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

From	Andy Shevchenko <andy.shevchenko@gmail.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH v3 2/5] tty: Introduce SER_RS485_SOFTWARE read-only flag for struct serial_rs485
Date	2015-11-13 01:50 +0100
Message-ID	<quaIX-7Mk-35@gated-at.bofh.it> (permalink)
References	<qu1cC-1EX-7@gated-at.bofh.it> <qu1cC-1EX-5@gated-at.bofh.it> <qu6Fk-5dX-13@gated-at.bofh.it> <qu6Fk-5dX-11@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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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.

-- 
With Best Regards,
Andy Shevchenko
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Thread

[PATCH v3 2/5] tty: Introduce SER_RS485_SOFTWARE read-only flag for struct serial_rs485 "Matwey V. Kornilov" <matwey@sai.msu.ru> - 2015-11-12 15:40 +0100
  Re: [PATCH v3 2/5] tty: Introduce SER_RS485_SOFTWARE read-only flag  for struct serial_rs485 Peter Hurley <peter@hurleysoftware.com> - 2015-11-12 21:30 +0100
    Re: [PATCH v3 2/5] tty: Introduce SER_RS485_SOFTWARE read-only flag  for struct serial_rs485 Andy Shevchenko <andy.shevchenko@gmail.com> - 2015-11-13 01:50 +0100
      Re: [PATCH v3 2/5] tty: Introduce SER_RS485_SOFTWARE read-only flag  for struct serial_rs485 Peter Hurley <peter@hurleysoftware.com> - 2015-11-13 02:20 +0100
        Re: [PATCH v3 2/5] tty: Introduce SER_RS485_SOFTWARE read-only flag  for struct serial_rs485 Andy Shevchenko <andy.shevchenko@gmail.com> - 2015-11-13 02:30 +0100
          Re: [PATCH v3 2/5] tty: Introduce SER_RS485_SOFTWARE read-only flag  for struct serial_rs485 Peter Hurley <peter@hurleysoftware.com> - 2015-11-13 03:00 +0100
    Re: [PATCH v3 2/5] tty: Introduce SER_RS485_SOFTWARE read-only flag  for struct serial_rs485 One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk> - 2015-11-14 16:30 +0100
  Re: [PATCH v3 2/5] tty: Introduce SER_RS485_SOFTWARE read-only flag  for struct serial_rs485 One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk> - 2015-11-12 21:50 +0100
    Re: [PATCH v3 2/5] tty: Introduce SER_RS485_SOFTWARE read-only flag  for struct serial_rs485 "Matwey V. Kornilov" <matwey@sai.msu.ru> - 2015-11-13 21:10 +0100

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