The original DMA support works only when RTS/CTS is enabled. (see the "e800163 serial: mxs-auart: add the DMA support for mx28") But after several patches, DMA support has lost this limit. (see the "bcc20f9 serial: mxs-auart: move to use generic DMA helper") So a UART without the RTS/CTS lines may also enables the DMA support for it, but it may does not work or works abnormally (since without the RTS/CTS signals, the TX/RX may not works) This patch set remove the unnecessary macro MXS_AUART_DMA_CONFIG, and adds an optional property "fsl,uart-has-rtscts" for the UART DT node which indicates the UART has RTS and CTS lines. This patch set also adds a macro MXS_AUART_RTSCTS, and uses it to check RTS/CTS before we enable the DMA for the UART. At last, enable the DMA support for auart0 in the imx28-evk boards. v2 --> v3: [0] make the patch 2 as the first patch. [1] add more comments. v1 --> v2: [0] changed the comments. [1] fix the typos. Huang Shijie (3): serial: mxs: enable the DMA only when the RTS/CTS is valid serial: mxs: remove the MXS_AUART_DMA_CONFIG ARM: dts: imx28-evk: add the RTS/CTS property for auart0 .../bindings/tty/serial/fsl-mxs-auart.txt | 4 ++++ arch/arm/boot/dts/imx28-evk.dts | 1 + drivers/tty/serial/mxs-auart.c | 8 +++++--- 3 files changed, 10 insertions(+), 3 deletions(-) -- 1.7.4.4 -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
