From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (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 E7CDB39B97F for ; Mon, 4 May 2026 16:35:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777912519; cv=none; b=ClUlN4jwfr3UbzMJqgrO3mchdm87E8Ff9guMpxILLogatwO8/46Qlir+LgDfRMwnoyivG+fzaHzd6wRXdr6C79srObxky6tRbXbdv0BucTzzaBQSHRml7xb0iZAO8tfvDmtU24FW4mPCUFClF1n5ZzddGsL9HhE8ZSdtEtUV8EQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777912519; c=relaxed/simple; bh=RMF2wbDO7Cu7Ode2EIeZxKPPw0UUdDh35IH+0ozJRxE=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=O960MGhF8LBo8AxOpVFtqZmUyADvd8gR0yoHEkav+29wpuaOYOXJIlgC0FgqqgT7jpvCJqIdeV8GGnyJmuNsiBY8z5Ub0LloArcB+ANeGmq+dlZBVWA9gbn8pUg0DNTWmd99b3CpsOfP0X3aeBXKfk2Hio3wspGbSyY/Qo0UORI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=C3oglvce; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="C3oglvce" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1777912516; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=IOVlEIey1KL6W7eekEzWzNHwKHVr2WijrrD98LUvP0s=; b=C3oglvcecBN0z7lwfDcPEamk1nvsAbTa3eogfp6jCIKEt7+OKjdggG/ozeWdcQY8MCOIoU ukq17md7M2Z4ZwYlIMR0xiRlCm+FVfznozKj/L/e2d51UnTLW46jJyMli65hQzwqHpqo9O aAjoZlKxSHbkNvNYnVAmL/fV5ewacMM= Received: from mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-196-AE3on9EYNqKaeRjvsL30WQ-1; Mon, 04 May 2026 12:35:12 -0400 X-MC-Unique: AE3on9EYNqKaeRjvsL30WQ-1 X-Mimecast-MFC-AGG-ID: AE3on9EYNqKaeRjvsL30WQ_1777912511 Received: from mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.17]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 0D2061800578; Mon, 4 May 2026 16:35:11 +0000 (UTC) Received: from llong-thinkpadp16vgen1.westford.csb (unknown [10.2.16.173]) by mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 163731944CED; Mon, 4 May 2026 16:35:07 +0000 (UTC) From: Waiman Long To: Thierry Reding , Jonathan Hunter , Sebastian Andrzej Siewior , Clark Williams , Steven Rostedt Cc: linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org, linux-rt-devel@lists.linux.dev, jberring@redhat.com, Waiman Long Subject: [PATCH] firmware: tegra: bpmp: Make atomic_tx_lock a raw_spinlock Date: Mon, 4 May 2026 12:34:48 -0400 Message-ID: <20260504163448.1063474-1-longman@redhat.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 X-Scanned-By: MIMEDefang 3.0 on 10.30.177.17 The atomic_tx_lock was first introduced by commit 1abb081e41a7 ("firmware: tegra: Simplify channel management") as a spinlock_t. It is used only in tegra_bpmp_transfer_atomic() to ensure mutual exclusion. Since the merging of PREEMPT_RT support into mainline Linux kernel in v6.12, a spinlock becomes a sleeping lock when CONFIG_PREEMPT_RT is enabled. As tegra_bpmp_transfer_atomic() is called with interrupt disabled, acquiring a sleeping lock will lead to the following bug report when booting up a PREEMPT_RT kernel on an tegra based arm64 system with Boot and Power Management Processor (BPMP). BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48 in_atomic(): 0, irqs_disabled(): 1, non_block: 0, pid: 1, name: swapper/0 preempt_count: 0, expected: 0 RCU nest depth: 0, expected: 0 2 locks held by swapper/0/1: #0: ffff42bda2d5b0f0 (&dev->mutex){....}-{3:3}, at: __driver_attach+0x110/0x2c0 #1: ffff42bda4da5138 (&bpmp->atomic_tx_lock){....}-{2:2}, at: tegra_bpmp_transfer_atomic+0x118/0x3c0 Fix it by changing the type of atomic_tx_lock in the tegra_bpmp structure to raw_spinlock_t and use raw_spinlock APIs to access it. Signed-off-by: Waiman Long --- drivers/firmware/tegra/bpmp.c | 8 ++++---- include/soc/tegra/bpmp.h | 2 +- 2 files changed, 5 insertions(+), 5 deletions(-) diff --git a/drivers/firmware/tegra/bpmp.c b/drivers/firmware/tegra/bpmp.c index 753472b53bd8..1a82ce7d340d 100644 --- a/drivers/firmware/tegra/bpmp.c +++ b/drivers/firmware/tegra/bpmp.c @@ -365,16 +365,16 @@ int tegra_bpmp_transfer_atomic(struct tegra_bpmp *bpmp, channel = bpmp->tx_channel; - spin_lock(&bpmp->atomic_tx_lock); + raw_spin_lock(&bpmp->atomic_tx_lock); err = tegra_bpmp_channel_write(channel, msg->mrq, MSG_ACK, msg->tx.data, msg->tx.size); if (err < 0) { - spin_unlock(&bpmp->atomic_tx_lock); + raw_spin_unlock(&bpmp->atomic_tx_lock); return err; } - spin_unlock(&bpmp->atomic_tx_lock); + raw_spin_unlock(&bpmp->atomic_tx_lock); err = tegra_bpmp_ring_doorbell(bpmp); if (err < 0) @@ -763,7 +763,7 @@ static int tegra_bpmp_probe(struct platform_device *pdev) if (!bpmp->threaded.busy) return -ENOMEM; - spin_lock_init(&bpmp->atomic_tx_lock); + raw_spin_lock_init(&bpmp->atomic_tx_lock); bpmp->tx_channel = devm_kzalloc(&pdev->dev, sizeof(*bpmp->tx_channel), GFP_KERNEL); if (!bpmp->tx_channel) diff --git a/include/soc/tegra/bpmp.h b/include/soc/tegra/bpmp.h index a33582590a3b..fdd8739715dc 100644 --- a/include/soc/tegra/bpmp.h +++ b/include/soc/tegra/bpmp.h @@ -79,7 +79,7 @@ struct tegra_bpmp { struct mbox_chan *channel; } mbox; - spinlock_t atomic_tx_lock; + raw_spinlock_t atomic_tx_lock; struct tegra_bpmp_channel *tx_channel, *rx_channel, *threaded_channels; struct { -- 2.53.0