From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 50B51145B10; Fri, 5 Jul 2024 17:16:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720199779; cv=none; b=KU2zhnBUxiveTN7G3Yh2VNR7yODscZmUseGWj0dHnD9JHyCvtCHOyEr87lqlGkzaR6xloEpxGxDdpNQL1/QhJdU8CD1HPgeKMSuAkdoP29PtmIvt9ew4NcXqLJhjeRBlgWNBQS5Jn4uem49wHxZ46v/sXsiWC/WN0PbvwQLUs00= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720199779; c=relaxed/simple; bh=dyBujqfWYpPCAs4mHLwy33nhm7q7ECkO9yM4OZ211+M=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=gbI6+Y3dqbWSg4h5VAfp7rzibPxKOQT9iNVImV0ws43g4tZPvi5pxzrD7dgZzLcUBcvzGj1deCQkNbDby+1Sd3RTm7RtqxcmqJHZUpbU0AaNg5rSW19qiI/shuC6DYJkTRuDgjHkd/vb+qhEcJu/qnx/hXz8b3/W1SjW7vG4Mto= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com 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 6356BDA7; Fri, 5 Jul 2024 10:16:41 -0700 (PDT) Received: from [172.27.42.201] (usa-sjc-mx-foss1.foss.arm.com [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 040D93F762; Fri, 5 Jul 2024 10:16:16 -0700 (PDT) Message-ID: <38e46b44-6248-45e8-bdf9-66008a2fe290@arm.com> Date: Fri, 5 Jul 2024 12:16:14 -0500 Precedence: bulk X-Mailing-List: linux-pm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 09/11] usb: dwc2: Skip clock gating on Broadcom SoCs Content-Language: en-US To: Stefan Wahren , Lukas Wunner Cc: Florian Fainelli , Minas Harutyunyan , Greg Kroah-Hartman , Ray Jui , Scott Branden , Maxime Ripard , Thomas Gleixner , Jassi Brar , Ulf Hansson , Jiri Slaby , Dave Stevenson , Maarten Lankhorst , Thomas Zimmermann , David Airlie , Daniel Vetter , Peter Robinson , dri-devel@lists.freedesktop.org, bcm-kernel-feedback-list@broadcom.com, linux-pm@vger.kernel.org, linux-serial@vger.kernel.org, linux-usb@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kernel-list@raspberrypi.com References: <20240630153652.318882-1-wahrenst@gmx.net> <20240630153652.318882-10-wahrenst@gmx.net> <95762956-b46a-4dfa-b22f-bccbfa39558d@broadcom.com> <4502d826-d80c-4a98-a889-da7badfa698e@gmx.net> <43fa421c-5e5b-40a6-a546-d80e753586e3@gmx.net> From: Jeremy Linton In-Reply-To: <43fa421c-5e5b-40a6-a546-d80e753586e3@gmx.net> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Hi, On 7/5/24 10:21, Stefan Wahren wrote: > Hi Jeremy, > > Am 05.07.24 um 17:03 schrieb Lukas Wunner: >> On Fri, Jul 05, 2024 at 12:22:33PM +0200, Stefan Wahren wrote: >>> Am 05.07.24 um 10:48 schrieb Lukas Wunner: >>>> The real question is whether BCM2848 platforms likewise cannot disable >>>> the clock of the dwc2 controller or whether this is specific to the >>>> BCM2835.  Right now dwc2_set_bcm_params() is applied to both the >>>> BCM2848 and BCM2835.  If the BCM2848 behaves differently in this >>>> regard, we'd have to duplicate dwc2_set_bcm_params() for the BCM2835. >>>  From my understand BCM2848 refers to the same SoC, but the ACPI >>> implementation uses a different ID [2]. So I think this is safe. >>> [2] - >>> https://patches.linaro.org/project/linux-usb/patch/20210413215834.3126447-2-jeremy.linton@arm.com/ >> Careful there, the patch vaguely says... >> >>      With that added and identified as "BCM2848", >>      an id in use by other OSs for this device, the dw2 >>      controller on the BCM2711 will work. >> >> ...which sounds like they copy-pasted the BCM2848 id from somewhere else. >> I would assume that BCM2848 is really a different SoC and not just >> a different name for the BCM2835, but hopefully BroadCom folks will >> be able to confirm or deny this (and thus the necessity of the quirk >> on BCM2848 and not just on BCM2835). > could you please clarify this situation? This id comes from the edk2-platforms ACPI tables and is currently used by both the rpi3 and rpi4, and AFAIK nothing else as the rpi5-dev work is currently only exposing XHCI. The ID is strictly the USB controller not the SoC. Its a bit confusingly named, but something we inherited from the much older windows/edk2 port, where it appears that the peripheral HID's were just picked in numerical order. [0] https://github.com/tianocore/edk2-platforms/blob/12f68d29abdc9d703f67bd743fdec23ebb1e966e/Platform/RaspberryPi/AcpiTables/GpuDevs.asl#L15