On Tue, 17 Aug 2010 09:37:34 +0800
Yong Wang [off-list ref] wrote:

Hi all,

We have a PCI based UART controller that is compatible with the
existing 8250 serial driver in most aspects. However, one exception
is that our UART controller can take advantage of the onboard DMA
contoller to achieve higher throughput. Could you please share your
insights about what is the proper way to add such DMA support into
existing 8250 driver?

I'd say the same as I said to the other folks who asked this - create a
new driver. All the DMA based 8250 devices have differing DMA engines
and it'll become unmanagable in the existing driver.

Once we can see which bits of the existing code are useful for the DMA
8250-style devices we can then create an 8250-lib.c which contains the
bits that are useful to 8250 and to non standard 8250-like devices.

Alan