From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mailout1.w1.samsung.com ([210.118.77.11]:41015 "EHLO mailout1.w1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752435AbdCWHp5 (ORCPT ); Thu, 23 Mar 2017 03:45:57 -0400 From: Marek Szyprowski To: linux-samsung-soc@vger.kernel.org, linux-serial@vger.kernel.org Cc: Marek Szyprowski , Sylwester Nawrocki , Krzysztof Kozlowski , Bartlomiej Zolnierkiewicz , Greg Kroah-Hartman , Seung-Woo Kim , Joonyoung Shim , Inki Dae , stable@vger.kernel.org Subject: [PATCH 2/2] serial: samsung: Add missing checks for dma_map_single failure Date: Thu, 23 Mar 2017 08:45:22 +0100 Message-id: <1490255131-9597-2-git-send-email-m.szyprowski@samsung.com> In-reply-to: <1490255131-9597-1-git-send-email-m.szyprowski@samsung.com> References: <1490255131-9597-1-git-send-email-m.szyprowski@samsung.com> Sender: stable-owner@vger.kernel.org List-ID: This patch adds missing checks for dma_map_single() failure and proper error reporting. While touching this part of the code, it also removes unnecessary spinlock calls around dma_map_single() for TX buffer. This finally solves all the issues reported by DMA API debug framework. Reported-by: Seung-Woo Kim Fixes: 2c37eedb74c8 ("serial: samsung: add dma reqest/release functions") CC: stable@vger.kernel.org # v4.10+ Signed-off-by: Marek Szyprowski --- This issue was there since adding DMA support, but this patch applies cleanly only to v4.10+ kernels due to other changes in the surrounding code. --- drivers/tty/serial/samsung.c | 35 ++++++++++++++++++++++++----------- 1 file changed, 24 insertions(+), 11 deletions(-) diff --git a/drivers/tty/serial/samsung.c b/drivers/tty/serial/samsung.c index 9f3759bdb44f..8aca18c4cdea 100644 --- a/drivers/tty/serial/samsung.c +++ b/drivers/tty/serial/samsung.c @@ -859,7 +859,7 @@ static void s3c24xx_serial_break_ctl(struct uart_port *port, int break_state) static int s3c24xx_serial_request_dma(struct s3c24xx_uart_port *p) { struct s3c24xx_uart_dma *dma = p->dma; - unsigned long flags; + int ret; /* Default slave configuration parameters */ dma->rx_conf.direction = DMA_DEV_TO_MEM; @@ -884,8 +884,8 @@ static int s3c24xx_serial_request_dma(struct s3c24xx_uart_port *p) dma->tx_chan = dma_request_chan(p->port.dev, "tx"); if (IS_ERR(dma->tx_chan)) { - dma_release_channel(dma->rx_chan); - return PTR_ERR(dma->tx_chan); + ret = PTR_ERR(dma->tx_chan); + goto err_release_rx; } dmaengine_slave_config(dma->tx_chan, &dma->tx_conf); @@ -894,25 +894,38 @@ static int s3c24xx_serial_request_dma(struct s3c24xx_uart_port *p) dma->rx_size = PAGE_SIZE; dma->rx_buf = kmalloc(dma->rx_size, GFP_KERNEL); - if (!dma->rx_buf) { - dma_release_channel(dma->rx_chan); - dma_release_channel(dma->tx_chan); - return -ENOMEM; + ret = -ENOMEM; + goto err_release_tx; } dma->rx_addr = dma_map_single(p->port.dev, dma->rx_buf, dma->rx_size, DMA_FROM_DEVICE); - - spin_lock_irqsave(&p->port.lock, flags); + if (dma_mapping_error(p->port.dev, dma->rx_addr)) { + ret = -EIO; + goto err_free_rx; + } /* TX buffer */ dma->tx_addr = dma_map_single(p->port.dev, p->port.state->xmit.buf, UART_XMIT_SIZE, DMA_TO_DEVICE); - - spin_unlock_irqrestore(&p->port.lock, flags); + if (dma_mapping_error(p->port.dev, dma->tx_addr)) { + ret = -EIO; + goto err_unmap_rx; + } return 0; + +err_unmap_rx: + dma_unmap_single(p->port.dev, dma->rx_addr, dma->rx_size, + DMA_FROM_DEVICE); +err_free_rx: + kfree(dma->rx_buf); +err_release_tx: + dma_release_channel(dma->tx_chan); +err_release_rx: + dma_release_channel(dma->rx_chan); + return ret; } static void s3c24xx_serial_release_dma(struct s3c24xx_uart_port *p) -- 1.9.1