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

Peter Hurley
2015-11-13T01:11:20Z

On 11/12/2015 07:41 PM, Andy Shevchenko wrote:
> On Thu, Nov 12, 2015 at 10:22 PM, Peter Hurley <peter@hurleysoftware.com> wrote:
>> On 11/12/2015 02:57 PM, One Thousand Gnomes wrote:
>
>> An illustrative (kernel-space) example is the mess that is dmaengine_pause().
>> Some DMA implementations provide the means to stop and restart DMA without
>> losing data and some DMA implementations do not. Unfortunately, some
>> advertise they support dmaengine_pause() but only for lossy uses like audio.
>> Because the api hides this, the query interface for pause support is
>> useless.
>
> The DMA pause() call means only pause with possibility to resume.
> There is a resume() call as well. Any driver which treats pause() as a
> complete stop is buggy driver and should be fixed.

How about pause _without_ the possibility to resume?