Re: [PATCH 1/2] dt-bindings: remoteproc: imx_rproc: Document fsl,startup-delay-ms

[Marek Vasut <marex@denx.de>]

On 7/10/23 14:52, Krzysztof Kozlowski wrote:
> On 10/07/2023 11:18, Marek Vasut wrote:
>> On 7/10/23 10:12, Krzysztof Kozlowski wrote:
>>> On 08/07/2023 01:24, Marek Vasut wrote:
>>>> Document fsl,startup-delay-ms property which indicates how long
>>>> the system software should wait until attempting to communicate
>>>> with the CM firmware. This gives the CM firmware a bit of time
>>>> to boot and get ready for communication.
>>>>
>>>> Signed-off-by: Marek Vasut <marex@denx.de>
>>>> ---
>>>> Cc: Bjorn Andersson <andersson@kernel.org>
>>>> Cc: Conor Dooley <conor+dt@kernel.org>
>>>> Cc: Fabio Estevam <festevam@gmail.com>
>>>> Cc: Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>
>>>> Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
>>>> Cc: NXP Linux Team <linux-imx@nxp.com>
>>>> Cc: Peng Fan <peng.fan@nxp.com>
>>>> Cc: Pengutronix Kernel Team <kernel@pengutronix.de>
>>>> Cc: Rob Herring <robh+dt@kernel.org>
>>>> Cc: Sascha Hauer <s.hauer@pengutronix.de>
>>>> Cc: Shawn Guo <shawnguo@kernel.org>
>>>> Cc: devicetree@vger.kernel.org
>>>> Cc: linux-arm-kernel@lists.infradead.org
>>>> Cc: linux-remoteproc@vger.kernel.org
>>>> ---
>>>>    .../devicetree/bindings/remoteproc/fsl,imx-rproc.yaml        | 5 +++++
>>>>    1 file changed, 5 insertions(+)
>>>>
>>>> diff --git a/Documentation/devicetree/bindings/remoteproc/fsl,imx-rproc.yaml b/Documentation/devicetree/bindings/remoteproc/fsl,imx-rproc.yaml
>>>> index 0c3910f152d1d..c940199ce89df 100644
>>>> --- a/Documentation/devicetree/bindings/remoteproc/fsl,imx-rproc.yaml
>>>> +++ b/Documentation/devicetree/bindings/remoteproc/fsl,imx-rproc.yaml
>>>> @@ -76,6 +76,11 @@ properties:
>>>>          This property is to specify the resource id of the remote processor in SoC
>>>>          which supports SCFW
>>>>    
>>>> +  fsl,startup-delay-ms:
>>>> +    default: 0
>>>> +    description:
>>>> +      CM firmware start up delay.
>>>
>>> I don't see particular improvements from v2 and no responses addressing
>>> my comment:
>>> https://lore.kernel.org/all/20221102112451.128110-2-peng.fan@oss.nxp.com/
>>
>> I wasn't aware of this being submitted before, esp. since I wrote the
>> binding document from scratch. Which comment is not addressed, the type
>> ref is not present and the sentence starts with caps, so what is missing ?
> 
> 
> That the property looks like a hacky solution to some SW problem. Why
> this delay should be different on different boards?

It probably depends more on the CM4 firmware that is being launched. The 
ones I tested were fine with 50..500ms delay, but the delay was always 
needed.

Sure, it is a defect of the NXP provided SDK firmware, but that may not 
be fixable in all cases.