Re: [PATCH V2 2/3] soc: qcom: boot_stat: Add Driver Support for Boot Stats

[Souradeep Chowdhury]

On 4/12/2023 1:51 PM, Krzysztof Kozlowski wrote:
> On 07/04/2023 16:04, Souradeep Chowdhury wrote:
> > All of Qualcomm's proprietary Android boot-loaders capture boot time
> > stats, like the time when the bootloader started execution and at what
> > point the bootloader handed over control to the kernel etc. in the IMEM
> > region. This information is captured in a specific format by this driver
> > by mapping a structure to the IMEM memory region and then accessing the
> > members of the structure to print the information. This information is
> > useful in verifying if the existing boot KPIs have regressed or not.
> > A sample log in SM8450(waipio) device is as follows:-
>
>
> > +
> > +static int boot_stats_probe(struct platform_device *pdev)
> > +{
> > +	struct device_node *np_mpm2;
> > +	struct device *boot_stat = &pdev->dev;
> > +
> > +	boot_stats = of_iomap(boot_stat->of_node->child, 0);
> > +	if (!boot_stats)
> > +		return dev_err_probe(&pdev->dev, -ENOMEM,
> > +					"failed to map imem region\n");
> > +
> > +	np_mpm2 = of_find_compatible_node(NULL, NULL,
> > +					  "qcom,mpm2-sleep-counter");
>
> This is undocumented and non-existing compatible. No, we cannot take this.
>
> Also, referencing other nodes should be with phandles, not compatibles.

Ack. This will be dropped in the next version as we are not printing the
current kernel timestamp.

> Best regards,
> Krzysztof