Messages in this thread | | | From | Rob Herring <> | Date | Fri, 24 Mar 2017 13:31:19 -0500 | Subject | Re: [PATCH] serdev: Replace serdev_device_write_buf with serdev_device_write |
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On Mon, Mar 20, 2017 at 11:56 AM, Andrey Smirnov <andrew.smirnov@gmail.com> wrote: > Convert serdev_device_write_buf's code to be able to transfer amount of > data potentially exceeding "write room" at the moment of invocation. > > To support that, also add serdev_device_write_wakeup. > > Drivers wanting to use full extent of serdev_device_write functionality > asre 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. > > Drivers wanting to retain old serdev_device_write_buf behaviour can > replace those call to calls to serdev_device_write with timeout of > 0. Providing .write_wakeup handler in such case is optional.
Looks good, just a couple of things.
> > 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> > --- > drivers/tty/serdev/core.c | 36 +++++++++++++++++++++++++++++++----- > include/linux/serdev.h | 11 +++++++++-- > 2 files changed, 40 insertions(+), 7 deletions(-) > > diff --git a/drivers/tty/serdev/core.c b/drivers/tty/serdev/core.c > index f4c6c90..9962d84 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 && > + wait_for_completion_timeout(&serdev->write_comp, > + timeout));
This is going to wait for timeout time on each loop. We want the timeout passed in to be the total time.
> + mutex_unlock(&serdev->write_lock); > + return ret < 0 ? ret : (count ? -ETIMEDOUT : 0); > } > -EXPORT_SYMBOL_GPL(serdev_device_write_buf); > +EXPORT_SYMBOL_GPL(serdev_device_write); > > void serdev_device_write_flush(struct serdev_device *serdev) > { > @@ -232,6 +256,8 @@ struct serdev_device *serdev_device_alloc(struct serdev_controller *ctrl) > serdev->dev.parent = &ctrl->dev; > serdev->dev.bus = &serdev_bus_type; > serdev->dev.type = &serdev_device_type; > + init_completion(&serdev->write_comp); > + mutex_init(&serdev->write_lock); > return serdev; > } > EXPORT_SYMBOL_GPL(serdev_device_alloc); > diff --git a/include/linux/serdev.h b/include/linux/serdev.h > index 5176cdc..18cbbed 100644 > --- a/include/linux/serdev.h > +++ b/include/linux/serdev.h > @@ -39,12 +39,17 @@ struct serdev_device_ops { > * @nr: Device number on serdev bus. > * @ctrl: serdev controller managing this device. > * @ops: Device operations. > + * @write_comp Completion used by serdev_device_write internally > + * @write_lock Mutext used to esure exclusive access to the bus when > + * writing data with serdev_device_write() > */ > struct serdev_device { > struct device dev; > int nr; > struct serdev_controller *ctrl; > const struct serdev_device_ops *ops; > + struct completion write_comp; > + struct mutex write_lock; > }; > > static inline struct serdev_device *to_serdev_device(struct device *d) > @@ -186,10 +191,12 @@ int serdev_device_open(struct serdev_device *); > void serdev_device_close(struct serdev_device *); > unsigned int serdev_device_set_baudrate(struct serdev_device *, unsigned int); > void serdev_device_set_flow_control(struct serdev_device *, bool); > -int serdev_device_write_buf(struct serdev_device *, const unsigned char *, size_t); > +void serdev_device_write_wakeup(struct serdev_device *); > +int serdev_device_write(struct serdev_device *, const unsigned char *, size_t, unsigned long); > void serdev_device_write_flush(struct serdev_device *); > int serdev_device_write_room(struct serdev_device *); > > + > /* > * serdev device driver functions > */ > @@ -223,7 +230,7 @@ static inline unsigned int serdev_device_set_baudrate(struct serdev_device *sdev > return 0; > } > static inline void serdev_device_set_flow_control(struct serdev_device *sdev, bool enable) {} > -static inline int serdev_device_write_buf(struct serdev_device *sdev, const unsigned char *buf, size_t count)
We probably should keep a wrapper for serdev_device_write_buf to avoid cross tree dependencies. However, the Nokia BT support is going to have them anyway.
> +static inline int serdev_device_write(struct serdev_device *sdev, const unsigned char *buf, size_t count) > { > return -ENODEV; > } > -- > 2.9.3 >
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