From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pg1-f228.google.com (mail-pg1-f228.google.com [209.85.215.228]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E864550AC3D for ; Thu, 3 Sep 2026 19:40:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.215.228 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788464435; cv=none; b=SgDiU8FSrJ7WkIz3+2cDXxy3a6Oq1PBTZ1ZBhbO2G5nGINLKXh0M/7glzNocOdvwQP8pW1hIPIdGwUQKlouuoJl+8rxn/uCK7aJzXDPfHtOaj9kba8sG0w1JdFdsIhK2lXONB0oPmp1I1dhzAa/4JYBLeWIRAS/6C8MMl5AkfJg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788464435; c=relaxed/simple; bh=59JAhlyzGm7Y0kjtf+cA64P3VtNlNyMr2+Ukst/oW4A=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=rdcXtYooYy3KIRYgDxtidBlRNTDOGqhoB2LvmU3DeW1I5iRMH1ERUJG1S9mkNhIKjJClhlmtlOvKXWhqWbUYW7TOOi42np2kQsMCNk6g2CsZhvfanPyX89nIP+Me8YxRHy6Mr26iXD1ptPj2cMGLaQUGHTZhI24W+szYHTvMkTI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=broadcom.com; spf=fail smtp.mailfrom=broadcom.com; dkim=pass (1024-bit key) header.d=broadcom.com header.i=@broadcom.com header.b=QRLbqf+B; arc=none smtp.client-ip=209.85.215.228 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=broadcom.com Authentication-Results: smtp.subspace.kernel.org; spf=fail smtp.mailfrom=broadcom.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=broadcom.com header.i=@broadcom.com header.b="QRLbqf+B" Received: by mail-pg1-f228.google.com with SMTP id 41be03b00d2f7-cc1c7364550so406093a12.1 for ; Thu, 03 Sep 2026 12:40:22 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1788464417; x=1789069217; h=content-transfer-encoding:content-type:in-reply-to:autocrypt:from :content-language:references:cc:to:subject:user-agent:mime-version :date:message-id:dkim-signature:x-gm-gg:x-gm-message-state:from:to :cc:subject:date:message-id:reply-to:content-type; bh=p8+z4kiOtdTmn8miWX+XqbRCAv1t3K0Ial/sw+P7zoA=; b=lNZXxzARlibTcuzAwL8R/Ckn3T/jnbwbMv+ZLgfynTCmDZWhiO61/9F3WQf2NuqmAy MPQEisFHgOgPpwpq5CopQY4DUhbF0u5gUR1aHGVD6Hc8tgxPxf5YoMZa3fRmzofpn0Fx 9nGgMDuNzEejiJoaTGaR7GjKsmFaW3VcJdKUOoUWdiQKssE15GZoWRF/M/bU3ea5qcY3 vYNBRQfBwtSFY4MXe/kvIfVvHq+/YfpDd6pWPVCGnoWxv+6qzhxmOjuFvQeoqx+LiEFR v4Qke0B09+zqUU9TLTVkj7nkEliO3N/UfOxRjyXpJjZWUGX5OlSBT7U4HFEikaIcZ6kJ nmGQ== X-Forwarded-Encrypted: i=1; AKwUvBxzsaHfCXjL2HsJ00AuAHjJOT0znmYTdfiz/fumc8zwjrL36Oz/490tLfpViu00mT/EQBocAFoBtmWI@vger.kernel.org X-Gm-Message-State: