From patchwork Thu Oct 12 10:23:30 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: pkrasavin@imaqliq.ru X-Patchwork-Id: 13418813 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 69F03CDB46E for ; Thu, 12 Oct 2023 10:24:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:Message-ID:Date:Cc:To:From:Subject: References:In-Reply-To:MIME-Version:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=OOFZndm9Uw+e7wG/Hnsj9p8PSF5p59+F/5xSdrhZe1o=; b=rSjaG0sG6cCSg9 HjmI9WsVcIukqaSM5m6zSM9rV8TRmbxhD7Ij591MxBPAITfAdgX1shIOEZoeR6MmFs3vZUvtrM4bn R79PUgGYJ9BVDCR1ZddpOMwjby5VTvuu6Ydq1sOGPjquzqI/tJ/HCmoJ8j0Bhvf7V6bOx5yfk7STl 6uwk+gXOyCoU9j9LS4PjviaLrl2pV3V2vJBDbOGZmJuE69/8GpFJlICIRPMsgiHUhxCxw+I1RWewg DRjZMH3IlSttUjIhKcKmO+xRbXd6826lCeB2WZ+/3tNbugIb7Zpn51a9YS41dQZCO31xri0wmUuCb 2SA3bX8wLAZma1e8h2vQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qqsr7-000ebk-25; Thu, 12 Oct 2023 10:23:49 +0000 Received: from postfix2.imaqliq.com ([93.189.151.48]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1qqsr3-000eZu-2R; Thu, 12 Oct 2023 10:23:48 +0000 Received: from verse.imaqliq.com (verse.imaqliq.com [93.189.151.95]) by postfix2.imaqliq.com (Postfix) with ESMTP id 4A93A1C2941; Thu, 12 Oct 2023 13:23:36 +0300 (MSK) MIME-Version: 1.0 Sensitivity: Importance: Normal X-Priority: 3 (Normal) In-Reply-To: References: Subject: [PATCH] tty: serial: meson: hard LOCKUP on crtscts mode From: pkrasavin@imaqliq.ru To: Greg Kroah-Hartman , Jiri Slaby , Neil Armstrong , Kevin Hilman , Jerome Brunet , Martin Blumenstingl Cc: linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-amlogic@lists.infradead.org, pkrasavin@imaqliq.ru Date: Thu, 12 Oct 2023 10:23:30 +0000 Message-ID: X-Mailer: Lotus Domino Web Server Release 12.0.2 November 03, 2022 X-MIMETrack: Serialize by http on verse/com(Release 12.0.2|November 03, 2022) at 10/12/2023 10:23:30, Serialize complete at 10/12/2023 10:23:30, Serialize by Router on verse/com(Release 12.0.2|November 03, 2022) at 10/12/2023 10:23:35 X-KeepSent: 28B2B8C9:5BC0CD28-00258A46:0037688F; type=4; name=$KeepSent X-KLMS-Rule-ID: 1 X-KLMS-Message-Action: clean X-KLMS-AntiSpam-Lua-Profiles: 180559 [Oct 12 2023] X-KLMS-AntiSpam-Version: 6.0.0.2 X-KLMS-AntiSpam-Envelope-From: pkrasavin@imaqliq.ru X-KLMS-AntiSpam-Rate: 10 X-KLMS-AntiSpam-Status: not_detected X-KLMS-AntiSpam-Method: none X-KLMS-AntiSpam-Auth: dmarc=fail header.from=imaqliq.ru policy=none;spf=softfail smtp.mailfrom=imaqliq.ru;dkim=none X-KLMS-AntiSpam-Info: LuaCore: 539 539 807534d9021bfe9ca369c363d15ac993cd93d4d9, {rep_avail}, {Tracking_from_domain_doesnt_match_to}, d41d8cd98f00b204e9800998ecf8427e.com:7.1.1;gdc.ru:7.1.1;127.0.0.199:7.1.2;imaqliq.ru:7.1.1;verse.imaqliq.com:7.1.1;93.189.151.95:7.1.2, FromAlignment: s, {Tracking_dmark_f}, ApMailHostAddress: 93.189.151.95 X-MS-Exchange-Organization-SCL: -1 X-KLMS-AntiSpam-Interceptor-Info: scan successful X-KLMS-AntiPhishing: Clean, bases: 2023/10/12 08:55:00 X-KLMS-AntiVirus: Kaspersky Security for Linux Mail Server, version 8.0.3.30, bases: 2023/10/12 01:34:00 #22164647 X-KLMS-AntiVirus-Status: Clean, skipped X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20231012_032346_148445_95422822 X-CRM114-Status: UNSURE ( 8.88 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org There might be hard lockup if we set crtscts mode on port without RTS/CTS configured: # stty -F /dev/ttyAML6 crtscts; echo 1 > /dev/ttyAML6; echo 2 > /dev/ttyAML6 [ 95.890386] rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: [ 95.890857] rcu: 3-...0: (201 ticks this GP) idle=e33c/1/0x4000000000000000 softirq=5844/5846 fqs=4984 [ 95.900212] rcu: (detected by 2, t=21016 jiffies, g=7753, q=296 ncpus=4) [ 95.906972] Task dump for CPU 3: [ 95.910178] task:bash state:R running task stack:0 pid:205 ppid:1 flags:0x00000202 [ 95.920059] Call trace: [ 95.922485] __switch_to+0xe4/0x168 [ 95.925951] 0xffffff8003477508 [ 95.974379] watchdog: Watchdog detected hard LOCKUP on cpu 3 [ 95.974424] Modules linked in: 88x2cs(O) rtc_meson_vrtc Possible solution would be to not allow to setup crtscts on such port. Tested on S905X3 based board. Signed-off-by: Pavel Krasavin --- a/drivers/tty/serial/meson_uart.c 2023-08-22 12:46:50.933814528 +0300 +++ b/drivers/tty/serial/meson_uart.c 2023-08-22 14:48:15.593169948 +0300 @@ -380,10 +380,15 @@ static void meson_uart_set_termios(struc else val |= AML_UART_STOP_BIT_1SB; - if (cflags & CRTSCTS) - val &= ~AML_UART_TWO_WIRE_EN; - else + if (cflags & CRTSCTS) { + if (port->flags & UPF_HARD_FLOW) { + val &= ~AML_UART_TWO_WIRE_EN; + } else { + termios->c_cflag &= ~CRTSCTS; + } + } else { val |= AML_UART_TWO_WIRE_EN; + } writel(val, port->membase + AML_UART_CONTROL); @@ -705,6 +710,7 @@ static int meson_uart_probe(struct platf u32 fifosize = 64; /* Default is 64, 128 for EE UART_0 */ int ret = 0; int irq; + bool has_rtscts; if (pdev->dev.of_node) pdev->id = of_alias_get_id(pdev->dev.of_node, "serial"); @@ -732,6 +738,7 @@ static int meson_uart_probe(struct platf return irq; of_property_read_u32(pdev->dev.of_node, "fifo-size", &fifosize); + has_rtscts = of_property_read_bool(pdev->dev.of_node, "uart-has-rtscts"); if (meson_ports[pdev->id]) { return dev_err_probe(&pdev->dev, -EBUSY, @@ -762,6 +769,8 @@ static int meson_uart_probe(struct platf port->mapsize = resource_size(res_mem); port->irq = irq; port->flags = UPF_BOOT_AUTOCONF | UPF_LOW_LATENCY; + if (has_rtscts) + port->flags |= UPF_HARD_FLOW; port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_MESON_CONSOLE); port->dev = &pdev->dev; port->line = pdev->id;