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 08EDBC77B78 for ; Tue, 18 Apr 2023 12:29:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231480AbjDRM3X (ORCPT ); Tue, 18 Apr 2023 08:29:23 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40200 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231553AbjDRM3S (ORCPT ); Tue, 18 Apr 2023 08:29:18 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BACBEBBA9 for ; Tue, 18 Apr 2023 05:28:57 -0700 (PDT) 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 dfw.source.kernel.org (Postfix) with ESMTPS id 9B33F63186 for ; Tue, 18 Apr 2023 12:28:57 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id AAA75C433EF; Tue, 18 Apr 2023 12:28:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1681820937; bh=x3fMCb9BaSePBgl0HRh0ADXMOv6oYhfANuaNwauPeOU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=pGh7v/GZzmBFkS5doXM7C6dyt8cSXy5PUZeb2FXjQ8890l0Kk56k0I1P67ffkzvbQ FChjg9Uv7wtaX5WlkIMhFu5RrIe84vr2TXOIe+oWMMmvjNxBjhwDW8zazADQ6Erar3 jZakHZaY5gOHeV0/AT6BCNsNHnx39g4PWEUxEbH8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, stable , Sherry Sun Subject: [PATCH 5.4 29/92] tty: serial: fsl_lpuart: avoid checking for transfer complete when UARTCTRL_SBK is asserted in lpuart32_tx_empty Date: Tue, 18 Apr 2023 14:21:04 +0200 Message-Id: <20230418120305.868845056@linuxfoundation.org> X-Mailer: git-send-email 2.40.0 In-Reply-To: <20230418120304.658273364@linuxfoundation.org> References: <20230418120304.658273364@linuxfoundation.org> User-Agent: quilt/0.67 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 From: Sherry Sun commit 9425914f3de6febbd6250395f56c8279676d9c3c upstream. According to LPUART RM, Transmission Complete Flag becomes 0 if queuing a break character by writing 1 to CTRL[SBK], so here need to avoid checking for transmission complete when UARTCTRL_SBK is asserted, otherwise the lpuart32_tx_empty may never get TIOCSER_TEMT. Commit 2411fd94ceaa("tty: serial: fsl_lpuart: skip waiting for transmission complete when UARTCTRL_SBK is asserted") only fix it in lpuart32_set_termios(), here also fix it in lpuart32_tx_empty(). Fixes: 380c966c093e ("tty: serial: fsl_lpuart: add 32-bit register interface support") Cc: stable Signed-off-by: Sherry Sun Link: https://lore.kernel.org/r/20230323054415.20363-1-sherry.sun@nxp.com Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/fsl_lpuart.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) --- a/drivers/tty/serial/fsl_lpuart.c +++ b/drivers/tty/serial/fsl_lpuart.c @@ -807,11 +807,17 @@ static unsigned int lpuart32_tx_empty(st struct lpuart_port, port); unsigned long stat = lpuart32_read(port, UARTSTAT); unsigned long sfifo = lpuart32_read(port, UARTFIFO); + unsigned long ctrl = lpuart32_read(port, UARTCTRL); if (sport->dma_tx_in_progress) return 0; - if (stat & UARTSTAT_TC && sfifo & UARTFIFO_TXEMPT) + /* + * LPUART Transmission Complete Flag may never be set while queuing a break + * character, so avoid checking for transmission complete when UARTCTRL_SBK + * is asserted. + */ + if ((stat & UARTSTAT_TC && sfifo & UARTFIFO_TXEMPT) || ctrl & UARTCTRL_SBK) return TIOCSER_TEMT; return 0;