From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2A0D2C4BA0E for ; Wed, 26 Feb 2020 10:36:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E7FFD20801 for ; Wed, 26 Feb 2020 10:36:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582713373; bh=Alw7z278SGLxm1mCFyConHmQ0NDOO/At+Kk/iWsp4QU=; h=Subject:To:Cc:From:Date:List-ID:From; b=Gq3+lcsaFnp4toOmq3gxbnv1QDG5FCfSQ4XRQP6XidNvywgwtjY25IKRZweMpAjoc fP9zJsir2GZEFGx1K5fG4bBbH/hLAUlWAOOTcM55DgooHE8EQFzuw7g6+6PT0yJnaQ 53EQbuAsSagxEEyyhwt4MyawILn4hwNPGgn+7e9Y= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727362AbgBZKgM (ORCPT ); Wed, 26 Feb 2020 05:36:12 -0500 Received: from wout2-smtp.messagingengine.com ([64.147.123.25]:50881 "EHLO wout2-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726057AbgBZKgM (ORCPT ); Wed, 26 Feb 2020 05:36:12 -0500 Received: from compute6.internal (compute6.nyi.internal [10.202.2.46]) by mailout.west.internal (Postfix) with ESMTP id 371356D4; Wed, 26 Feb 2020 05:36:11 -0500 (EST) Received: from mailfrontend2 ([10.202.2.163]) by compute6.internal (MEProxy); Wed, 26 Feb 2020 05:36:11 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-transfer-encoding:content-type :date:from:message-id:mime-version:subject:to:x-me-proxy :x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s=fm2; bh=vH2ybk ycEZH1DCxfWcbulVVF3Oq6q2im/FqlYYCEQ+0=; b=1wtM2Xy2Y0j7bQLAtWvoDP LoT84ERQ6U6Jug+xMnEFH7f/DuyfPRHLqymcGDzJgxyLxlP3He6kB+uM6SlpgkQ8 qoY2q3+44vkCTmQjZS1HLZWu8auFnr53xqe9U+NXQK/DsCKxzp3PvpGuEU5Rlw55 E4IW4XL7/G4QXce9fiME6XeDDpAnQ03ZyO6DHB250pK+c8oBmdesHG7NjtGD+Dpy mTs2+Wk3QvnKHfPV/twOhSf+6LUHy+NOSnCC6htLFj+RW/05KNOC1PLrh1PqNE3w jxxlzO+uggALoUCB9hHTLWBbJZMs5mmyaBGWftESnchwNYQtuQX7cBkGt0p48q2Q == X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedugedrleeggddukecutefuodetggdotefrodftvf curfhrohhfihhlvgemucfhrghsthforghilhdpqfgfvfdpuffrtefokffrpgfnqfghnecu uegrihhlohhuthemuceftddtnecunecujfgurhepuffvhfffkfggtgfgsehtkeertddttd flnecuhfhrohhmpeeoghhrvghgkhhhsehlihhnuhigfhhouhhnuggrthhiohhnrdhorhhg qeenucffohhmrghinhepkhgvrhhnvghlrdhorhhgnecukfhppeekfedrkeeirdekledrud dtjeenucevlhhushhtvghrufhiiigvpeefnecurfgrrhgrmhepmhgrihhlfhhrohhmpehg rhgvgheskhhrohgrhhdrtghomh X-ME-Proxy: Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) by mail.messagingengine.com (Postfix) with ESMTPA id 75C663060FDD; Wed, 26 Feb 2020 05:36:10 -0500 (EST) Subject: FAILED: patch "[PATCH] serial: 8250: Check UPF_IRQ_SHARED in advance" failed to apply to 4.4-stable tree To: andriy.shevchenko@linux.intel.com, gregkh@linuxfoundation.org, kurt@linutronix.de, lirongqing@baidu.com, stable@vger.kernel.org, vikram.pandita@ti.com Cc: From: Date: Wed, 26 Feb 2020 11:36:07 +0100 Message-ID: <158271336721122@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org The patch below does not apply to the 4.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 7febbcbc48fc92e3f33863b32ed715ba4aff18c4 Mon Sep 17 00:00:00 2001 From: Andy Shevchenko Date: Tue, 11 Feb 2020 15:55:59 +0200 Subject: [PATCH] serial: 8250: Check UPF_IRQ_SHARED in advance The commit 54e53b2e8081 ("tty: serial: 8250: pass IRQ shared flag to UART ports") nicely explained the problem: ---8<---8<--- On some systems IRQ lines between multiple UARTs might be shared. If so, the irqflags have to be configured accordingly. The reason is: The 8250 port startup code performs IRQ tests *before* the IRQ handler for that particular port is registered. This is performed in serial8250_do_startup(). This function checks whether IRQF_SHARED is configured and only then disables the IRQ line while testing. This test is performed upon each open() of the UART device. Imagine two UARTs share the same IRQ line: On is already opened and the IRQ is active. When the second UART is opened, the IRQ line has to be disabled while performing IRQ tests. Otherwise an