From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from pdx-out-012.esa.us-west-2.outbound.mail-perimeter.amazon.com (pdx-out-012.esa.us-west-2.outbound.mail-perimeter.amazon.com [35.162.73.231]) (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 6B0702E401; Mon, 5 Oct 2026 11:25:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=35.162.73.231 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791199515; cv=none; b=mnubU0rZDS3SjjkicyEfWUfIUh83gou/Q5tsEMJflMPrnpb21AGH6n2FRrvhhfpvpJXgUQ27i2DJOP63cYhdnzqTSu5FvIGPRK/Wk16qldPsLWso4UGOGVDlJcQcOngRVPL9tw7Mc+d53AC95WQNLOi4JQcOyOQ5Jl2dB0oMcn0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791199515; c=relaxed/simple; bh=9sQanoGatrUxWQK8fe7jlY1Kur21DL+2mYZayq0WqV0=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=Mtug0+lGWWyXVle4i+xxqi5vjVUd1Ku8osJm2jmn0njx5Cs+ohmOnxiZf4zWCe7P28Dm/uXgNXpZY4/ls7MEldr5pKKciujaRnxZkqlK7jQrelaSX5QIFlhoZRDuwKtZ9mcY+OiXtEcUi+vATgq8w3lCkDoSVbYrA4pOPmge2TM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amazon.com; spf=pass smtp.mailfrom=amazon.com; dkim=pass (2048-bit key) header.d=amazon.com header.i=@amazon.com header.b=ZV9mBSPj; arc=none smtp.client-ip=35.162.73.231 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amazon.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=amazon.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=amazon.com header.i=@amazon.com header.b="ZV9mBSPj" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazoncorp2; t=1791199513; x=1822735513; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=DPQK3j3cTLHcegb4rnkZGuAOmGISkeATPG4ewIppAqA=; b=ZV9mBSPjNvbDNoWAkuzLzEr/BI9IrdobdxwN12G9H+O8qhwvhjDT+pCX bQi7KOU43aakTPX5ZqPVDJ8hWLraWHraQ22M+yytxe2GZKHsWzfBl4gnR Sc4YD7ZuLeAf2pNbLS+06dMHQ3uLTrYRlfN+ndDagk8nPzltV8S+TcwEC r/G1YW4cNPFColVRqL6jrd41o7TMcLdbaWM7SB/6aNP/F93CeUi4lsWQ4 ATlbUtfk44OD66Ec0IxyKQKgfHZdC1c50bwbTQDAVKoLBlQ/thp8MjUN9 iRzujS3YcHrRqkbxX3jXvdjGo0ApHEdF8QkgjBC5FVvlP4zWQtUalqxmz A==; X-CSE-ConnectionGUID: 5Wrq8AqjTsGwzrJRGEHcrQ== X-CSE-MsgGUID: lw8uPIHtSC+A7nnRBUmw1A== X-IronPort-AV: E=Sophos;i="6.27,141,1787011200"; d="scan'208";a="30227564" Received: from ip-10-5-9-48.us-west-2.compute.internal (HELO smtpout.naws.us-west-2.prod.farcaster.email.amazon.dev) ([10.5.9.48]) by internal-pdx-out-012.esa.us-west-2.outbound.mail-perimeter.amazon.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 Oct 2026 11:25:09 +0000 Received: from EX19MTAUWB001.ant.amazon.com [205.251.233.104:8807] by smtpin.naws.us-west-2.prod.farcaster.email.amazon.dev [10.0.37.83:2525] with esmtp (Farcaster) id 4f7fc473-dfb3-4f79-b495-2dd45f577288; Mon, 5 Oct 2026 11:25:09 +0000 (UTC) X-Farcaster-Flow-ID: 4f7fc473-dfb3-4f79-b495-2dd45f577288 Received: from EX19D001UWA001.ant.amazon.com (10.13.138.214) by EX19MTAUWB001.ant.amazon.com (10.250.64.248) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA) id 15.2.2562.49; Mon, 5 Oct 2026 11:25:09 +0000 Received: from dev-dsk-farbere-1a-46ecabed.eu-west-1.amazon.com (172.19.116.181) by EX19D001UWA001.ant.amazon.com (10.13.138.214) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA) id 15.2.2562.49; Mon, 5 Oct 2026 11:25:07 +0000 From: Eliav Farber To: Thomas Gleixner , Talel Shenhar CC: Radu Rendec , Rob Herring , "Krzysztof Kozlowski" , Conor Dooley , "Eliav Farber" , , Subject: [PATCH v3 3/8] irqchip/al-fic: keep the device_node instead of a cached name string Date: Mon, 5 Oct 2026 11:24:53 +0000 Message-ID: <20261005112458.22291-4-farbere@amazon.com> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20261005112458.22291-1-farbere@amazon.com> References: <20261005112458.22291-1-farbere@amazon.