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,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 54B2DC742B9 for ; Fri, 12 Jul 2019 12:36:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 24C1F2166E for ; Fri, 12 Jul 2019 12:36:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1562934978; bh=nkZ6Tz3khAsmsQ82x8OX7tgmPnhebC4vG3Vhlk1ApSY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=QSom/9wQKDFeNHCe3CUpZUtG9XdTqgRp3sbBUwsj5bs18sbSi4LhOuUVfG2Z/Hcn+ cpmpRYHquk/Yj/OY60ATCA/MAYq7x/VcupuuOpV5OFPv0IBT8ANzlvm7ve0LrEGLqd b5P4beOUWItEckHVIVGK52k+lUVw15p4nvSdZSuM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728921AbfGLMcz (ORCPT ); Fri, 12 Jul 2019 08:32:55 -0400 Received: from mail.kernel.org ([198.145.29.99]:51466 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728842AbfGLMcy (ORCPT ); Fri, 12 Jul 2019 08:32:54 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 389C321019; Fri, 12 Jul 2019 12:32:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1562934773; bh=nkZ6Tz3khAsmsQ82x8OX7tgmPnhebC4vG3Vhlk1ApSY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=q6fc5PN8GA1ib/l3X3u8M/DeS+Q+oZJ677XIHpmbz7LoDP13qPjlzb6FmarB/5iEG WShvcQefqmD8FDQomBM/P2XELxKjuYbzIXoa97hTcdJOH8C/0cKNg7+j5yNQohwi3B Qin3bbRTO/vFXhcrvE4UdnJ0IMX2ntzx7i8G0IdY= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Oliver Barta , Andy Shevchenko Subject: [PATCH 5.2 26/61] Revert "serial: 8250: Dont service RX FIFO if interrupts are disabled" Date: Fri, 12 Jul 2019 14:19:39 +0200 Message-Id: <20190712121622.030062321@linuxfoundation.org> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190712121620.632595223@linuxfoundation.org> References: <20190712121620.632595223@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Oliver Barta commit 3f2640ed7be838c3f05c0d2b0f7c7508e7431e48 upstream. This reverts commit 2e9fe539108320820016f78ca7704a7342788380. Reading LSR unconditionally but processing the error flags only if UART_IIR_RDI bit was set before in IIR may lead to a loss of transmission error information on UARTs where the transmission error flags are cleared by a read of LSR. Information are lost in case an error is detected right before the read of LSR while processing e.g. an UART_IIR_THRI interrupt. Signed-off-by: Oliver Barta Reviewed-by: Andy Shevchenko Fixes: 2e9fe5391083 ("serial: 8250: Don't service RX FIFO if interrupts are disabled") Cc: stable Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/8250/8250_port.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) --- a/drivers/tty/serial/8250/8250_port.c +++ b/drivers/tty/serial/8250/8250_port.c @@ -1869,8 +1869,7 @@ int serial8250_handle_irq(struct uart_po status = serial_port_in(port, UART_LSR); - if (status & (UART_LSR_DR | UART_LSR_BI) && - iir & UART_IIR_RDI) { + if (status & (UART_LSR_DR | UART_LSR_BI)) { if (!up->dma || handle_rx_dma(up, iir)) status = serial8250_rx_chars(up, status); }