devfreq' DT property.
> - Improve error handling, including freeing generated IDs on failure.
> - Remove exynos_bus_icc_connect() and add exynos_bus_icc_get_parent().
>
> Changes since v1 [4]:
> - Rebase on coupled regulators patches.
> - Use dev_pm_qos_*() API instead of overriding frequency in
> exynos_bus_target().
> - Use IDR for node ID allocation.
> - Reverse order of multiplication and division in
> mixer_set_memory_bandwidth() (patch 07) to avoid integer overflow.
>
>
> References:
> [1] https://patchwork.kernel.org/patch/10861757/ (original issue)
> [2] https://www.spinics.net/lists/linux-samsung-soc/msg70014.html
> [3] https://lore.kernel.org/linux-pm/20191220115653.6487-1-a.swigon@samsung.com
> [4] https://patchwork.kernel.org/cover/11054417/ (v1 of this RFC)
> [5] https://patchwork.kernel.org/cover/11152595/ (v2 of this RFC)
>
>
> Artur Świgoń (1):
> ARM: dts: exynos: Add interconnects to Exynos4412 mixer
>
> Marek Szyprowski (1):
> drm: exynos: mixer: Add interconnect support
>
> Sylwester Nawrocki (4):
> dt-bindings: exynos-bus: Add documentation for interconnect properties
> interconnect: Add generic interconnect driver for Exynos SoCs
> PM / devfreq: exynos-bus: Add registration of interconnect child
> device
> ARM: dts: exynos: Add interconnect properties to Exynos4412 bus nodes
>
> .../devicetree/bindings/devfreq/exynos-bus.txt | 15 +-
> arch/arm/boot/dts/exynos4412.dtsi | 6 +
> drivers/devfreq/exynos-bus.c | 17 ++
> drivers/gpu/drm/exynos/exynos_mixer.c | 73 +++++++-
> drivers/interconnect/Kconfig | 1 +
> drivers/interconnect/Makefile | 1 +
> drivers/interconnect/exynos/Kconfig | 6 +
> drivers/interconnect/exynos/Makefile | 4 +
> drivers/interconnect/exynos/exynos.c | 185 +++++++++++++++++++++
> 9 files changed, 301 insertions(+), 7 deletions(-)
> create mode 100644 drivers/interconnect/exynos/Kconfig
> create mode 100644 drivers/interconnect/exynos/Makefile
> create mode 100644 drivers/interconnect/exynos/exynos.c

\
 
 \ /
  Last update: 2020-06-01 10:17    [W:0.194 / U:4.472 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site