On 22/03/2023 14:54, Souradeep Chowdhury wrote:
>
>
> On 3/21/2023 11:07 PM, Krzysztof Kozlowski wrote:
>> On 21/03/2023 14:51, 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 regre
>>
>>
>>> +/**
>>> + * struct boot_stats - timestamp information related to boot stats
>>> + * @bootloader_start: Time for the starting point of the abl bootloader
>>> + * @bootloader_end: Time when the kernel starts loading from abl bootloader
>>> + */
>>> +struct boot_stats {
>>> + u32 bootloader_start;
>>> + u32 bootloader_end;
>>> +} __packed;
>>> +
>>> +static struct boot_stats __iomem *boot_stats;
>>> +static void __iomem *mpm_counter_base;
>>> +static u32 mpm_counter_freq;
>>
>> No file-scope variables. Does not scale, not easy for review and
>> maintenance. Avoid such code.
>
> Ack
>>
>>> +
>>> +static int mpm_parse_dt(void)
>>> +{
>>> + struct device_node *np_imem, *np_mpm2;
>>> +
>>> + np_imem = of_find_compatible_node(NULL, NULL,
>>> + "qcom,imem-boot_stats");
>>> + if (!np_imem) {
>>> + pr_err("can't find qcom,imem node\n");
>>
>> So you are printing errors everywhere, on every soc and with compile
>> test on every platform there is in the world... sorry, it does not work
>> like that.
>
> Ack
>>
>>> + return -ENODEV;
>>> + }
>>> + boot_stats = of_iomap(np_imem, 0);
>>> + if (!boot_stats) {
>>> + pr_err("boot_stats: Can't map imem\n");
>>> + goto err1;
>>> + }
>>
>>
>>> +
>>> +static void __exit boot_stats_exit(void)
>>> +{
>>> +}
>>> +module_exit(boot_stats_exit)
>>
>>
>> I don't think this is some special code which deserves init calls. Make
>> it module_platform_driver().
>
> Since this just reads some values from the Imem region and prints it to
> the user and doesn't have a specific device associated with it, a
Which is not really an argument for such antipattern, but okay...
> generic module code is written for it and not a module_platform_driver().
... so how do you handle deferred probe?
Best regards,
Krzysztof