AFuF++mLaXFaUrxlr0RmCbI48oqLfNjo7ocDpq8jOlCv12YU6xUpSGw4 d8N8NojIHfiJB1Q+ACvKVFYRiBO3/KGis11fs260DQp2hskqey37dMyD+OhgYOeToSRLedTnmDc vr2aliw4QlqDz2rTzjNRDwoxmwtmqj06KPS3/qmVfhSp8/Iwoxrz815AHTQnUe8NFIiP4dHcBzq XbyOPurRjHx3As+kiFcBiPZu46ileN/9LB9/w4VyZf5dh82sEI6IVB6Gi473mZkoibwS38ZbPl3 tsdvcgKuUUUlz6vDHzNYQ== X-Gm-Gg: AYBFou1WtaFAOJjUBQjrSv/Egdkgzf06iZot25ub9Yw8aDWvyM5X5RvlGjlhuwPjyPN ZNfAAk65YLLOGHaCuRE1p2XjG3G4ZCAXpoi4PZKA7V7UcyqoY98MgPFGXen+GXSixJxAv3UNhbf gjQ08VYYOu47vCFacQqleIynvfrNS9PZXn0ohYr11Eo2qz+ZXhupxGCkQxEQHOmW6hVaxgN+wlb 5ffdOinI1MrM0QF36n8IQjD55eor3LA6BPQ5NwdUNv7wyMdpkRrySXKcJmynBy2a50xfz7Z2Jpr TNMQwmozUv1iJ16NOTeqZYNuL40zMYOh6zcBRQCC634r8YZTxIlDaujRcfq5mS7l7iPEckIEt28 vKeXL339ie6b8cT0xeFB3tMkv2sl4bWKSKBoJZZnhgcvPgxZVLKB5wJOGkiF8OP3pLKGoswcIG/ BeMiwoHM+33sRyq4/X+ggBEtzeYD+RJizoDmavvCLW X-Received: by 2002:a17:90b:5866:b0:398:e73e:5a13 with SMTP id 98e67ed59e1d1-39b2613272amr1297614a91.9.1788464416724; Thu, 03 Sep 2026 12:40:16 -0700 (PDT) Received: from smtp-us-east1-p01-i01-si01.dlp.protect.broadcom.com (address-144-49-247-25.dlp.protect.broadcom.com. [144.49.247.25]) by smtp-relay.gmail.com with ESMTPS id 98e67ed59e1d1-39aec45e666sm508905a91.0.2026.09.03.12.40.16 for (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Thu, 03 Sep 2026 12:40:16 -0700 (PDT) X-Relaying-Domain: broadcom.com X-CFilter-Loop: Reflected Received: by mail-pg1-f200.google.com with SMTP id 41be03b00d2f7-cc4216aee8fso379487a12.1 for ; Thu, 03 Sep 2026 12:40:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=broadcom.com; s=google; t=1788464415; x=1789069215; darn=vger.kernel.org; h=content-transfer-encoding:content-type:in-reply-to:autocrypt:from :content-language:references:cc:to:subject:user-agent:mime-version :date:message-id:from:to:cc:subject:date:message-id:reply-to :content-type; bh=p8+z4kiOtdTmn8miWX+XqbRCAv1t3K0Ial/sw+P7zoA=; b=QRLbqf+Bl11XLJHyWP1yoN9CPTjwh3uOTYJgbkAi0/8I5+HIFd8LeiharcDDOmSrZ2 yqHcg6sUMDJDcYyi70S+bG7ej00toaoiIy+affPgjO06CPeW1dhRXC9jJ9xuyBdqYUPU 3g50ioVgcVaIFGeTcc3ktojcsNh1VhhX2QBvE= X-Forwarded-Encrypted: i=1; AKwUvBwqxV4ARt5FtKg1sGZ/hhCZREiNH3VJR864lNClr9XWrn2FlNll2a3Ju2RmXWgAWNazIe1USxSKrlN/@vger.kernel.org X-Received: by 2002:a17:90a:e703:b0:398:e969:87ef with SMTP id 98e67ed59e1d1-39b2629926dmr1274557a91.24.1788464414682; Thu, 03 Sep 2026 12:40:14 -0700 (PDT) X-Received: by 2002:a17:90a:e703:b0:398:e969:87ef with SMTP id 98e67ed59e1d1-39b2629926dmr1274468a91.24.1788464414183; Thu, 