Messages in this thread | | | Date | Wed, 25 Nov 2015 22:26:12 +0200 | Subject | Re: [PATCH v2] USB: serial: cp210x: Add tx_empty() | From | Andy Shevchenko <> |
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On Wed, Nov 25, 2015 at 12:28 AM, Konstantin Shkolnyy <konstantin.shkolnyy@gmail.com> wrote: > Added tx_empty callback needed for generic wait-until-sent support. > Without this function, when the port is closed usbserial can't know that > there are still data in the chip's transmit FIFO. The chip gets disabled > and untransmitted data lost. When the actual byte count is reported by > tx-empty the close can be delayed until all data are sent. >
> /* > + * Read how many bytes are waiting in the TX queue. > + */
One line?
> +static bool cp210x_tx_empty(struct usb_serial_port *port) > +{ > + int err; > + u32 count; > + > + err = cp210x_get_tx_queue_byte_count(port, &count);
> + if (!err && count) > + return false; > + > + return true;
return err || !count;
Btw, can be count left uninitialized?
-- With Best Regards, Andy Shevchenko
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