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 78744C433FE for ; Wed, 9 Nov 2022 12:05:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229587AbiKIMFd (ORCPT ); Wed, 9 Nov 2022 07:05:33 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43546 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229590AbiKIMFc (ORCPT ); Wed, 9 Nov 2022 07:05:32 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 446912A728 for ; Wed, 9 Nov 2022 04:05:32 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 05323B81D52 for ; Wed, 9 Nov 2022 12:05:31 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 38DC6C433D7; Wed, 9 Nov 2022 12:05:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1667995529; bh=RYrPeEAqEFoDnzslPebc50kNds0xAUBYjwrWoPTzzj0=; h=Subject:To:From:Date:From; b=n4za5ZCLnWrspkgZg4M9snzH0lSPhFBhN/9A4kuQpIcyjlPs9G7VBm3CxOg/CJPHF 6LV548xGzFhGQVd+dPMlLppi3Qw5aAcS/REpmzoYM/Bxglmnod9xMu88uqEnOJt8YZ fGbLLuYzRdLBwb0ZEcHU4wNMuNIvi3hQsS/vOw98= Subject: patch "serial: 8250: Flush DMA Rx on RLSI" added to tty-linus To: ilpo.jarvinen@linux.intel.com, andriy.shevchenko@linux.intel.com, gregkh@linuxfoundation.org, stable@vger.kernel.org From: Date: Wed, 09 Nov 2022 13:05:12 +0100 Message-ID: <16679955129250@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org This is a note to let you know that I've just added the patch titled serial: 8250: Flush DMA Rx on RLSI to my tty git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty.git in the tty-linus branch. The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.) The patch will hopefully also be merged in Linus's tree for the next -rc kernel release. If you have any questions about this process, please let me know. >From 1980860e0c8299316cddaf0992dd9e1258ec9d88 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Ilpo=20J=C3=A4rvinen?= Date: Tue, 8 Nov 2022 14:19:52 +0200 Subject: serial: 8250: Flush DMA Rx on RLSI MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Returning true from handle_rx_dma() without flushing DMA first creates a data ordering hazard. If DMA Rx has handled any character at the point when RLSI occurs, the non-DMA path handles any pending characters jumping them ahead of those characters that are pending under DMA. Fixes: 75df022b5f89 ("serial: 8250_dma: Fix RX handling") Cc: Signed-off-by: Ilpo Järvinen Reviewed-by: Andy Shevchenko Link: https://lore.kernel.org/r/20221108121952.5497-5-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/8250/8250_port.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c index 92dd18716169..388172289627 100644 --- a/drivers/tty/serial/8250/8250_port.c +++ b/drivers/tty/serial/8250/8250_port.c @@ -1901,10 +1901,9 @@ static bool handle_rx_dma(struct uart_8250_port *up, unsigned int iir) if (!up->dma->rx_running) break; fallthrough; + case UART_IIR_RLSI: case UART_IIR_RX_TIMEOUT: serial8250_rx_dma_flush(up); - fallthrough; - case UART_IIR_RLSI: return true; } return up->dma->rx_dma(up); -- 2.38.1