03 Sep 2026 12:40:14 -0700 (PDT) Received: from [10.67.48.245] ([192.19.223.252]) by smtp.gmail.com with ESMTPSA id 5a478bee46e88-3339b6036fcsm1124198eec.20.2026.09.03.12.40.13 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 03 Sep 2026 12:40:13 -0700 (PDT) Message-ID: Date: Thu, 3 Sep 2026 12:40:12 -0700 Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 3/4] drm/vc4: Use the reset controller to recover from a GPU hang To: =?UTF-8?Q?Ma=C3=ADra_Canal?= , Maxime Ripard , Dave Stevenson , Raspberry Pi Kernel Maintenance , Stefan Wahren , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Ray Jui , Scott Branden , Broadcom internal kernel review list Cc: kernel-dev@igalia.com, dri-devel@lists.freedesktop.org, devicetree@vger.kernel.org, linux-rpi-kernel@lists.infradead.org, linux-arm-kernel@lists.infradead.org References: <20260816-vc4-reset-control-v1-0-896444373716@igalia.com> <20260816-vc4-reset-control-v1-3-896444373716@igalia.com> Content-Language: en-US, fr-FR From: Florian Fainelli Autocrypt: addr=florian.fainelli@broadcom.com; keydata= xsBNBFPAG8ABCAC3EO02urEwipgbUNJ1r6oI2Vr/+uE389lSEShN2PmL3MVnzhViSAtrYxeT M0Txqn1tOWoIc4QUl6Ggqf5KP6FoRkCrgMMTnUAINsINYXK+3OLe7HjP10h2jDRX4Ajs4Ghs JrZOBru6rH0YrgAhr6O5gG7NE1jhly+EsOa2MpwOiXO4DE/YKZGuVe6Bh87WqmILs9KvnNrQ PcycQnYKTVpqE95d4M824M5cuRB6D1GrYovCsjA9uxo22kPdOoQRAu5gBBn3AdtALFyQj9DQ KQuc39/i/Kt6XLZ/RsBc6qLs+p+JnEuPJngTSfWvzGjpx0nkwCMi4yBb+xk7Hki4kEslABEB AAHNMEZsb3JpYW4gRmFpbmVsbGkgPGZsb3JpYW4uZmFpbmVsbGlAYnJvYWRjb20uY29tPsLB IQQQAQgAywUCZWl41AUJI+Jo+hcKAAG/SMv+fS3xUQWa0NryPuoRGjsA3SAUAAAAAAAWAAFr ZXktdXNhZ2UtbWFza0BwZ3AuY29tjDAUgAAAAAAgAAdwcmVmZXJyZWQtZW1haWwtZW5jb2Rp bmdAcGdwLmNvbXBncG1pbWUICwkIBwMCAQoFF4AAAAAZGGxkYXA6Ly9rZXlzLmJyb2FkY29t Lm5ldAUbAwAAAAMWAgEFHgEAAAAEFQgJChYhBNXZKpfnkVze1+R8aIExtcQpvGagAAoJEIEx tcQpvGagWPEH/2l0DNr9QkTwJUxOoP9wgHfmVhqc0ZlDsBFv91I3BbhGKI5UATbipKNqG13Z TsBrJHcrnCqnTRS+8n9/myOF0ng2A4YT0EJnayzHugXm+hrkO5O9UEPJ8a+0553VqyoFhHqA zjxj8fUu1px5cbb4R9G4UAySqyeLLeqnYLCKb4+GklGSBGsLMYvLmIDNYlkhMdnnzsSUAS61 WJYW6jjnzMwuKJ0ZHv7xZvSHyhIsFRiYiEs44kiYjbUUMcXor/uLEuTIazGrE3MahuGdjpT2 IOjoMiTsbMc0yfhHp6G/2E769oDXMVxCCbMVpA+LUtVIQEA+8Zr6mX0Yk4nDS7OiBlvOwE0E U8AbwQEIAKxr71oqe+0+MYCc7WafWEcpQHFUwvYLcdBoOnmJPxDwDRpvU5LhqSPvk/yJdh9k 4xUDQu3rm1qIW2I9Puk5n/Jz/lZsqGw8T13DKyu8eMcvaA/irm9lX9El27DPHy/0qsxmxVmU pu9y9S+BmaMb2CM9IuyxMWEl9ruWFS2jAWh/R8CrdnL6+zLk60R7XGzmSJqF09vYNlJ6Bdbs