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authorArnd Bergmann <arnd@arndb.de>2016-09-23 22:38:51 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2016-09-27 13:54:03 +0300
commit8e5481d98bbf1de0ff06a3e488b668572d578e61 (patch)
tree37d9d82ee20a28f6d4cc820a4532a1184f61577d /drivers/tty
parent36131cdfef5aef7f4a9a36423a7a338bd6f68ad6 (diff)
downloadlinux-8e5481d98bbf1de0ff06a3e488b668572d578e61.tar.xz
serial: stm32: use mapbase instead of membase for DMA
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 <arnd@arndb.de> Reviewed-by: Gerald Baeza <gerald.baeza@st.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty')
-rw-r--r--drivers/tty/serial/stm32-usart.c4
1 files 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);