From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from sender6-op-o11.zoho.com (sender6-op-o11.zoho.com [165.173.180.11]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 32B37387341 for ; Wed, 14 Oct 2026 18:06:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=pass smtp.client-ip=165.173.180.11 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792001168; cv=pass; b=q6cPrLvIbyo3t2Q/eLysoynN1MTjJEKMrynMDl5/GiRC3FKn4C4AeTHvBdY7CPFWT99tIC1/eDqQYAzoTLEBT6pekVxlWbdrqKTxxdghX7+5kesBkK0lRovlvb45rDaat5buVAjftNjib/plWrBzu3bnoAj8mae7p/qtqLHJdyk= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792001168; c=relaxed/simple; bh=oW+nFZqJCysGp2rFfmkjy6xQ4hJcmsjzsI4DvMsx5Xo=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=nZrWmInIsvUffTu2rdnJ9vcf41LVVGNvhXglWeOLKphN3kKxBlM5U9KQLpuDpHZOXX7usmjJAKhGdE1LYmlhyTEMxlnemaXSIJqDLIGGhxFBLwNyvkJP5z9ntx5fLJZfwsFh4jHs6AplTfndG9v4h7mHWpcVciJQQVDPNOXdmVQ= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=collabora.com; spf=pass smtp.mailfrom=collabora.com; dkim=pass (1024-bit key) header.d=collabora.com header.i=adrian.larumbe@collabora.com header.b=K8EQHOYY; arc=pass smtp.client-ip=165.173.180.11 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=collabora.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=collabora.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=collabora.com header.i=adrian.larumbe@collabora.com header.b="K8EQHOYY" ARC-Seal: i=1; a=rsa-sha256; t=1792001148; cv=none; d=zohomail.com; s=zohoarc; b=NsbQnA61ZTaqYF+Ge0WNhwJd5YjHvf9TYlu1ewi6OD1Cndwus87hYBGwTtQHEQJRhsIGVoE8mYzhEamYYZ8F9Ae7c+AH9BdqLIqbcldkvSQZcHjBFVhfiUDoFJmae+4YAPqnaig+lBtq8INM/5DjQi/1xebQl7maeJD4R8JP4HI= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1792001148; h=Content-Type:Content-Transfer-Encoding:Cc:Cc:Date:Date:From:From:In-Reply-To:MIME-Version:Message-ID:Subject:Subject:To:To:Message-Id:Reply-To; bh=dRfIeGV/wzE5R3Fwbev1l1gvsAUF7ieD+3RdpMlIcgg=; b=nv2bl2nv58kTurIei8POC43BW45ZGp/na0+le5Kn8V6g2t8CBFYfPisxX48Rq5Pg8lHKpPNyFC07E/yVh3VQSFtR2jXjAlsZT1h585NNe5AeeLYRknBw9QW3FAzNREcpf41qTSpDSC7NjA7D4QEHfJAiFVi033JzRkSCkPcMcqY= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass header.i=collabora.com; spf=pass smtp.mailfrom=adrian.larumbe@collabora.com; dmarc=pass header.from= DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; t=1792001148; s=zohomail; d=collabora.com; i=adrian.larumbe@collabora.com; h=Date:Date:From:From:To:To:Cc:Cc:Subject:Subject:Message-ID:MIME-Version:Content-Type:Content-Transfer-Encoding:In-Reply-To:Message-Id:Reply-To; bh=dRfIeGV/wzE5R3Fwbev1l1gvsAUF7ieD+3RdpMlIcgg=; b=K8EQHOYYr2a/EMtti8/EF1DJZu6Ysl30J0wM6vZ12OqpA0h5110EH2XDyL0dHAtF TwP7KKGrFiC96fSBh/+XpNTIYY6kJshfQb0N2DdEw8b0ULH9EEfxFnTqMdM0VFHDrw4 2p6VUsEIXdNsSojbNNon6HA+4cH/KjC87WUEHdko= Received: by smtp.zohomail.com with SMTPS id 1792001147041308.53039111812893; Wed, 14 Oct 2026 11:05:47 -0700 (PDT) Date: Wed, 14 Oct 2026 19:05:42 +0100 From: =?utf-8?Q?Adri=C3=A1n?