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain X-ClientProxiedBy: EX19D039UWA001.ant.amazon.com (10.13.139.110) To EX19D001UWA001.ant.amazon.com (10.13.138.214) struct al_fic cached a "const char *name" that al_fic_wire_init() received as a separate argument and set from node->name. That string aliased storage inside the device_node rather than being owned by the driver, but nothing in the struct expressed that dependency - al_fic just held a bare pointer with no indication of what it pointed into or why it stayed valid. This is not fixing a lifetime bug - of_irq_init() takes a reference on the node before calling the driver's init callback and never drops it on a successful init, so the node is pinned for the life of the system either way, and node->name was never actually at risk of dangling. Keeping the device_node in the struct instead of the bare name is about making the dependency explicit rather than closing a real one: it holds the object the name is derived from, and lets each site derive the name on demand instead of carrying a pointer whose validity nothing in the struct asserts. The irqchip callback that has no device_node in scope now prints the instance with %pOF, which formats the node on demand, and the name argument threaded through al_fic_wire_init() goes away. irq_alloc_domain_generic_chips() keeps the pointer it is given, so it now uses of_node_full_name(). This changes the generic chip name from the bare node name (e.g. "interrupt-controller") to the full node name including its unit address (e.g. "interrupt-controller@fd8a8500"), which keeps instances that share a bare name distinguishable. Signed-off-by: Eliav Farber --- v3: - Use of_node_full_name() instead of reaching into node->full_name directly, as Radu Rendec suggested. - Rewrite the commit message to say plainly that this patch does not fix a lifetime bug. of_irq_init() takes a reference on the node before calling the driver's init callback and does not drop it on a successful init, so the node, and the storage node->name points into, is pinned for the life of the system either way. The value of keeping the device_node is making that dependency explicit, not closing a real one. v2: new patch. Keep the device_node in struct al_fic instead of a cached name string that aliased node storage. Introduced here so the struct holds the node before the next patch requests the parent interrupt by node->full_name, keeping every commit buildable on its own. drivers/irqchip/irq-al-fic.c | 13 +++++-------- 1 file changed, 5 insertions(+), 8 deletions(-) diff --git a/drivers/irqchip/irq-al-fic.c b/drivers/irqchip/irq-al-fic.c index 760bd08dcff4..ee06d0123b7a 100644 --- a/drivers/irqchip/irq-al-fic.c +++ b/drivers/irqchip/irq-al-fic.c @@ -36,7 +36,7 @@ enum al_fic_state { struct al_fic { void __iomem *base; struct irq_domain *domain; - const char *name; + struct device_node *node; unsigned int parent_irq; enum al_fic_state state; }; @@ -89,7 +89,7 @@ static int al_fic_irq_set_type(struct irq_data *data, unsigned int flow_type) if (fic->state == AL_FIC_UNCONFIGURED) { al_fic_set_trigger(fic, gc, new_state); } else if (fic->state != new_state) { - pr_debug("fic %s state already configured to %d\n", fic->name, fic->state); + pr_debug("fic %pOF state already configured to %d\n", fic->node, fic->state); return -EINVAL; } return 0; @@ -142,7 +142,7 @@ static int al_fic_register(struct device_node *node, ret = irq_alloc_domain_generic_chips(fic->domain, NR_FIC_IRQS, - 1, fic->name, + 1, of_node_full_name(fic->node), handle_level_irq, 0, 0, IRQ_GC_INIT_MASK_CACHE); if (ret) { @@ -175,9 +175,8 @@ static int al_fic_register(struct device_node *node, /* * al_fic_wire_init() - initialize and configure fic in wire mode - * @of_node: optional pointer to interrupt controller's device tree node. + * @node: pointer to the interrupt controller's device tree node * @base: mmio to fic register - * @name: name of the fic * @parent_irq: interrupt of parent * * This API will configure the fic hardware to work in wire mode. @@ -187,7 +186,6 @@ static int al_fic_register(struct device_node *node, */ static struct al_fic *al_fic_wire_init(struct device_node *node, void __iomem *base, - const char *name, unsigned int parent_irq) { struct al_fic *fic; @@ -200,7 +198,7 @@ static struct al_fic *al_fic_wire_init(struct device_node *node, fic->base = base; fic->parent_irq = parent_irq; - fic->name = name; + fic->node = node; /* mask out all interrupts */ writel_relaxed(0xFFFFFFFF, fic->base + AL_FIC_MASK); @@ -254,7 +252,6 @@ static int __init al_fic_init_dt(struct device_node *node, fic = al_fic_wire_init(node, base, - node->name, parent_irq); if (IS_ERR(fic)) { pr_err("%pOF: fail to initialize irqchip (%lu)\n", -- 2.47.3