From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760353AbcIWTkO (ORCPT ); Fri, 23 Sep 2016 15:40:14 -0400 Received: from mout.kundenserver.de ([212.227.126.135]:50298 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751710AbcIWTkM (ORCPT ); Fri, 23 Sep 2016 15:40:12 -0400 From: Arnd Bergmann To: Greg Kroah-Hartman Cc: Arnd Bergmann , Jiri Slaby , Maxime Coquelin , Alexandre Torgue , Gerald Baeza , linux-serial@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH] serial: stm32: use mapbase instead of membase for DMA Date: Fri, 23 Sep 2016 21:38:51 +0200 Message-Id: <20160923193935.3726427-1-arnd@arndb.de> X-Mailer: git-send-email 2.9.0 X-Provags-ID: V03:K0:3xOxJCCOT+n7OQSBV861/qm6VdZIZMCTY+h/IYTRVsgcF2b2Uxe Y3m3QbkZoayok3W3/aJSysps5xK2FSXpFgZ2AM9RL6gTeXhpqr1/A/maI+qXZm/YPR7TiBW F5N6Y2a2Jg0YQ/eIMjqaWyUWkYSBTnTCk/nB+/aY3haLgMFCBrrLhXC6h0r0RgB4/7GTw64 aMetw5lEWdgi+sND/C5fg== X-UI-Out-Filterresults: notjunk:1;V01:K0:mg/nZhUx1a8=:n7ilXwsIAcTsk4Uj7CJBHZ 7l9vn4RQ4HVp+t6PChFKoJtTJbfzljQNxTblPO9R+kGVQhsdmNTJY12fR41n4ZCs9PyesYHkr DufQRQvaYjvEyKh9tsGrUpL4eGtcncl2dIz8LDfzKKFgk+RrY5kLJm0nKHLikpg8VYMfI4U7b UjOnMSe0J/UW9NOtIL+sNLR/UpoZFypbEGAAfijndi4voGKYifR40JC42PmFGlNdnEcvdgUg8 pRjL4bLsYY1C54jJ1RPNJTDpBytWgDiGSrhuOY8zpHDYOZxf0qek1ecGuKcJ0rMauR6f8bOg5 9kZZ1dLvGD8QFqWHIfvMTWAMmvu4HS8JqfdRlPNFP3Q9uCcL301fg1y2Q4nJPvMz8ZPVWUewi HswB/50XEg+kZzgBH/dOnit4eTM6Exw/0pVa/Tz+j7BUi5LKpyNIBWFkGWF02dbdgOqaFoVa4 nTkJtcvhljWQsTndF57uU4QKQ0IfKhivcd6+fmopZvP5paJxD74KEEkQAvBOST3Mj9H4E382Q rnxKpJoYPxOYpW2q7ZX8G5aMbv7V/XHVYCcoic3ayG4Tn8idu5afZeG4Ftrje2cvcbFoLPQPc i9va+VZNrhKejdJNKrGi+htC4dmCq5wo6qYmG8Vzp7C3MNNk0Ba3JHHWWq6EhQh1CJZpgwEZy Mc15KDZpp2dJVq3EU4n4PSNUff9SsXQ1/wVHbQP8jfPYBCvFFyyLfBksgI0ZJsMIJvYA= Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Building this driver with a 64-bit dma_addr_t type results in a compiler warning: drivers/tty/serial/stm32-usart.c: In function 'stm32_of_dma_rx_probe': drivers/tty/serial/stm32-usart.c:746:20: error: cast from pointer to integer of different size [-Werror=pointer-to-int-cast] drivers/tty/serial/stm32-usart.c: In function 'stm32_of_dma_tx_probe': drivers/tty/serial/stm32-usart.c:818:20: error: cast from pointer to integer of different size [-Werror=pointer-to-int-cast] While the type conversion here is harmless, this hints at a different problem: we pass an __iomem pointer into a DMA engine, which expects a phys_addr_t. This happens to work because stm32 has no MMU and ioremap() is an identity mapping here, but it's still an incorrect API use. Using dma_addr_t is doubly wrong here, because that would be the result of dma_map_single() rather than the physical address. Using the mapbase instead fixes multiple issues: - the warning is gone - we don't go through ioremap in error - the cast is gone, making it use the correct resource_size_t/phys_addr_t type in the process. Fixes: 3489187204eb ("serial: stm32: adding dma support") Signed-off-by: Arnd Bergmann --- drivers/tty/serial/stm32-usart.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c index 4d3001b77e7e..2adb678a863b 100644 --- a/drivers/tty/serial/stm32-usart.c +++ b/drivers/tty/serial/stm32-usart.c @@ -743,7 +743,7 @@ static int stm32_of_dma_rx_probe(struct stm32_port *stm32port, /* Configure DMA channel */ memset(&config, 0, sizeof(config)); - config.src_addr = (dma_addr_t)port->membase + ofs->rdr; + config.src_addr = port->mapbase + ofs->rdr; config.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE; ret = dmaengine_slave_config(stm32port->rx_ch, &config); @@ -815,7 +815,7 @@ static int stm32_of_dma_tx_probe(struct stm32_port *stm32port, /* Configure DMA channel */ memset(&config, 0, sizeof(config)); - config.dst_addr = (dma_addr_t)port->membase + ofs->tdr; + config.dst_addr = port->mapbase + ofs->tdr; config.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE; ret = dmaengine_slave_config(stm32port->tx_ch, &config); -- 2.9.0