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 D20FF232369; Mon, 10 Mar 2025 17:58:24 +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=1741629504; cv=none; b=WHCcXlLC35XEeTtMikGb+LCNJwgZa2j7ls4ZmzvjHs+Sh8c6IOLPRZkBR5XFjX64fHkWP3xbLfuWGwn4Eyd9RnTxQMzc3KXZzIMB1/vVnXdyfsVfZ6p/nzTm9uZnSxfcKF7xUlPU//LDsuw13PalZzlBDE3HC6Ly4CupXluiKWE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741629504; c=relaxed/simple; bh=+hQ41lycmkIoLPZ9QUHpdM0DckK0orpX4ZPwU9qUZOw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=pyQVAWB81EEkQLCPrBs8HQIKEYK1K8pGpgLpujiLw/qRPoGHr6K6JGrwhKSJg4j8jXrXpUMqCsAA58nADmD9l2MnKX8mc/N7BJScxKiptQ4tSValXUzcPFbOp468Rep/t7t8ZGIku3ZffvB2w40ZO1SN60E46Yn+87dcvqHhOGY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=2P4AXbrW; 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="2P4AXbrW" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5C2C4C4CEE5; Mon, 10 Mar 2025 17:58:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1741629504; bh=+hQ41lycmkIoLPZ9QUHpdM0DckK0orpX4ZPwU9qUZOw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=2P4AXbrWvTu8v3OeYloeCm/DUIjzl91UvGC0/2vnCBRojFJrMGisLQhJchY+jKbh1 a0VEERlfw+gbGVBCsHCPfCh3kaH1LnSgEKKxwVLsRslwL3pEGwpmXuPUeEXvNhUEBj acoZxIXE7tLI0EEIcF84pDXJcCk9QAIvKdJX9ccU= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Claudiu Beznea Subject: [PATCH 5.15 286/620] serial: sh-sci: Do not probe the serial port if its slot in sci_ports[] is in use Date: Mon, 10 Mar 2025 18:02:12 +0100 Message-ID: <20250310170556.902844705@linuxfoundation.org> X-Mailer: git-send-email 2.48.1 In-Reply-To: <20250310170545.553361750@linuxfoundation.org> References: <20250310170545.553361750@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Claudiu Beznea commit 9f7dea875cc7f9c1a56a5c688290634a59cd1420 upstream. In the sh-sci driver, sci_ports[0] is used by earlycon. If the earlycon is still active when sci_probe() is called and the new serial port is supposed to map to sci_ports[0], return -EBUSY to prevent breaking the earlycon. This situation should occurs in debug scenarios, and users should be aware of the potential conflict. Fixes: 0b0cced19ab1 ("serial: sh-sci: Add CONFIG_SERIAL_EARLYCON support") Cc: stable@vger.kernel.org Signed-off-by: Claudiu Beznea Link: https://lore.kernel.org/r/20250116182249.3828577-4-claudiu.beznea.uj@bp.renesas.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/sh-sci.c | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) --- a/drivers/tty/serial/sh-sci.c +++ b/drivers/tty/serial/sh-sci.c @@ -164,6 +164,7 @@ struct sci_port { static struct sci_port sci_ports[SCI_NPORTS]; static unsigned long sci_ports_in_use; static struct uart_driver sci_uart_driver; +static bool sci_uart_earlycon; static inline struct sci_port * to_sci_port(struct uart_port *uart) @@ -3319,6 +3320,7 @@ static int sci_probe_single(struct platf static int sci_probe(struct platform_device *dev) { struct plat_sci_port *p; + struct resource *res; struct sci_port *sp; unsigned int dev_id; int ret; @@ -3348,6 +3350,26 @@ static int sci_probe(struct platform_dev } sp = &sci_ports[dev_id]; + + /* + * In case: + * - the probed port alias is zero (as the one used by earlycon), and + * - the earlycon is still active (e.g., "earlycon keep_bootcon" in + * bootargs) + * + * defer the probe of this serial. This is a debug scenario and the user + * must be aware of it. + * + * Except when the probed port is the same as the earlycon port. + */ + + res = platform_get_resource(dev, IORESOURCE_MEM, 0); + if (!res) + return -ENODEV; + + if (sci_uart_earlycon && sp == &sci_ports[0] && sp->port.mapbase != res->start) + return dev_err_probe(&dev->dev, -EBUSY, "sci_port[0] is used by earlycon!\n"); + platform_set_drvdata(dev, sp); ret = sci_probe_single(dev, dev_id, p, sp); @@ -3446,6 +3468,7 @@ static int __init early_console_setup(st port_cfg.type = type; sci_ports[0].cfg = &port_cfg; sci_ports[0].params = sci_probe_regmap(&port_cfg); + sci_uart_earlycon = true; port_cfg.scscr = sci_serial_in(&sci_ports[0].port, SCSCR); sci_serial_out(&sci_ports[0].port, SCSCR, SCSCR_RE | SCSCR_TE | port_cfg.scscr);