From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 482F33101DE; Mon, 13 Oct 2025 15:23:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760369004; cv=none; b=R+m6DER7fPeqSU7K3l1O5t+OXzoPTRVht+aZ/j/mN04Ky4Z/U68mmcxG3kKZs/gUKE4spFGcSY5KP7KVrcmIyGyAUlQKBV8vtJhaWRFBOzuEU7/8AzG1uTYfseUfEm+0rCdALCEMeqd/csZ0u3J3MsqpCkJsPouis3yrVSIsHC0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760369004; c=relaxed/simple; bh=1nqTXgdUz/+m1GqEO1VpPR5FdeFV4+8QhOXZfxKtBEs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=CqaZF10CHzmyPtqE2SLG8WvaAJ2Uvsb16z+PxDZ7NJ961krL8Z8YHgTzYutHv/qjKzCj2oD+v9KAH7+FejpNpIYQ+RwbJ5iaLMyJQhS7LAQN/8bBQjTvDQ/JIHEKumV+5oAHfsetQ35rgLH7uviLcAKX3iOiEsXPBbQXGa2KoGM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=fB8a/hp6; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="fB8a/hp6" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B503BC4CEFE; Mon, 13 Oct 2025 15:23:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1760369004; bh=1nqTXgdUz/+m1GqEO1VpPR5FdeFV4+8QhOXZfxKtBEs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=fB8a/hp6PljwyLfjEco9SkyEffsYVeEF36mlpxe84Vyd7mAxq0iWQ/fnCFpiL4eQ0 RxqxCXE8whppyrTnjfmlDbu/IdbhIso9Rj/1YiQwwAgG542Vn5kwH804ot3LXYEEhl KJvUyHwVL5Sa0ib8qjtGh8N0vTqyWx+9S8pyi2xE= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Junnan Wu , Sudeep Holla , Sasha Levin Subject: [PATCH 6.17 061/563] firmware: arm_scmi: Mark VirtIO ready before registering scmi_virtio_driver Date: Mon, 13 Oct 2025 16:38:42 +0200 Message-ID: <20251013144413.501277971@linuxfoundation.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20251013144411.274874080@linuxfoundation.org> References: <20251013144411.274874080@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 6.17-stable review patch. If anyone has any objections, please let me know. ------------------ From: Junnan Wu [ Upstream commit e8faa8a466f61f4ae07069ed6b0872f602f1cba9 ] After commit 20bda12a0ea0 (“firmware: arm_scmi: Make VirtIO transport a standalone driver”), the VirtIO transport probes independently. During scmi_virtio_probe, scmi_probe() is called, which intune invokes scmi_protocol_acquire() that sends a message over the virtqueue and waits for a reply. Previously, DRIVER_OK was only set after scmi_vio_probe, in the core virtio via virtio_dev_probe(). According to the Virtio spec (3.1 Device Initialization): | The driver MUST NOT send any buffer available notifications to the | device before setting DRIVER_OK. Some type-1 hypervisors block available-buffer notifications until the driver is marked OK. In such cases, scmi_vio_probe stalls in scmi_wait_for_reply(), and the probe never completes. Resolve this by setting DRIVER_OK immediately after the device-specific setup, so scmi_probe() can safely send notifications. Note after splitting the transports into modules, the probe sequence changed a bit. We can no longer rely on virtio_device_ready() being called by the core in virtio_dev_probe(), because scmi_vio_probe() doesn’t complete until the core SCMI stack runs scmi_probe(), which immediately issues the initial BASE protocol exchanges. Fixes: 20bda12a0ea0 ("firmware: arm_scmi: Make VirtIO transport a standalone driver") Signed-off-by: Junnan Wu Message-Id: <20250812075343.3201365-1-junnan01.wu@samsung.com> Signed-off-by: Sudeep Holla Signed-off-by: Sasha Levin --- drivers/firmware/arm_scmi/transports/virtio.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/firmware/arm_scmi/transports/virtio.c b/drivers/firmware/arm_scmi/transports/virtio.c index cb934db9b2b4a..326c4a93e44b9 100644 --- a/drivers/firmware/arm_scmi/transports/virtio.c +++ b/drivers/firmware/arm_scmi/transports/virtio.c @@ -871,6 +871,9 @@ static int scmi_vio_probe(struct virtio_device *vdev) /* Ensure initialized scmi_vdev is visible */ smp_store_mb(scmi_vdev, vdev); + /* Set device ready */ + virtio_device_ready(vdev); + ret = platform_driver_register(&scmi_virtio_driver); if (ret) { vdev->priv = NULL; -- 2.51.0