On Tue, Mar 14, 2017 at 3:48 PM, Andrey Smirnov
<andrew.smirnov@xxxxxxxxx> wrote:
> Add serdev_device_write() which is a blocking call allowing to transfer
> arbitraty amount of data (potentially exceeding amount that
> serdev_device_write_buf can process in a single call)
> +int serdev_device_write(struct serdev_device *serdev,
> + const unsigned char *buf, size_t count)
> +{
> + int ret = count;
If count by some reason bigger than INT_MAX...
> +
> + if (serdev->ops->write_wakeup)
> + return -EINVAL;
> +
> + mutex_lock(&serdev->write_lock);
> +
> + for (;;) {
> + size_t chunk;
> +
> + reinit_completion(&serdev->write_wakeup);
> +
> + chunk = serdev_device_write_buf(serdev, buf, count);
> + if (chunk < 0) {
This will never happen. What kind of test did you try?
> + ret = chunk;
> + goto done;
> + }
> +
> + buf += chunk;
> + count -= chunk;
> +
> + if (!count)
What is supposed to be returned? Initial count? Does it make any sense?
> + break;
Perhaps you need to refactor this function.
> +
> + wait_for_completion(&serdev->write_wakeup);
> + }
> +done:
It would be nice to have a suffix, like
done_unlock:
But I'm pretty sure if you refactor the code in a smart way you will
not need it.
> + mutex_unlock(&serdev->write_lock);
> + return ret;
> +}
> +EXPORT_SYMBOL_GPL(serdev_device_write);
> /**
> * struct serdev_device - Basic representation of an serdev device
> - * @dev: Driver model representation of the device.
> - * @nr: Device number on serdev bus.
> - * @ctrl: serdev controller managing this device.
> - * @ops: Device operations.
> + * @dev: Driver model representation of the device.
> + * @nr: Device number on serdev bus.
> + * @ctrl: serdev controller managing this device.
> + * @ops: Device operations.
Does it make sense to shift? I would think of shorter field names instead.
> + * @write_wakeup Completion used by serdev_device_write internally
Colon is missed.
Another filed is missed.
> */
> struct serdev_device {
> struct device dev;
> int nr;
> struct serdev_controller *ctrl;
> const struct serdev_device_ops *ops;
> + struct completion write_wakeup;
> + struct mutex write_lock;
> };
>
> static inline struct serdev_device *to_serdev_device(struct device *d)
> @@ -162,10 +165,13 @@ static inline void serdev_controller_write_wakeup(struct serdev_controller *ctrl
> {
> struct serdev_device *serdev = ctrl->serdev;
>
> - if (!serdev || !serdev->ops->write_wakeup)
> + if (!serdev)
> return;
>
> - serdev->ops->write_wakeup(serdev);
> + if (serdev->ops->write_wakeup)
> + serdev->ops->write_wakeup(serdev);
> + else
> + complete(&serdev->write_wakeup);
By the way does this changes the possible context of application
(atomic / non-atomic)?
--
With Best Regards,
Andy Shevchenko
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