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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 708F2C64ED8 for ; Mon, 27 Feb 2023 07:16:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229602AbjB0HQi (ORCPT ); Mon, 27 Feb 2023 02:16:38 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38520 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229451AbjB0HQh (ORCPT ); Mon, 27 Feb 2023 02:16:37 -0500 Received: from mail-wr1-x433.google.com (mail-wr1-x433.google.com [IPv6:2a00:1450:4864:20::433]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6923A1C307 for ; Sun, 26 Feb 2023 23:16:36 -0800 (PST) Received: by mail-wr1-x433.google.com with SMTP id v16so2278918wrn.0 for ; Sun, 26 Feb 2023 23:16:36 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-disposition:mime-version:message-id:subject:cc:to:from:date :from:to:cc:subject:date:message-id:reply-to; bh=yJr9uKOfN/wZLR1mjPtbvwdEWkA72spRbsMlk4YNxoc=; b=YBlYK6qW9MwoEOWCrgLEV7YcFEF5tO/uQm7XRA0CFwj94VyDfmycfJaHrVOj4Oo7Oa zVkBu1lbgJWBI1Iz+Ds6FCONMK38S6KnSmufyCPEcUiA3RVPC6lQGBy2g27BHNAdLR1j 1YLqTy8OBV658ALBVue/oVEfqZ+B5tB1sQHfZrzOgNVjbRbOfoOf8v+BLGuoquZsQ4tS ipP1yjgysSb8JOP7HKQHCrx+R5J0BsjKdyJxCctKZ5jGVZ5IpR92h+up341gRS5SqH8S K02n+N2/sHSIZQyaYzNNY+wEv+Lirc9QRCUy73kO6CqZ3Vm0ji1beHMIUXS00rlIUXdc 2+dw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-disposition:mime-version:message-id:subject:cc:to:from:date :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=yJr9uKOfN/wZLR1mjPtbvwdEWkA72spRbsMlk4YNxoc=; b=UKyhKRKdIroDLmf2+bcJwq3rgAQEJ7UIBeiE5r0c4SnwaT8qKpsfYXvyEbo5iqTOVT 1FqipmSc/oVzDeYxEX2io+qSPm9qSNaQDsNgrHd4dUcR4KkxZhVSnsD9nTM3Zv46XkPC ev9tKv+sxRyRaON7/yHFZ1AwznhPEpbQZiyGH5wGSqZFj15YM69cUGUk5ZzkQ+bTy/LZ 2ocgwVvPxtkAUlCBDcDodQEcWi2q4aNc1bRAutzvbe8A+8UkVajM978Y2ZFLur0IK1J6 1UQEZrzs8HYouE5TfLQpHBXqEabVmGBZkhwAvTEPJTEXzr5YqscAd7qTuDKmWV2y3lv7 2ymQ== X-Gm-Message-State: AO0yUKVKojwVgoOafYDcLcGM2j4t8KjO19ze/oiG2t3NQDgdnrVHqMPL HuGhhzeP0axGVFNjpuFBMUA= X-Google-Smtp-Source: AK7set8QOFzabs6Yyabd3YcaZf9jPc3ekN2vqrecFRH/2T4klLHidHjta2W5EiGmTeKXhiaoHO22+A== X-Received: by 2002:a5d:58d9:0:b0:2c5:5fb0:b215 with SMTP id o25-20020a5d58d9000000b002c55fb0b215mr19399072wrf.30.1677482194747; Sun, 26 Feb 2023 23:16:34 -0800 (PST) Received: from localhost ([102.36.222.112]) by smtp.gmail.com with ESMTPSA id f7-20020adffcc7000000b002c7163660a9sm6381416wrs.105.2023.02.26.23.16.33 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 26 Feb 2023 23:16:34 -0800 (PST) Date: Mon, 27 Feb 2023 10:16:30 +0300 From: Dan Carpenter To: johan@kernel.org Cc: linux-serial@vger.kernel.org Subject: [bug report] serial: 8250: fix handle_irq locking Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Precedence: bulk List-ID: X-Mailing-List: linux-serial@vger.kernel.org Hello Johan Hovold, The patch 853a9ae29e97: "serial: 8250: fix handle_irq locking" from Jul 14, 2021, leads to the following Smatch static checker warning: drivers/tty/serial/8250/8250_fsl.c:84 fsl8250_handle_irq() warn: inconsistent returns 'flags'. Locked on : 38,46 Unlocked on: 84 drivers/tty/serial/8250/8250_fsl.c 26 int fsl8250_handle_irq(struct uart_port *port) 27 { 28 unsigned long flags; 29 u16 lsr, orig_lsr; 30 unsigned int iir; 31 struct uart_8250_port *up = up_to_u8250p(port); 32 33 spin_lock_irqsave(&up->port.lock, flags); ^^^^^ 34 35 iir = port->serial_in(port, UART_IIR); 36 if (iir & UART_IIR_NO_INT) { 37 spin_unlock(&up->port.lock); 38 return 0; Needs to enable IRQs again. Same below etc. 39 } 40 41 /* This is the WAR; if last event was BRK, then read and return */ 42 if (unlikely(up->lsr_saved_flags & UART_LSR_BI)) { 43 up->lsr_saved_flags &= ~UART_LSR_BI; 44 port->serial_in(port, UART_RX); 45 spin_unlock(&up->port.lock); 46 return 1; 47 } 48 regards, dan carpenter