MWDXkYWWP5Ub1ZJGNJQ4qT7g8IN0qXxzLQsmz6tbgLMEHYBGx80bBF8AkdThd6SLhreCN7Uh IR/5NXGqotAZao2xlDpJLuOMQtoH9WVNuuxQQZHVd8if+yp6yRJ5DAmIUt5CCPcAEQEAAcLB gQQYAQIBKwUCU8AbwgUbDAAAAMBdIAQZAQgABgUCU8AbwQAKCRCTYAaomC8PVQ0VCACWk3n+ obFABEp5Rg6Qvspi9kWXcwCcfZV41OIYWhXMoc57ssjCand5noZi8bKg0bxw4qsg+9cNgZ3P N/DFWcNKcAT3Z2/4fTnJqdJS//YcEhlr8uGs+ZWFcqAPbteFCM4dGDRruo69IrHfyyQGx16s CcFlrN8vD066RKevFepb/ml7eYEdN5SRALyEdQMKeCSf3mectdoECEqdF/MWpfWIYQ1hEfdm C2Kztm+h3Nkt9ZQLqc3wsPJZmbD9T0c9Rphfypgw/SfTf2/CHoYVkKqwUIzI59itl5Lze+R5 wDByhWHx2Ud2R7SudmT9XK1e0x7W7a5z11Q6vrzuED5nQvkhAAoJEIExtcQpvGagugcIAJd5 EYe6KM6Y6RvI6TvHp+QgbU5dxvjqSiSvam0Ms3QrLidCtantcGT2Wz/2PlbZqkoJxMQc40rb fXa4xQSvJYj0GWpadrDJUvUu3LEsunDCxdWrmbmwGRKqZraV2oG7YEddmDqOe0Xm/NxeSobc MIlnaE6V0U8f5zNHB7Y46yJjjYT/Ds1TJo3pvwevDWPvv6rdBeV07D9s43frUS6xYd1uFxHC 7dZYWJjZmyUf5evr1W1gCgwLXG0PEi9n3qmz1lelQ8lSocmvxBKtMbX/OKhAfuP/iIwnTsww 95A2SaPiQZA51NywV8OFgsN0ITl2PlZ4Tp9hHERDe6nQCsNI/Us= In-Reply-To: <20260816-vc4-reset-control-v1-3-896444373716@igalia.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-DetectorID-Processed: b00c1d49-9d2e-4205-b15f-d015386d3d5e On 8/16/26 07:05, Maíra Canal wrote: > vc4_reset() recovers a hung GPU by dropping the runtime PM usage count to > zero so that the power domain goes down, and then taking it again. Such an > unconventional approach only works if the driver knows exactly how many > references it holds, which is why vc4 wrapped every pm_runtime_get_sync() > call in a private refcount and mutex. > > Commit 670c672608a1 ("soc: bcm: bcm2835-pm: Add support for power domains > under a new binding.") exposed a V3D reset line for exactly this reason, > so that the block can be reset without power-cycling its domain, but the > vc4 driver never picked it up. Use it now, which removes the need for the > private refcount and leaves vc4_v3d_pm_get/put() as plain runtime PM > wrappers. > > The reset line is optional, to accommodate older device trees. Device > trees that do not describe one still get the driver-side recovery in > vc4_irq_reset(), but the hardware is left untouched. Two in-tree platforms > use the VC4 V3D block: BCM2835 gains the resets property in the next > commit, and Cygnus is no worse off than it was, as its V3D node has no > power domain and the power-cycle only ever gated its clock. > > Signed-off-by: Maíra Canal Reviewed-by: Florian Fainelli -- Florian