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[144.49.247.25]) by smtp-relay.gmail.com with ESMTPS id 98e67ed59e1d1-39b160990basm1441039a91.8.2026.09.03.12.40.16 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-f197.google.com with SMTP id 41be03b00d2f7-c89704da8c7so357440a12.0 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=lists.freedesktop.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=c9WU/usvdM0SSkvpMbGFIkhMHUWOYjekqt5QFrOXMRJu7+m1LfLA8xwf+T5kXLKjdd AfSoAEKE3BzkIkLerNRQDUHezCAwnZePc44jae3jZfZeTJ7e/qoyv1s8dwhbKufYkU3r JjCefwmIaUyBhOn4gucQOVesZaT3HbYiqvZKA= X-Forwarded-Encrypted: i=1; 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charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-DetectorID-Processed: b00c1d49-9d2e-4205-b15f-d015386d3d5e X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" 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