IRQ might handler might be invoked, but the IRQ itself cannot be handled, because the corresponding handler isn't registered, yet. That's because the 8250 code uses a chain-handler and invokes the corresponding port's IRQ handling routines himself. Unfortunately this IRQF_SHARED flag isn't configured for UARTs probed via device tree even if the IRQs are shared. This way, the actual and shared IRQ line isn't disabled while performing tests and the kernel correctly detects a spurious IRQ. So, adding this flag to the DT probe solves the issue. Note: The UPF_SHARE_IRQ flag is configured unconditionally. Therefore, the IRQF_SHARED flag can be set unconditionally as well. Example stack trace by performing `echo 1 > /dev/ttyS2` on a non-patched system: |irq 85: nobody cared (try booting with the "irqpoll" option) | [...] |handlers: |[] irq_default_primary_handler threaded [] serial8250_interrupt |Disabling IRQ #85 ---8<---8<--- But unfortunately didn't fix the root cause. Let's try again here by moving IRQ flag assignment from serial_link_irq_chain() to serial8250_do_startup(). This should fix the similar issue reported for 8250_pnp case. Since this change we don't need to have custom solutions in 8250_aspeed_vuart and 8250_of drivers, thus, drop them. Fixes: 1c2f04937b3e ("serial: 8250: add IRQ trigger support") Reported-by: Li RongQing Cc: Kurt Kanzenbach Cc: Vikram Pandita Signed-off-by: Andy Shevchenko Cc: stable Acked-by: Kurt Kanzenbach Link: https://lore.kernel.org/r/20200211135559.85960-1-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman diff --git a/drivers/tty/serial/8250/8250_aspeed_vuart.c b/drivers/tty/serial/8250/8250_aspeed_vuart.c index d657aa14c3e4..c33e02cbde93 100644 --- a/drivers/tty/serial/8250/8250_aspeed_vuart.c +++ b/drivers/tty/serial/8250/8250_aspeed_vuart.c @@ -446,7 +446,6 @@ static int aspeed_vuart_probe(struct platform_device *pdev) port.port.line = rc; port.port.irq = irq_of_parse_and_map(np, 0); - port.port.irqflags = IRQF_SHARED; port.port.handle_irq = aspeed_vuart_handle_irq; port.port.iotype = UPIO_MEM; port.port.type = PORT_16550A; diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c index 0894a22fd702..f2a33c9082a6 100644 --- a/drivers/tty/serial/8250/8250_core.c +++ b/drivers/tty/serial/8250/8250_core.c @@ -174,7 +174,7 @@ static int serial_link_irq_chain(struct uart_8250_port *up) struct hlist_head *h; struct hlist_node *n; struct irq_info *i; - int ret, irq_flags = up->port.flags & UPF_SHARE_IRQ ? IRQF_SHARED : 0; + int ret; mutex_lock(&hash_mutex); @@ -209,9 +209,8 @@ static int serial_link_irq_chain(struct uart_8250_port *up) INIT_LIST_HEAD(&up->list); i->head = &up->list; spin_unlock_irq(&i->lock); - irq_flags |= up->port.irqflags; ret = request_irq(up->port.irq, serial8250_interrupt, - irq_flags, up->port.name, i); + up->port.irqflags, up->port.name, i); if (ret < 0) serial_do_unlink(i, up); } diff --git a/drivers/tty/serial/8250/8250_of.c b/drivers/tty/serial/8250/8250_of.c index 531ad67395e0..f6687756ec5e 100644 --- a/drivers/tty/serial/8250/8250_of.c +++ b/drivers/tty/serial/8250/8250_of.c @@ -202,7 +202,6 @@ static int of_platform_serial_setup(struct platform_device *ofdev, port->type = type; port->uartclk = clk; - port->irqflags |= IRQF_SHARED; if (of_property_read_bool(np, "no-loopback-test")) port->flags |= UPF_SKIP_TEST; diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c index 430e3467aff7..0325f2e53b74 100644 --- a/drivers/tty/serial/8250/8250_port.c +++ b/drivers/tty/serial/8250/8250_port.c @@ -2177,6 +2177,10 @@ int serial8250_do_startup(struct uart_port *port) } } + /* Check if we need to have shared IRQs */ + if (port->irq && (up->port.flags & UPF_SHARE_IRQ)) + up->port.irqflags |= IRQF_SHARED; + if (port->irq && !(up->port.flags & UPF_NO_THRE_TEST)) { unsigned char iir1; /*