From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; dkim=none Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id B2D97110; Tue, 21 Nov 2023 23:02:40 -0800 (PST) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 34E521595; Tue, 21 Nov 2023 23:03:27 -0800 (PST) Received: from [10.162.41.8] (a077893.blr.arm.com [10.162.41.8]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id E6C223F73F; Tue, 21 Nov 2023 23:02:36 -0800 (PST) Message-ID: <268e1605-fe3f-4aa0-92e3-36ddfc8aacb3@arm.com> Date: Wed, 22 Nov 2023 12:32:33 +0530 Precedence: bulk X-Mailing-List: linux-acpi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 4/7] coresight: tpiu: Move ACPI support from AMBA driver to platform driver Content-Language: en-US To: James Clark , linux-arm-kernel@lists.infradead.org, suzuki.poulose@arm.com Cc: Lorenzo Pieralisi , Sudeep Holla , Mike Leach , Maxime Coquelin , Alexandre Torgue , 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> <92d6a66d-3270-3378-2ab9-9214c004d5c7@arm.com> From: Anshuman Khandual In-Reply-To: <92d6a66d-3270-3378-2ab9-9214c004d5c7@arm.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 11/15/23 19:23, James Clark wrote: > > > 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 I have been testing this with a config known to work on RB5 board. > 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. You are right, I am able to recreate this problem with defconfig on 6.7-rc2 as well. The problem here seems to be caused by having both module_amba_driver() and module_platform_driver() in the same file. #define module_amba_driver(__amba_drv) \ module_driver(__amba_drv, amba_driver_register, amba_driver_unregister) #define module_platform_driver(__platform_driver) \ module_driver(__platform_driver, platform_driver_register, \ platform_driver_unregister) Although, AFAICT, have not seen these before - even on the defconfig. Just to work around this problem, there can be a common module_init() /module_exit() to register/unregister both AMBA and platform drivers, similar to etm4x_init()/etm4x_exit() setup in coresight-etm4x-core.c.