Hi Greg, et. al. This series aims to keep 8250 dma and the omap8250 variant from diverging further, in the hopes that at some point the implementations will converge. The first 2 patches add an overlooked requirement of using the dmaengine interface; namely ensuring the actual dmaengine driver is capable of the operations required by the 8250 client. The 8250 driver requires the dmaengine driver to support dma pause with terminate for the rx channel, and further requires better-than- descriptor residue accuracy (so that it is possible for dma to be paused without completing followed by pio read of remaining rx data _without losing data_. Note however that the dmaengine driver query is known to be insufficient, as at least one driver (omap-dma) does not support the requirements for this use case but reports that it does. My hope is to extend slave caps reporting to allow dmaengine clients to distinguish incomplete pause/resume support. A similar check is added for the tx chanenl. Soon I expect to add pause check to tx channel as well, as I believe it will be required to implement XON/XOFF transmit *which is completely missing* - with dma enabled the x_char is never transmitted. The remaining patches cleanup the rx dma interface; the rx dma flush is extracted as a separate operation, rather than as a sub-operation of dma flow. REQUIRES: 4-patch series "serial: 8250: misc cleanups" Regards, Peter Hurley (6): serial: 8250: Validate dmaengine rx chan meets requirements serial: 8250: Validate dmaengine tx chan meets requirements serial: omap8250: Drop rx buffer sync serial: omap8250: Simplify rx dma completion interface serial: 8250: Extract IIR logic steering from rx dma serial: omap8250: Terminate rx dma only for flushes drivers/tty/serial/8250/8250.h | 8 ++-- drivers/tty/serial/8250/8250_dma.c | 68 ++++++++++++++++++------------ drivers/tty/serial/8250/8250_omap.c | 83 ++++++++++++++----------------------- drivers/tty/serial/8250/8250_port.c | 14 ++++++- 4 files changed, 92 insertions(+), 81 deletions(-) -- 2.8.1 -- 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
