Re: [PATCH v5 06/17] soc: qcom: Add Qualcomm APSS minidump kernel driver

[Mukesh Ojha <quic_mojha@quicinc.com>]

On 9/12/2023 3:24 PM, Krzysztof Kozlowski wrote:
> On 12/09/2023 11:26, Mukesh Ojha wrote:
>>>
>>>> +		return -EINVAL;
>>>> +	}
>>>> +
>>>> +	mutex_init(&md->md_lock);
>>>> +	ret = qcom_apss_md_table_init(md, &mdgtoc->subsystems[MINIDUMP_APSS_DESC]);
>>>> +	if (ret) {
>>>> +		dev_err(md->dev, "apss minidump initialization failed: %d\n", ret);
>>>> +		return ret;
>>>> +	}
>>>> +
>>>> +	/* First entry would be ELF header */
>>>> +	ret = qcom_md_add_elfheader(md);
>>>> +	if (ret) {
>>>> +		dev_err(md->dev, "Failed to add elf header: %d\n", ret);
>>>> +		memset(md->apss_data->md_ss_toc, 0, sizeof(struct minidump_subsystem));
>>>
>>> Why do you need it?
>>
>> Earlier, i got comment about clearing the SS TOC(subsystem table of
>> content) which is shared with other SS and it will have stale values.
> 
> OK, but then the entire code is poorly readable. First, any cleanup of
> qcom_apss_md_table_init() should be named similarly, e.g.
> qcom_apss_md_table_clean() or qcom_apss_md_table_exit() or whatever
> seems feasible.

ACK on this.

> 
> Second, shouldn't writing to shared memory be the last step? Step which
> cannot fail and there is no cleanup afterwards (like
> platform_set_drvdata)? I don't enjoy looking at this interface...

It can be done, if i shift adding elf header as first thing to first
caller of qcom_minidump_region_register() but then i would have to 
remove qcom_ramoops_minidump() from this probe in 11/17 patch.

-Mukesh
> 
> 
> 
> Best regards,
> Krzysztof
>