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 55DE4C4167B for ; Fri, 10 Nov 2023 17:43:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345906AbjKJRnL (ORCPT ); Fri, 10 Nov 2023 12:43:11 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46608 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235231AbjKJRl6 (ORCPT ); Fri, 10 Nov 2023 12:41:58 -0500 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id D77133878E for ; Fri, 10 Nov 2023 06:03:51 -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 2379112FC; Fri, 10 Nov 2023 06:04:36 -0800 (PST) Received: from [10.57.36.221] (unknown [10.57.36.221]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 22FEA3F7C5; Fri, 10 Nov 2023 06:03:48 -0800 (PST) Message-ID: Date: Fri, 10 Nov 2023 14:03:47 +0000 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v3 1/6] drm/panfrost: Perform hard reset to recover GPU if soft reset fails To: AngeloGioacchino Del Regno , boris.brezillon@collabora.com Cc: 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, wenst@chromium.org, kernel@collabora.com References: <20231109102543.42971-1-angelogioacchino.delregno@collabora.com> <20231109102543.42971-2-angelogioacchino.delregno@collabora.com> Content-Language: en-GB From: Steven Price In-Reply-To: <20231109102543.42971-2-angelogioacchino.delregno@collabora.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 09/11/2023 10:25, AngeloGioacchino Del Regno wrote: > Even though soft reset should ideally never fail, during development of > some power management features I managed to get some bits wrong: this > resulted in GPU soft reset failures, where the GPU was never able to > recover, not even after suspend/resume cycles, meaning that the only > way to get functionality back was to reboot the machine. > > Perform a hard reset after a soft reset failure to be able to recover > the GPU during runtime (so, without any machine reboot). > > Signed-off-by: AngeloGioacchino Del Regno Reviewed-by: Steven Price > --- > drivers/gpu/drm/panfrost/panfrost_gpu.c | 13 ++++++++++--- > drivers/gpu/drm/panfrost/panfrost_regs.h | 1 + > 2 files changed, 11 insertions(+), 3 deletions(-) > > diff --git a/drivers/gpu/drm/panfrost/panfrost_gpu.c b/drivers/gpu/drm/panfrost/panfrost_gpu.c > index f0be7e19b13e..ae3f7d97bb47 100644 > --- a/drivers/gpu/drm/panfrost/panfrost_gpu.c > +++ b/drivers/gpu/drm/panfrost/panfrost_gpu.c > @@ -60,14 +60,21 @@ int panfrost_gpu_soft_reset(struct panfrost_device *pfdev) > > gpu_write(pfdev, GPU_INT_MASK, 0); > gpu_write(pfdev, GPU_INT_CLEAR, GPU_IRQ_RESET_COMPLETED); > - gpu_write(pfdev, GPU_CMD, GPU_CMD_SOFT_RESET); > > + gpu_write(pfdev, GPU_CMD, GPU_CMD_SOFT_RESET); > ret = readl_relaxed_poll_timeout(pfdev->iomem + GPU_INT_RAWSTAT, > val, val & GPU_IRQ_RESET_COMPLETED, 100, 10000); > > if (ret) { > - dev_err(pfdev->dev, "gpu soft reset timed out\n"); > - return ret; > + dev_err(pfdev->dev, "gpu soft reset timed out, attempting hard reset\n"); > + > + gpu_write(pfdev, GPU_CMD, GPU_CMD_HARD_RESET); > + ret = readl_relaxed_poll_timeout(pfdev->iomem + GPU_INT_RAWSTAT, val, > + val & GPU_IRQ_RESET_COMPLETED, 100, 10000); > + if (ret) { > + dev_err(pfdev->dev, "gpu hard reset timed out\n"); > + return ret; > + } > } > > gpu_write(pfdev, GPU_INT_CLEAR, GPU_IRQ_MASK_ALL); > diff --git a/drivers/gpu/drm/panfrost/panfrost_regs.h b/drivers/gpu/drm/panfrost/panfrost_regs.h > index 55ec807550b3..c25743b05c55 100644 > --- a/drivers/gpu/drm/panfrost/panfrost_regs.h > +++ b/drivers/gpu/drm/panfrost/panfrost_regs.h > @@ -44,6 +44,7 @@ > GPU_IRQ_MULTIPLE_FAULT) > #define GPU_CMD 0x30 > #define GPU_CMD_SOFT_RESET 0x01 > +#define GPU_CMD_HARD_RESET 0x02 > #define GPU_CMD_PERFCNT_CLEAR 0x03 > #define GPU_CMD_PERFCNT_SAMPLE 0x04 > #define GPU_CMD_CYCLE_COUNT_START 0x05