From nobody Sun Feb 8 10:41:32 2026 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) (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 0848118AED; Tue, 13 Feb 2024 08:39:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=193.142.43.55 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707813599; cv=none; b=a5Kot4nBSZ236qLHd2olGt2dK9nL0u9IqijClLlCgZlgAzB87ta8cJP7we6lylyWRHJusr73P0smYht7pfQSaGBMZmhkrdUHbEMAS06rtfj02pSF2d0xqUiJSx5Hrswnz/PPC3MNtxkn+rNHtnjMaqLwUElh6kXqEYZI6pBNdN0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707813599; c=relaxed/simple; bh=FUVFlKXHErfQHwVS12HqcrL/BlrR/XNwXJub9R1UUnU=; h=Date:From:To:Subject:Cc:In-Reply-To:References:MIME-Version: Message-ID:Content-Type; b=G7v+x5ePbIRzfpmjiH/NMnjre8W212Ezmb0GrFQeTiO0qVDgKCKIcWDxwjKHn/fV4K2F8Vc3NlnetDz3taVy/xJaBXK6XKjSciWXCxDcL+UIFMuJ4BBAhPL9dHfJTfGnBm8GSbVZ5Cy8PXXlGrCdg/BxLK4z0gMzvB5TiLpb/KU= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de; spf=pass smtp.mailfrom=linutronix.de; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=FqR3nORj; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=AQiCdoC+; arc=none smtp.client-ip=193.142.43.55 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linutronix.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="FqR3nORj"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="AQiCdoC+" Date: Tue, 13 Feb 2024 08:39:48 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1707813589; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=/ormm+PHwLi/CeFwP1A2naAwgJmnQBsAxeCyqCbJneM=; b=FqR3nORjlwLo57t5FFCrDcJZrZ4kYwEPfnB3zBdljb27/X2S0xX2X5N9SihSn1NQc9+p9m 12UEu3gOC/PC2sb6lV3CuXbn8mqNt8AMMAPV3WNrfbZEI8XcwJ9zIhvPidWnUoUFqjOGuQ +8U7Cm4V92KF+hRjVZgBSudaUg2Duvu0F5iiDiuXePDzd/mFQB9Jyhfid2cYIrHswjx/rD hAfHK/1MqrD+uuYJ3rcd0ls5zadun6mlaxl0VtpKH1LYRHZQEibyq/5ZfSkL7rT7K12TVb +ttOU/0+i2PePC6ldcfzwpvzrfj42b+AE8+Tjxg7IyrIGuVci29LO/ONtE/VTg== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1707813589; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=/ormm+PHwLi/CeFwP1A2naAwgJmnQBsAxeCyqCbJneM=; b=AQiCdoC+rhHsjRbWwMJIAPgzekYzRRp3O89tm1Qz4JWgVsOPYnTU2xrjeKYHUV6+j9Tvbq 10p9R4wWT1wFTHBg== From: "tip-bot2 for Doug Berger" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: irq/urgent] irqchip/irq-brcmstb-l2: Add write memory barrier before exit Cc: Doug Berger , Florian Fainelli , Thomas Gleixner , Marc Zyngier , stable@vger.kernel.org, x86@kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <20240210012449.3009125-1-florian.fainelli@broadcom.com> References: <20240210012449.3009125-1-florian.fainelli@broadcom.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-ID: <170781358867.398.2362878690950793714.tip-bot2@tip-bot2> Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Precedence: bulk Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable The following commit has been merged into the irq/urgent branch of tip: Commit-ID: b0344d6854d25a8b3b901c778b1728885dd99007 Gitweb: https://git.kernel.org/tip/b0344d6854d25a8b3b901c778b1728885= dd99007 Author: Doug Berger AuthorDate: Fri, 09 Feb 2024 17:24:49 -08:00 Committer: Thomas Gleixner CommitterDate: Tue, 13 Feb 2024 09:33:31 +01:00 irqchip/irq-brcmstb-l2: Add write memory barrier before exit It was observed on Broadcom devices that use GIC v3 architecture L1 interrupt controllers as the parent of brcmstb-l2 interrupt controllers that the deactivation of the parent interrupt could happen before the brcmstb-l2 deasserted its output. This would lead the GIC to reactivate the interrupt only to find that no L2 interrupt was pending. The result was a spurious interrupt invoking handle_bad_irq() with its associated messaging. While this did not create a functional problem it is a waste of cycles. The hazard exists because the memory mapped bus writes to the brcmstb-l2 registers are buffered and the GIC v3 architecture uses a very efficient system register write to deactivate the interrupt. Add a write memory barrier prior to invoking chained_irq_exit() to introduce a dsb(st) on those systems to ensure the system register write cannot be executed until the memory mapped writes are visible to the system. [ florian: Added Fixes tag ] Fixes: 7f646e92766e ("irqchip: brcmstb-l2: Add Broadcom Set Top Box Level-= 2 interrupt controller") Signed-off-by: Doug Berger Signed-off-by: Florian Fainelli Signed-off-by: Thomas Gleixner Acked-by: Florian Fainelli Acked-by: Marc Zyngier Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20240210012449.3009125-1-florian.fainelli@b= roadcom.com --- drivers/irqchip/irq-brcmstb-l2.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/irqchip/irq-brcmstb-l2.c b/drivers/irqchip/irq-brcmstb= -l2.c index 5559c94..2b0b317 100644 --- a/drivers/irqchip/irq-brcmstb-l2.c +++ b/drivers/irqchip/irq-brcmstb-l2.c @@ -2,7 +2,7 @@ /* * Generic Broadcom Set Top Box Level 2 Interrupt controller driver * - * Copyright (C) 2014-2017 Broadcom + * Copyright (C) 2014-2024 Broadcom */ =20 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt @@ -112,6 +112,9 @@ static void brcmstb_l2_intc_irq_handle(struct irq_desc = *desc) generic_handle_domain_irq(b->domain, irq); } while (status); out: + /* Don't ack parent before all device writes are done */ + wmb(); + chained_irq_exit(chip, desc); }