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Message-ID: <92d6a66d-3270-3378-2ab9-9214c004d5c7@arm.com>
Date:   Wed, 15 Nov 2023 13:53:59 +0000
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Subject: Re: [PATCH 4/7] coresight: tpiu: Move ACPI support from AMBA driver
 to platform driver
Content-Language: en-US
To:     Anshuman Khandual <anshuman.khandual@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: <20231027072943.3418997-1-anshuman.khandual@arm.com>
 <20231027072943.3418997-5-anshuman.khandual@arm.com>
From:   James Clark <james.clark@arm.com>
In-Reply-To: <20231027072943.3418997-5-anshuman.khandual@arm.com>
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On 27/10/2023 08:29, Anshuman Khandual wrote:
> Add support for the tpiu device 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.
> 
[...]
> +#ifdef CONFIG_ACPI
> +static const struct acpi_device_id tpiu_acpi_ids[] = {
> +	{"ARMHC979", 0}, /* ARM CoreSight TPIU */
> +	{}
> +};
> +MODULE_DEVICE_TABLE(acpi, tpiu_acpi_ids);
> +#endif
> +
> +static struct platform_driver tpiu_platform_driver = {
> +	.probe	= tpiu_platform_probe,
> +	.remove	= tpiu_platform_remove,
> +	.driver = {
> +		.name			= "coresight-tpiu-platform",
> +		.acpi_match_table	= ACPI_PTR(tpiu_acpi_ids),
> +		.suppress_bind_attrs	= true,
> +		.pm			= &tpiu_dev_pm_ops,
> +	},
> +};
> +module_platform_driver(tpiu_platform_driver);
> +

Is there a special build config where this works? I get an error here
because module_platform_driver() redefines things that are in
module_amba_driver() which is defined above:

  module_amba_driver(tpiu_driver);

This isn't a W=1 build or anything, just a normal one. And it applies to
most of the patches in this set.