= Larumbe To: Christian Hewitt Cc: Boris Brezillon , Rob Herring , Steven Price , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , Neil Armstrong , AngeloGioacchino Del Regno , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] drm/panfrost: reset the Amlogic GXM GPU on runtime resume Message-ID: References: <20260930125629.2691968-1-christianshewitt@gmail.com> <179184031154.1056803.12154076398577087527.b4-review@b4> <6B9C57A7-8BE5-461B-B44B-EF91FC2D2D93@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-Zoho-Virus-Status: 1 X-Zoho-AV-Stamp: zmail-av-0.2.13.1.5.4/291.982.13 CC: Neil Armstrong On 14.10.2026 19:03, Adrián Larumbe wrote: > Hi Christian, > > On 13.10.2026 09:02, Christian Hewitt wrote: > > > On 13 Oct 2026, at 1:25 am, Adrián Larumbe wrote: > > > > > > On Wed, 30 Sep 2026 12:56:29 +0000, Christian Hewitt wrote: > > >> After its first runtime suspend, every power-off of the Mali-T820 in > > >> Amlogic GXM SoCs times out and floods the log with shader, tiler and L2 > > >> power transition timeouts. Following a soft reset the cores report not > > >> ready but PWRTRANS never clears, however long the driver waits. > > > > > > Would you mind building the driver from the latest drm-misc-next and testing > > > whether this is still the case? Today I merged a patch series with a fix > > > for a long-standing bug that prevented the device from going into suspension > > > because of mismanagement of the PM refcount. It might be that what you report > > > as an issue triggered by power transitions is something altogether different. > > > > I’d tested with the v12 iteration of your series in my amlogic-7.3.y [0] tree > > before generating the patch I submitted. I’ve now tested with v15 (as merged) > > and other recent panfrost patches you submitted (which v15 depends upon) and > > with this patch reverted, and the timeout issue with T820 remains. I also saw > > a splat that I wasn’t seeing with the v12 iteration [1]. > > > > [0] https://github.com/chewitt/linux/commits/amlogic-7.3.y > > [1] https://paste.libreelec.tv/desertic-cataleya.log > > Turns out I was wrong about having easy access to a Khadas VIM2, so whatever I try to > gather about the existing bug must come from these logs. I see one very interesting > warning in [1]: > > WARNING: drivers/gpu/drm/panfrost/panfrost_device.c:490 at panfrost_exception_name+0x1c/0x30 [panfrost], CPU#0: swapper/0/0 > > Something's causing the GPU to report a fault whose status code is at > present not documented in the driver. > > I think that, because this seems like an SoC integration issue, and because of the unknown > exception being reported by the GPU, we should have some further input from an Amlogic SoC > subsystem maintainer, and also Steven Price himself. > > > After reinstating this patch on v15 + dependencies dmesg is clean again [2]. > > > > [2] https://paste.libreelec.tv/leptosomatic-cherlyn.log > > > > >> The transitions complete normally when the GPU comes out of a hardware > > >> reset, as it does at probe. Use runtime PM with reset and clock control > > > > > > panfrost_device_reset() is always called as part of the PM runtime resume > > > operation, so I'm assuming what you mean here is that reset control is > > > deasserted at runtime resume when the SoC supports it > > > > I’m firmly at the hobbyist end of kernel contributors and I’m not able to > > technically explain the patch Claude created. It’s entirely possible that it > > pokes around in the right area of code but is not the correct fix, but I lack > > the knowledge to dig further without explicit guidance. I can also give you > > remote access to a Khadas VIM2 board if that would be easier or useful? > > > > Christian > > Adrian Larumbe