From: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
To: Souradeep Chowdhury <quic_schowdhu@quicinc.com>,
Andy Gross <agross@kernel.org>,
Konrad Dybcio <konrad.dybcio@somainline.org>,
Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
Bjorn Andersson <andersson@kernel.org>,
Rob Herring <robh+dt@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org,
devicetree@vger.kernel.org, Sibi Sankar <quic_sibis@quicinc.com>,
Rajendra Nayak <quic_rjendra@quicinc.com>
Subject: Re: [PATCH V1 3/4] soc: qcom: boot_stat: Add Driver Support for Boot Stats
Date: Wed, 22 Mar 2023 15:53:21 +0100 [thread overview]
Message-ID: <7b939818-993a-e849-e7e0-ae9ea74ea52b@linaro.org> (raw)
In-Reply-To: <321005fc-1bfd-c04d-b2b5-d85d213ac00a@quicinc.com>
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
next prev parent reply other threads:[~2023-03-22 14:54 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-03-21 13:51 [PATCH V1 0/4] soc: qcom: boot_stats: Add driver support for boot_stats Souradeep Chowdhury
2023-03-21 13:51 ` [PATCH V1 1/4] dt-bindings: sram: qcom,imem: Add Boot Stat region within IMEM Souradeep Chowdhury
2023-03-21 17:31 ` Krzysztof Kozlowski
2023-03-22 13:34 ` Souradeep Chowdhury
2023-03-22 16:27 ` Krzysztof Kozlowski
2023-03-23 13:46 ` Souradeep Chowdhury
2023-03-21 13:51 ` [PATCH V1 2/4] dt-bindings: soc: qcom,mpm-sleep-counter: Add the dtschema Souradeep Chowdhury
2023-03-21 17:33 ` Krzysztof Kozlowski
2023-03-22 13:46 ` Souradeep Chowdhury
2023-03-22 16:29 ` Krzysztof Kozlowski
2023-03-23 13:49 ` Souradeep Chowdhury
2023-03-21 17:39 ` Krzysztof Kozlowski
2023-03-22 14:02 ` Souradeep Chowdhury
2023-03-22 16:31 ` Krzysztof Kozlowski
2023-03-23 13:51 ` Souradeep Chowdhury
2023-03-21 13:51 ` [PATCH V1 3/4] soc: qcom: boot_stat: Add Driver Support for Boot Stats Souradeep Chowdhury
2023-03-21 17:37 ` Krzysztof Kozlowski
2023-03-22 13:54 ` Souradeep Chowdhury
2023-03-22 14:53 ` Krzysztof Kozlowski [this message]
2023-03-23 13:45 ` Souradeep Chowdhury
2023-03-24 8:56 ` Krzysztof Kozlowski
2023-03-21 13:51 ` [PATCH V1 4/4] MAINTAINERS: Add the entry for boot_stats driver support Souradeep Chowdhury
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