From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752140AbdFZMvn convert rfc822-to-8bit (ORCPT ); Mon, 26 Jun 2017 08:51:43 -0400 Received: from mx08-00178001.pphosted.com ([91.207.212.93]:5671 "EHLO mx07-00178001.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752563AbdFZMvW (ORCPT ); Mon, 26 Jun 2017 08:51:22 -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 10/20] serial: stm32: fix dma receive Thread-Topic: [PATCH 10/20] serial: stm32: fix dma receive Thread-Index: AQHS7nqcHZdA4gZzHEOhJbhIr4zCeg== Date: Mon, 26 Jun 2017 12:49:12 +0000 Message-ID: <1498481318-1894-11-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 Two improvements for dma receive in this patch: - usart dma receiver (DMAR) is disabled during receive - dma receive buffer is sync-ed for cpu before reading and given back to the dma just after Signed-off-by: Gerald Baeza --- drivers/tty/serial/stm32-usart.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c index 266dc4f..13fc520 100644 --- a/drivers/tty/serial/stm32-usart.c +++ b/drivers/tty/serial/stm32-usart.c @@ -393,11 +393,21 @@ static irqreturn_t stm32_threaded_interrupt(int irq, void *ptr) { struct uart_port *port = ptr; struct stm32_port *stm32_port = to_stm32_port(port); + struct stm32_usart_offsets *ofs = &stm32_port->info->ofs; spin_lock(&port->lock); - if (stm32_port->rx_ch) + if (stm32_port->rx_ch) { + stm32_clr_bits(port, ofs->cr3, USART_CR3_DMAR); + dma_sync_single_for_cpu(port->dev, + stm32_port->rx_dma_buf, + RX_BUF_L, DMA_FROM_DEVICE); stm32_receive_chars(port, true); + dma_sync_single_for_device(port->dev, + stm32_port->rx_dma_buf, + RX_BUF_L, DMA_FROM_DEVICE); + stm32_set_bits(port, ofs->cr3, USART_CR3_DMAR); + } spin_unlock(&port->lock); -- 1.9.1