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From: Rob Herring <robh@kernel.org>
Date: Fri, 26 Aug 2016 16:27:35 -0500
Message-ID: <CAL_JsqLNeV9BDvRtRbDCKbrq-gO9jv8-kmGJNS9AKXUSmEvYOA@mail.gmail.com>
Subject: Re: [RFC PATCH 4/6] serio: serport: add support for buffered write
 and receive
To: Pavel Machek <pavel@ucw.cz>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>, Marcel Holtmann <marcel@holtmann.org>,
	Jiri Slaby <jslaby@suse.com>, Sebastian Reichel <sre@kernel.org>, Arnd Bergmann <arnd@arndb.de>,
	"Dr . H . Nikolaus Schaller" <hns@goldelico.com>, Alan Cox <gnomes@lxorguk.ukuu.org.uk>,
	Loic Poulain <loic.poulain@intel.com>, Peter Hurley <peter@hurleysoftware.com>,
	NeilBrown <neil@brown.name>, Linus Walleij <linus.walleij@linaro.org>,
	"open list:BLUETOOTH DRIVERS" <linux-bluetooth@vger.kernel.org>,
	"linux-serial@vger.kernel.org" <linux-serial@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
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List-ID: <linux-bluetooth.vger.kernel.org>

On Fri, Aug 26, 2016 at 3:12 PM, Pavel Machek <pavel@ucw.cz> wrote:
> Hi!
>
>> @@ -133,26 +133,29 @@ static void serport_ldisc_receive(struct tty_struct *tty, const unsigned char *c
>>       if (!test_bit(SERPORT_ACTIVE, &serport->flags))
>>               goto out;
>>
>> -     for (i = 0; i < count; i++) {
>> -             if (fp) {
>> -                     switch (fp[i]) {
>> -                     case TTY_FRAME:
>> -                             ch_flags = SERIO_FRAME;
>> -                             break;
>> -
>> -                     case TTY_PARITY:
>> -                             ch_flags = SERIO_PARITY;
>> -                             break;
>> -
>> -                     default:
>> -                             ch_flags = 0;
>> -                             break;
>> +     if (serio_buffered_mode_enabled(serport->serio)) {
>> +             serio_receive_buf(serport->serio, cp, count);
>
> Elsewhere:
> +       /* Use buffer receive if the driver provides a callback */
> +       if (drv->receive_buf)
> +               set_bit(SERIO_MODE_BUFFERED, &drv->flags);
>
> Could we use if (drv->receive_buf) above directly, and not require the
> bitfield?

I'm allowing for allowing drivers to provide both functions and be
able to switch between them. However, I didn't provide any mechanism
to do so yet.

Rob