[v6,0/3] DCMI set minimum cpufreq requirement

Message

Benjamin GAIGNARD July 1, 2020, 12:59 p.m. UTC

This series allow to STM32 camera interface (DCMI) to require a minimum
frequency to the CPUs before start streaming frames from the sensor.
The minimum frequency requirement is provided in the devide-tree node.

Setting a minimum frequency for the CPUs is needed to ensure a quick handling
of the interrupts between two sensor frames and avoid dropping half of them.

version 6:
- come back to version 4 and follow Valentin's suggestions about notifier

version 5:
- add a mutex to protect dcmi_irq_notifier_notify()
- register notifier a probe time

version 4:
- simplify irq affinity handling by using only dcmi_irq_notifier_notify() 

version 3:
- add a cpumask field to track boosted CPUs
- add irq_affinity_notify callback
- protect cpumask field with a mutex 

Benjamin Gaignard (3):
  dt-bindings: media: stm32-dcmi: Add DCMI min frequency property
  media: stm32-dcmi: Set minimum cpufreq requirement
  ARM: dts: stm32: Set DCMI frequency requirement for stm32mp15x

 .../devicetree/bindings/media/st,stm32-dcmi.yaml   |   8 ++
 arch/arm/boot/dts/stm32mp151.dtsi                  |   1 +
 drivers/media/platform/stm32/stm32-dcmi.c          | 138 +++++++++++++++++++--
 3 files changed, 139 insertions(+), 8 deletions(-)

Comments

Benjamin GAIGNARD July 1, 2020, 1:02 p.m. UTC | #1

On 7/1/20 2:59 PM, Benjamin Gaignard wrote:
> This series allow to STM32 camera interface (DCMI) to require a minimum
> frequency to the CPUs before start streaming frames from the sensor.
> The minimum frequency requirement is provided in the devide-tree node.
>
> Setting a minimum frequency for the CPUs is needed to ensure a quick handling
> of the interrupts between two sensor frames and avoid dropping half of them.
Please forget this version, the incoming version 7 should have fix your 
remarks.

Sorry,
Benjamin
> version 6:
> - come back to version 4 and follow Valentin's suggestions about notifier
>
> version 5:
> - add a mutex to protect dcmi_irq_notifier_notify()
> - register notifier a probe time
>
> version 4:
> - simplify irq affinity handling by using only dcmi_irq_notifier_notify()
>
> version 3:
> - add a cpumask field to track boosted CPUs
> - add irq_affinity_notify callback
> - protect cpumask field with a mutex
>
> Benjamin Gaignard (3):
>    dt-bindings: media: stm32-dcmi: Add DCMI min frequency property
>    media: stm32-dcmi: Set minimum cpufreq requirement
>    ARM: dts: stm32: Set DCMI frequency requirement for stm32mp15x
>
>   .../devicetree/bindings/media/st,stm32-dcmi.yaml   |   8 ++
>   arch/arm/boot/dts/stm32mp151.dtsi                  |   1 +
>   drivers/media/platform/stm32/stm32-dcmi.c          | 138 +++++++++++++++++++--
>   3 files changed, 139 insertions(+), 8 deletions(-)
>