lkml.org 
[lkml]   [2017]   [Mar]   [31]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: [PATCH v3] serdev: Add serdev_device_write subroutine
On Thu, Mar 30, 2017 at 5:00 PM, Andrey Smirnov
<andrew.smirnov@gmail.com> wrote:
> Add serdev_device_write() a blocking call allowing to transfer
> arbitraty amount of data (potentially exceeding amount that
> serdev_device_write_buf can process in a single call)
>
> To support that, also add serdev_device_write_wakeup().
>
> Drivers wanting to use full extent of serdev_device_write
> functionality are expected to provide serdev_device_write_wakeup() as
> a sole handler of .write_wakeup event or call it as a part of driver's
> custom .write_wakeup code.
>
> Because serdev_device_write() subroutine is a superset of
> serdev_device_write_buf() the patch re-impelements latter is terms of
> the former. For drivers watning to just use serdev_device_write_buf()

typo

> .write_wakeup handler is optional.
>
> Cc: cphealy@gmail.com
> Cc: Guenter Roeck <linux@roeck-us.net>
> Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
> Cc: linux-serial@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
> ---
>
> Changes since v2 (see [v2]):
>
> - Changed subject and commit message wording to better reflect
> nature of the patch
>
> - Various spelling, formatting, documentation and wording
> fixes as caught/suggested by Andy
>
> Changes since v1 (see [v1]):
>
> - Make timeout to be a total(as opposed to per-iteration)
> timeout
>
> - Keep serdev_device_write_buf() as a wrapper arount
> serdev_device_write() for compatibility
>
> [v2] https://lkml.org/lkml/2017/3/28/942
> [v1] https://lkml.org/lkml/2017/3/20/650
>
> drivers/tty/serdev/core.c | 36 +++++++++++++++++++++++++++++++-----
> include/linux/serdev.h | 17 +++++++++++++++--
> 2 files changed, 46 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/tty/serdev/core.c b/drivers/tty/serdev/core.c
> index f4c6c90..6701d10 100644
> --- a/drivers/tty/serdev/core.c
> +++ b/drivers/tty/serdev/core.c
> @@ -116,17 +116,41 @@ void serdev_device_close(struct serdev_device *serdev)
> }
> EXPORT_SYMBOL_GPL(serdev_device_close);
>
> -int serdev_device_write_buf(struct serdev_device *serdev,
> - const unsigned char *buf, size_t count)
> +void serdev_device_write_wakeup(struct serdev_device *serdev)
> +{
> + complete(&serdev->write_comp);
> +}
> +EXPORT_SYMBOL_GPL(serdev_device_write_wakeup);
> +
> +int serdev_device_write(struct serdev_device *serdev,
> + const unsigned char *buf, size_t count,
> + unsigned long timeout)
> {
> struct serdev_controller *ctrl = serdev->ctrl;
> + int ret;
>
> - if (!ctrl || !ctrl->ops->write_buf)
> + if (!ctrl || !ctrl->ops->write_buf ||
> + (timeout && !serdev->ops->write_wakeup))
> return -EINVAL;
>
> - return ctrl->ops->write_buf(ctrl, buf, count);
> + mutex_lock(&serdev->write_lock);
> + do {
> + reinit_completion(&serdev->write_comp);
> +
> + ret = ctrl->ops->write_buf(ctrl, buf, count);
> + if (ret < 0)
> + break;
> +
> + buf += ret;
> + count -= ret;
> +
> + } while (count &&
> + (timeout = wait_for_completion_timeout(&serdev->write_comp,
> + timeout)));

Need to test for timeout < 0 here and return timeout when < 0.

Rob

\
 
 \ /
  Last update: 2017-03-31 15:25    [W:0.087 / U:0.356 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site