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Message-ID: <e53cec31-9452-4c2a-a3a1-b6ef33be8e22@arm.com>
Date:   Mon, 4 Dec 2023 17:20:49 +0530
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Subject: Re: [PATCH V2 6/7] coresight: stm: Move ACPI support from AMBA driver
 to platform driver
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To:     James Clark <james.clark@arm.com>,
        linux-arm-kernel@lists.infradead.org, suzuki.poulose@arm.com
Cc:     Lorenzo Pieralisi <lpieralisi@kernel.org>,
        Sudeep Holla <sudeep.holla@arm.com>,
        Mike Leach <mike.leach@linaro.org>,
        Maxime Coquelin <mcoquelin.stm32@gmail.com>,
        Alexandre Torgue <alexandre.torgue@foss.st.com>,
        linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org,
        coresight@lists.linaro.org,
        linux-stm32@st-md-mailman.stormreply.com
References: <20231201062053.1268492-1-anshuman.khandual@arm.com>
 <20231201062053.1268492-7-anshuman.khandual@arm.com>
 <0adc3a16-0fc4-2a25-cd48-4667881b9490@arm.com>
From:   Anshuman Khandual <anshuman.khandual@arm.com>
In-Reply-To: <0adc3a16-0fc4-2a25-cd48-4667881b9490@arm.com>
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On 12/4/23 15:53, James Clark wrote:
> 
> 
> On 01/12/2023 06:20, Anshuman Khandual wrote:
>> Add support for the stm devices in the platform driver, which can then be
>> used on ACPI based platforms. This change would now allow runtime power
>> management for ACPI based systems. The driver would try to enable the APB
>> clock if available.
>>
>> Cc: Lorenzo Pieralisi <lpieralisi@kernel.org>
>> Cc: Sudeep Holla <sudeep.holla@arm.com>
>> Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
>> Cc: Mike Leach <mike.leach@linaro.org>
>> Cc: James Clark <james.clark@arm.com>
>> Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com>
>> Cc: Alexandre Torgue <alexandre.torgue@foss.st.com>
>> Cc: linux-acpi@vger.kernel.org
>> Cc: linux-arm-kernel@lists.infradead.org
>> Cc: linux-kernel@vger.kernel.org
>> Cc: coresight@lists.linaro.org
>> Cc: linux-stm32@st-md-mailman.stormreply.com
>> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
>> ---
> [...]
>>  
>> -module_amba_driver(stm_driver);
>> +static int stm_platform_probe(struct platform_device *pdev)
>> +{
>> +	struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> +	int ret = 0;
>> +
>> +	pm_runtime_get_noresume(&pdev->dev);
>> +	pm_runtime_set_active(&pdev->dev);
>> +	pm_runtime_enable(&pdev->dev);
>> +
>> +	ret = __stm_probe(&pdev->dev, res, NULL);
> 
> Very minor nit, but this used to print this:
> 
>   coresight stm0: STM500 initialized
> 
> And now it prints this:
> 
>   coresight stm0: (null) initialized
> 
> (null) kind of makes it look a little bit like something has gone wrong.
> Maybe we could just put "initialised" if you don't have a string from ACPI?

__stm_probe() gets called from both AMBA and platform driver paths. Even though
a NULL check inside dev_info(..."%s initialized\n",...) could be added, but how
to differentiate it from a scenario when coresight_get_uci_data() returns NULL ?