From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752701AbdFZMx4 convert rfc822-to-8bit (ORCPT ); Mon, 26 Jun 2017 08:53:56 -0400 Received: from mx07-00178001.pphosted.com ([62.209.51.94]:29029 "EHLO mx07-00178001.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752361AbdFZMuY (ORCPT ); Mon, 26 Jun 2017 08:50:24 -0400 From: Bich HEMON To: Greg Kroah-Hartman , Rob Herring , Mark Rutland , Maxime Coquelin , Alexandre TORGUE , "Jiri Slaby" , "linux-serial@vger.kernel.org" , "devicetree@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" CC: Bich HEMON Subject: [PATCH 20/20] serial: stm32: fix rx interrupt handling in startup Thread-Topic: [PATCH 20/20] serial: stm32: fix rx interrupt handling in startup Thread-Index: AQHS7nqf//JyH38Qx0aCl/bG/bxtpQ== Date: Mon, 26 Jun 2017 12:49:17 +0000 Message-ID: <1498481318-1894-21-git-send-email-bich.hemon@st.com> References: <1498481318-1894-1-git-send-email-bich.hemon@st.com> In-Reply-To: <1498481318-1894-1-git-send-email-bich.hemon@st.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-messagesentrepresentingtype: 1 x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.75.127.50] Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2017-06-26_09:,, signatures=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Bich Hemon When stm32 dma is used, Data register has to be read in order to clear the RXNE interrupt in case we received data before usart probe. Signed-off-by: Bich Hemon --- drivers/tty/serial/stm32-usart.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c index 06a92c8..b1f3aab 100644 --- a/drivers/tty/serial/stm32-usart.c +++ b/drivers/tty/serial/stm32-usart.c @@ -568,9 +568,18 @@ static int stm32_startup(struct uart_port *port) struct stm32_usart_offsets *ofs = &stm32_port->info->ofs; struct stm32_usart_config *cfg = &stm32_port->info->cfg; const char *name = to_platform_device(port->dev)->name; - u32 val; + u32 val, sr, dr; int ret; + sr = readl_relaxed(port->membase + ofs->isr); + + if ((sr & USART_SR_RXNE) && (stm32_port->rx_ch)) + ret = readl_relaxed_poll_timeout_atomic(port->membase + + ofs->rdr, + dr, + !(sr & USART_SR_RXNE), + 10, 100000); + ret = request_threaded_irq(port->irq, stm32_interrupt, stm32_threaded_interrupt, IRQF_NO_SUSPEND, name, port); -- 1.9.1