* [PATCH] dt-bindings: mmc: Add cap-aggressive-pm property @ 2023-01-29 2:36 Hermes Zhang 2023-01-29 10:58 ` Krzysztof Kozlowski 0 siblings, 1 reply; 5+ messages in thread From: Hermes Zhang @ 2023-01-29 2:36 UTC (permalink / raw) To: Ulf Hansson, Rob Herring, Krzysztof Kozlowski Cc: kernel, Hermes Zhang, linux-mmc, devicetree, linux-kernel This commit add a new property: cap-aggressive-pm to enable the MMC_CAP_AGGRESSIVE_PM feature for (e)MMC/SD power saving. Signed-off-by: Hermes Zhang <chenhuiz@axis.com> --- Documentation/devicetree/bindings/mmc/mmc-controller.yaml | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/Documentation/devicetree/bindings/mmc/mmc-controller.yaml b/Documentation/devicetree/bindings/mmc/mmc-controller.yaml index 86c73fd825fd..7ca674263dba 100644 --- a/Documentation/devicetree/bindings/mmc/mmc-controller.yaml +++ b/Documentation/devicetree/bindings/mmc/mmc-controller.yaml @@ -177,6 +177,11 @@ properties: description: enable SDIO IRQ signalling on this interface + cap-aggressive-pm: + $ref: /schemas/types.yaml#/definitions/flag + description: + enable MMC_CAP_AGGRESSIVE_PM feature + full-pwr-cycle: $ref: /schemas/types.yaml#/definitions/flag description: -- 2.30.2 ^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH] dt-bindings: mmc: Add cap-aggressive-pm property 2023-01-29 2:36 [PATCH] dt-bindings: mmc: Add cap-aggressive-pm property Hermes Zhang @ 2023-01-29 10:58 ` Krzysztof Kozlowski [not found] ` <b125f25d-94c7-dd5b-28d3-3948c36ef4e0@axis.com> 0 siblings, 1 reply; 5+ messages in thread From: Krzysztof Kozlowski @ 2023-01-29 10:58 UTC (permalink / raw) To: Hermes Zhang, Ulf Hansson, Rob Herring, Krzysztof Kozlowski Cc: kernel, linux-mmc, devicetree, linux-kernel On 29/01/2023 03:36, Hermes Zhang wrote: > This commit add a new property: cap-aggressive-pm to enable the Do not use "This commit/patch". https://elixir.bootlin.com/linux/v5.17.1/source/Documentation/process/submitting-patches.rst#L95 > MMC_CAP_AGGRESSIVE_PM feature for (e)MMC/SD power saving. Why this is a property suitable for DT? IOW, why this isn't enabled always? > > Signed-off-by: Hermes Zhang <chenhuiz@axis.com> > --- > Documentation/devicetree/bindings/mmc/mmc-controller.yaml | 5 +++++ > 1 file changed, 5 insertions(+) Best regards, Krzysztof ^ permalink raw reply [flat|nested] 5+ messages in thread
[parent not found: <b125f25d-94c7-dd5b-28d3-3948c36ef4e0@axis.com>]
* Re: [PATCH] dt-bindings: mmc: Add cap-aggressive-pm property [not found] ` <b125f25d-94c7-dd5b-28d3-3948c36ef4e0@axis.com> @ 2023-01-31 16:57 ` Krzysztof Kozlowski 2023-02-02 14:59 ` Ulf Hansson 0 siblings, 1 reply; 5+ messages in thread From: Krzysztof Kozlowski @ 2023-01-31 16:57 UTC (permalink / raw) To: Hermes Zhang, Ulf Hansson, Rob Herring, Krzysztof Kozlowski Cc: kernel, linux-mmc, devicetree, linux-kernel On 30/01/2023 07:54, Hermes Zhang wrote: > On 2023/1/29 18:58, Krzysztof Kozlowski wrote: >> On 29/01/2023 03:36, Hermes Zhang wrote: >>> This commit add a new property: cap-aggressive-pm to enable the >> Do not use "This commit/patch". >> https://elixir.bootlin.com/linux/v5.17.1/source/Documentation/process/submitting-patches.rst#L95 > > Done > >>> MMC_CAP_AGGRESSIVE_PM feature for (e)MMC/SD power saving. >> Why this is a property suitable for DT? IOW, why this isn't enabled always? > > This property will benfit for the power consumption, but it also may > degradation in performance as it will prevent the > > the card from executing internal house-keeping operations in idle mode. > So it's better to config it from DT. Why? DT is not for policy. How you described it, this is policy or system tuning choice thus the job for Linux (OS), not for DT. So I will repeat - why this property fits the purpose of DT (describe the hardware). Best regards, Krzysztof ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] dt-bindings: mmc: Add cap-aggressive-pm property 2023-01-31 16:57 ` Krzysztof Kozlowski @ 2023-02-02 14:59 ` Ulf Hansson 2023-02-02 16:25 ` Krzysztof Kozlowski 0 siblings, 1 reply; 5+ messages in thread From: Ulf Hansson @ 2023-02-02 14:59 UTC (permalink / raw) To: Hermes Zhang, Krzysztof Kozlowski Cc: Rob Herring, Krzysztof