Message-ID: <47BDD26D.5010004@davidnewall.com>
Date: Fri, 22 Feb 2008 06:05:09 +1030
From: David Newall <davidn@davidnewall.com>
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To: Alan Cox <alan@lxorguk.ukuu.org.uk>
CC: Greg KH <greg@kroah.com>, linux-usb@vger.kernel.org,
       Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: Handshaking on USB serial devices
References: <47B30291.2040905@davidnewall.com>	<20080214050211.GB1432@kroah.com>	<47B40918.20206@davidnewall.com>	<20080214121026.16a9c510@core>	<47B482B4.9010208@davidnewall.com>	<20080214193637.5df1c205@core>	<47BD9721.70907@davidnewall.com> <20080221151549.0fa72422@core>
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Alan Cox wrote:
>> developing is entirely wrong.  Oh well.  Mind you, providing a
>> write_room function is NOT a real solution; it merely reduces the
>> condition to a usually-winnable race.  (Ironically, when I back-ported
>> the 2.6 driver, I excluded its new write_room function.  Mistake.)
>>     
>
> What race do you see left ?
>   

On second thoughts I'm not sure that I do.  I've had my head so full of
2.4 pl2303, and 2.4 pl2303 with this, that and the other added to it,
that I was probably just confused.  Certainly it's not important,
because I didn't mean the 2.6 driver, but an hypothetical 2.4 with a
simplistic write_room function added (e.g. return
port->write_urb->status == -EINPROGRESS ? 0 : 64).  OPOST processing's
use of putchar to expand CRLF sends two writes (or putchars), with no
intervening checks.  Since I'm just polishing off my back-port of
2.6.24.1 pl2303 to kernel 2.4, the matter is quite irrelevant.

By the way, what happened to HUawei E620 UMTS/HSDPA card?  It's in
pl2303 in 2.6.23; not in 2.6.24.1.  (Do I remove it from my back-port?)
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