From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 83884C624B4 for ; Thu, 23 Nov 2023 11:58:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345192AbjKWL6V (ORCPT ); Thu, 23 Nov 2023 06:58:21 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46454 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345199AbjKWL6Q (ORCPT ); Thu, 23 Nov 2023 06:58:16 -0500 Received: from madras.collabora.co.uk (madras.collabora.co.uk [46.235.227.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6D83ED6E for ; Thu, 23 Nov 2023 03:58:22 -0800 (PST) Received: from [100.107.97.3] (cola.collaboradmins.com [195.201.22.229]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: kholk11) by madras.collabora.co.uk (Postfix) with ESMTPSA id 77D6C660739C; Thu, 23 Nov 2023 11:58:20 +0000 (GMT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1700740701; bh=NUR7NWmLJG7x3qkoi7nPz/LMqTSzR6NXYNSINLPbFko=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=LIjrCro2/jqzussd+3G5b/ksbF+N7x0hbAl/xffwiaEBVWI4oNSOStDCEdvIwSr0N PSb8YNLyCgeYEsow8ZZ4cox4a8m7dk/pYduxd+msa7nLDyxEEVe6zSj3CmVAyP0GjO G/W1HNhEsX5aUkQD8HRB8z781UdIA+xotevHOkJ4yvW4yLUKUQxFBqxdUfTR0eZnw9 cRyOTvP5+4rHFXR0M0XxX3JMcqOtfAUZ7ki5ttq+/o1tkTn5yl8ueIRLVet5/qcA7b /71XSIATnecHQW1iLGQryC+UedZ6imRZD7BX5MUsfRH9+WFiGS/sZW2Er7LIHQH+mb GIcVRCzUwovvA== Message-ID: <3eef79bd-d271-4916-b3f0-220a5ce984ba@collabora.com> Date: Thu, 23 Nov 2023 12:58:17 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2] drm/panfrost: Ignore core_mask for poweroff and sync interrupts Content-Language: en-US To: Krzysztof Kozlowski , steven.price@arm.com Cc: boris.brezillon@collabora.com, robh@kernel.org, maarten.lankhorst@linux.intel.com, mripard@kernel.org, tzimmermann@suse.de, airlied@gmail.com, daniel@ffwll.ch, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org References: <20231123115029.68422-1-angelogioacchino.delregno@collabora.com> <2bd59614-49d8-4829-861e-3b95c44008df@linaro.org> From: AngeloGioacchino Del Regno In-Reply-To: <2bd59614-49d8-4829-861e-3b95c44008df@linaro.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Il 23/11/23 12:57, Krzysztof Kozlowski ha scritto: > On 23/11/2023 12:50, AngeloGioacchino Del Regno wrote: >> Some SoCs may be equipped with a GPU containing two core groups >> and this is exactly the case of Samsung's Exynos 5422 featuring >> an ARM Mali-T628 MP6 GPU: the support for this GPU in Panfrost >> is partial, as this driver currently supports using only one >> core group and that's reflected on all parts of it, including >> the power on (and power off, previously to this patch) function. >> >> The issue with this is that even though executing the soft reset >> operation should power off all cores unconditionally, on at least >> one platform we're seeing a crash that seems to be happening due >> to an interrupt firing which may be because we are calling power >> transition only on the first core group, leaving the second one >> unchanged, or because ISR execution was pending before entering >> the panfrost_gpu_power_off() function and executed after powering >> off the GPU cores, or all of the above. >> >> Finally, solve this by introducing a new panfrost_gpu_suspend_irq() >> helper function and changing the panfrost_device_suspend() flow to >> 1. Mask and clear all interrupts: we don't need nor want any, as >> for power_off() we are polling PWRTRANS, but we anyway don't >> want GPU IRQs to fire while it is suspended/powered off; >> 2. Call synchronize_irq() after that to make sure that any pending >> ISR is executed before powering off the GPU Shaders/Tilers/L2 >> hence avoiding unpowered registers R/W; and >> 3. Ignore the core_mask and ask the GPU to poweroff both core groups >> >> Of course it was also necessary to add a `irq` variable to `struct >> panfrost_device` as we need to get that in panfrost_gpu_power_off() >> for calling synchronize_irq() on it. >> >> Fixes: 22aa1a209018 ("drm/panfrost: Really power off GPU cores in panfrost_gpu_power_off()") >> [Regression detected on Odroid HC1, Exynos5422, Mali-T628 MP6] >> Reported-by: Krzysztof Kozlowski >> Signed-off-by: AngeloGioacchino Del Regno >> --- >> >> Changes in v2: >> - Fixed the commit hash of "Really power off [...]" >> - Actually based on a clean next-20231121 >> - Renamed "irq" to "gpu_irq" as per Boris' suggestion >> - Moved the IRQ mask/clear/sync to a helper function and added >> a call to that in panfrost_device.c instead of doing that in >> panfrost_gpu_power_off(). >> >> NOTE: I didn't split 1+2 from 3 as suggested by Boris, and I'm sending >> this one without waiting for feedback on my reasons for that which I >> explained as a reply to v1 because the former couldn't be applied to >> linux-next, and I want to unblock Krzysztof ASAP to get this tested. >> > > This does not compile. > I really have to take a break. My brain starts failing, as I can see. Sorry.