Re: [PATCH v3 2/5] tty: Introduce SER_RS485_SOFTWARE read-only flag for struct serial_rs485

Peter Hurley
2015-12-03T14:41:28Z

Hi Matwey,

On 12/03/2015 12:50 AM, Matwey V. Kornilov wrote:
> I am working on v4, where I completely redesigned implementation. And
> now I think that it is considerably better than v3.
> It looks like the following:
> https://github.com/matwey/linux/commits/8520_rs485_v4
> But it is not ready yet, there is a bug somewhere.
>
> In the v4, each subdriver decides separately if it needs rs485
> emulation support. Then it enables it like the following:
> https://github.com/matwey/linux/commit/4455e425fc045713fb921ccec695fe183f1558f0
> Before calling serial8250_rs485_emul_enabled, the driver enables
> interrupt on empty shift register (they are always there for omap_).

Looks good.

Are you testing with CONFIG_SERIAL_8250_DMA=n first to simplify the
debug effort? DMA adds a completely different tx path.

Also, before submission, please shorten the identifiers. And Greg hates
functions returning bool so just expanded serial8250_rs485_emul_enabled()
inline.

Regards,
Peter Hurley