Kozlowski, kernel, linux-mmc, devicetree, linux-kernel On Tue, 31 Jan 2023 at 17:57, Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> wrote: > > On 30/01/2023 07:54, Hermes Zhang wrote: > > On 2023/1/29 18:58, Krzysztof Kozlowski wrote: > >> On 29/01/2023 03:36, Hermes Zhang wrote: > >>> This commit add a new property: cap-aggressive-pm to enable the > >> Do not use "This commit/patch". > >> https://elixir.bootlin.com/linux/v5.17.1/source/Documentation/process/submitting-patches.rst#L95 > > > > Done > > > >>> MMC_CAP_AGGRESSIVE_PM feature for (e)MMC/SD power saving. > >> Why this is a property suitable for DT? IOW, why this isn't enabled always? > > > > This property will benfit for the power consumption, but it also may > > degradation in performance as it will prevent the > > > > the card from executing internal house-keeping operations in idle mode. > > So it's better to config it from DT. > > Why? DT is not for policy. How you described it, this is policy or > system tuning choice thus the job for Linux (OS), not for DT. So I will > repeat - why this property fits the purpose of DT (describe the hardware). > I guess the HW perspective here, is that it might not fit all platforms nor the actual eMMC/SD card to support this feature. However, it still seems like a policy rather than a strict HW constraint. Perhaps there is a way to figure out in the host driver, to conditionally set the MMC_CAP_AGGRESSIVE_PM for the host, when needed instead? Kind regards Uffe ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] dt-bindings: mmc: Add cap-aggressive-pm property 2023-02-02 14:59 ` Ulf Hansson @ 2023-02-02 16:25 ` Krzysztof Kozlowski 0 siblings, 0 replies; 5+ messages in thread From: Krzysztof Kozlowski @ 2023-02-02 16:25 UTC (permalink / raw) To: Ulf Hansson, Hermes Zhang Cc: Rob Herring, Krzysztof Kozlowski, kernel, linux-mmc, devicetree, linux-kernel On 02/02/2023 15:59, Ulf Hansson wrote: > On Tue, 31 Jan 2023 at 17:57, Krzysztof Kozlowski > <krzysztof.kozlowski@linaro.org> wrote: >> >> On 30/01/2023 07:54, Hermes Zhang wrote: >>> On 2023/1/29 18:58, Krzysztof Kozlowski wrote: >>>> On 29/01/2023 03:36, Hermes Zhang wrote: >>>>> This commit add a new property: cap-aggressive-pm to enable the >>>> Do not use "This commit/patch". >>>> https://elixir.bootlin.com/linux/v5.17.1/source/Documentation/process/submitting-patches.rst#L95 >>> >>> Done >>> >>>>> MMC_CAP_AGGRESSIVE_PM feature for (e)MMC/SD power saving. >>>> Why this is a property suitable for DT? IOW, why this isn't enabled always? >>> >>> This property will benfit for the power consumption, but it also may >>> degradation in performance as it will prevent the >>> >>> the card from executing internal house-keeping operations in idle mode. >>> So it's better to config it from DT. >> >> Why? DT is not for policy. How you described it, this is policy or >> system tuning choice thus the job for Linux (OS), not for DT. So I will >> repeat - why this property fits the purpose of DT (describe the hardware). >> > > I guess the HW perspective here, is that it might not fit all > platforms nor the actual eMMC/SD card to support this feature. > However, it still seems like a policy rather than a strict HW > constraint. > > Perhaps there is a way to figure out in the host driver, to > conditionally set the MMC_CAP_AGGRESSIVE_PM for the host, when needed > instead? What also worries me is that there is no user of this property: no DTS, no driver, so it is tricky to deduct out when it is applicable. Anyway things which might be obvious for the submitter, might not be for the reviewer, thus I would really like to see justification why different boards (or memories) need this property. Best regards, Krzysztof ^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2023-02-02 16:25 UTC | newest]
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2023-01-29 2:36 [PATCH] dt-bindings: mmc: Add cap-aggressive-pm property Hermes Zhang
2023-01-29 10:58 ` Krzysztof Kozlowski
[not found] ` <b125f25d-94c7-dd5b-28d3-3948c36ef4e0@axis.com>
2023-01-31 16:57 ` Krzysztof Kozlowski
2023-02-02 14:59 ` Ulf Hansson
2023-02-02 16:25 ` Krzysztof Kozlowski
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