From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AB8JxZpXVEOwCDBbpwuRIYImT2fEIr8SKc6d5CRaMKItNOSeWvVmkfXO6igIJTPKPEHoWK7GiHyK ARC-Seal: i=1; a=rsa-sha256; t=1527156322; cv=none; d=google.com; s=arc-20160816; b=mUBY/TedU/OUvVd2vZ/0pI8YRSBP8hHbE+qnaYnRM5z1g9Mmh1chDlHdvvolhQoV3y mIgsNmSbrD4ameJAVPAvGddEOTlEH6Ei8DNT4qWYnfZRTheFEjBEuTJx8/I4s16WtOfP SgYyhqqbmPwdoFvz3K9qEkyv+pdnzOO9BiAzocF0VGX8sXgtbvI8Hhaaz0HLX3hkQZEy yfoe+v8yqxzzyfP3bWJf15seii2IBqidAXH3LF71WOTQV72cxS/heiaoE/hKY8ywzaXP x05VZb9KJwuBvePNfFF5dqCDqRaiN2PCkJSwbs9NtCh6pOoDwJ46/Ui8wRIR5PZBskFW 2GcQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=mime-version:user-agent:references:in-reply-to:message-id:date :subject:cc:to:from:dkim-signature:arc-authentication-results; bh=myfi9ZX1aton/ZzXK33vFSMR4qGH9WrkpJ+iqPjjsPc=; b=ih9UCuI4QFfqbGtkS8MEDcMLYFjRBajshmXScHzvsYPDw7IHhyvQQ9sKDBst6AsUr3 8Pqc+gfVC4UhQTqYyUEIxk19LTliNbQUlakeS0rxAMH8BgfcbvUCTix5yXbD6srzINyV +Pt42/WV0TvShx8Yn1ljlCvFuo+r8q5Oriqc74u97QIpS8hQViSc0V1w5SnYGAvoKM59 jyl/7Dhj5xHjGzycv+2l4yxR4FR2IZzqU54pABWHYa5Lv/RSGN+MMHbcEDembmbc37Tb Vj0Dw0BBzm/RhzyBvX07G93VznS+5qnw3pqTHdokUtsOZ15DI+fCzrJ86OeyT3rCf+Dv TIGQ== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=Gfz1B1yZ; spf=pass (google.com: domain of srs0=we5z=il=linuxfoundation.org=gregkh@kernel.org designates 198.145.29.99 as permitted sender) smtp.mailfrom=SRS0=We5Z=IL=linuxfoundation.org=gregkh@kernel.org Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=Gfz1B1yZ; spf=pass (google.com: domain of srs0=we5z=il=linuxfoundation.org=gregkh@kernel.org designates 198.145.29.99 as permitted sender) smtp.mailfrom=SRS0=We5Z=IL=linuxfoundation.org=gregkh@kernel.org From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Miquel Raynal , Gregory CLEMENT , Gabriel Matni , Sasha Levin Subject: [PATCH 4.16 145/161] serial: mvebu-uart: fix tx lost characters Date: Thu, 24 May 2018 11:39:30 +0200 Message-Id: <20180524093035.718574153@linuxfoundation.org> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20180524093018.331893860@linuxfoundation.org> References: <20180524093018.331893860@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-LABELS: =?utf-8?b?IlxcU2VudCI=?= X-GMAIL-THRID: =?utf-8?q?1601339468039636639?= X-GMAIL-MSGID: =?utf-8?q?1601339468039636639?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.16-stable review patch. If anyone has any objections, please let me know. ------------------ From: Gabriel Matni [ Upstream commit c685af1108d7c303f0b901413405d68eaeac4477 ] Fixes missing characters on kernel console at low baud rates (i.e.9600). The driver should poll TX_RDY or TX_FIFO_EMP instead of TX_EMP to ensure that the transmitter holding register (THR) is ready to receive a new byte. TX_EMP tells us when it is possible to send a break sequence via SND_BRK_SEQ. While this also indicates that both the THR and the TSR are empty, it does not guarantee that a new byte can be written just yet. Fixes: 30530791a7a0 ("serial: mvebu-uart: initial support for Armada-3700 serial port") Reviewed-by: Miquel Raynal Acked-by: Gregory CLEMENT Signed-off-by: Gabriel Matni Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/mvebu-uart.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/tty/serial/mvebu-uart.c +++ b/drivers/tty/serial/mvebu-uart.c @@ -617,7 +617,7 @@ static void wait_for_xmitr(struct uart_p u32 val; readl_poll_timeout_atomic(port->membase + UART_STAT, val, - (val & STAT_TX_EMP), 1, 10000); + (val & STAT_TX_RDY(port)), 1, 10000); } static void mvebu_uart_console_putchar(struct uart_port *port, int ch)