From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bich HEMON Subject: [PATCH 10/20] serial: stm32: fix dma receive 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> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 8BIT Return-path: In-Reply-To: <1498481318-1894-1-git-send-email-bich.hemon-qxv4g6HH51o@public.gmane.org> Content-Language: en-US Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Greg Kroah-Hartman , Rob Herring , Mark Rutland , Maxime Coquelin , Alexandre TORGUE , Jiri Slaby , "linux-serial-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org" , "linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" Cc: Bich HEMON List-Id: linux-serial@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 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html