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From: Chen Gang <gang.chen@asianux.com>
To: Paul Fulghum <paulkf@microgate.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>,
	Greg KH <gregkh@linuxfoundation.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	linux-serial@vger.kernel.org
Subject: Re: [PATCH] synclink fix ldisc buffer argument
Date: Mon, 03 Dec 2012 10:20:52 +0800	[thread overview]
Message-ID: <50BC0C84.4060802@asianux.com> (raw)
In-Reply-To: <989CB961-79F8-479B-B16C-41358A60AC94@microgate.com>

于 2012年12月03日 04:05, Paul Fulghum 写道:
> OK, I’ll do that.
> 

pardon (I am just learning)
  does 65535 mean HDLC_MAX_FRAME_SIZE ?
  why do we need info->max_frame_size >= 4096 ?

in drivers/tty/synclink_gt.c:
3550         if (info->max_frame_size < 4096)
3551                 info->max_frame_size = 4096;
3552         else if (info->max_frame_size > 65535)
3553                 info->max_frame_size = 65535;
3554
 ...
3603                 info->max_frame_size = 4096;


if possible:
  can we move the relative comments (which are inside function) to the
location just above ldisc_receive_buf ?


  thanks.

gchen.


> On Dec 2, 2012, at 12:10 PM, Alan Cox <alan@lxorguk.ukuu.org.uk
> <mailto:alan@lxorguk.ukuu.org.uk>> wrote:
> 
>> On Sun, 2 Dec 2012 10:11:58 -0600
>> Paul Fulghum <paulkf@microgate.com <mailto:paulkf@microgate.com>> wrote:
>>
>>> True, in this mode line disciplines other than N_HDLC would not be
>>> functional and N_HDLC ignores the flag buffer.
>>> This change won’t make other line disciplines useful, it will just
>>> prevent the case of a mistakenly selected line discipline accessing
>>> beyond the end of the (dummy) flag buffer.
>>>
>>> I’m fine with or without the change. It is functional now with a
>>> chance to read past then end of a buffer if misconfigured. With the
>>> change, it has the same functionality without the ability to read
>>> past the end of a buffer if misconfigured.
>>
>> With the change its feeding crap in the flags buffer, which may matter in
>> future depending what happens to the other bits.
>>
>> If this is a real issue far better to just kzalloc a blank flag buffer to
>> match the mtu.
>>
> 
> -- 
> Paul Fulghum
> MicroGate Systems, Ltd.
> =Customer Driven, by Design=
> (800)444-1982
> (512)345-7791 (Direct)
> (512)343-9046 (Fax)
> Central Time Zone (GMT -5h)
> www.microgate.com <http://www.microgate.com/>
> 


-- 
Chen Gang

Asianux Corporation

  parent reply	other threads:[~2012-12-03  2:20 UTC|newest]

Thread overview: 29+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <50B6E751.9000000@asianux.com>
2012-11-29  5:07 ` [Suggestion] drivers/tty: drivers/char/: for MAX_ASYNC_BUFFER_SIZE Chen Gang
2012-11-29 13:41   ` Alan Cox
2012-11-30  2:27     ` Chen Gang
2012-11-30  3:39       ` Chen Gang
2012-11-29  5:13 ` 【Suggestion】drivers/tty: " Greg KH
2012-11-29  5:57   ` [Suggestion] drivers/tty: " Chen Gang
2012-11-29  6:14     ` [PATCH] MAINTAINERS: TTY - Add linux-serial mailing list Joe Perches
2012-11-29  6:27       ` Chen Gang
2012-11-29  8:23       ` Jiri Slaby
2012-11-29 18:32     ` [Suggestion] drivers/tty: drivers/char/: for MAX_ASYNC_BUFFER_SIZE Greg KH
2012-11-30  2:52       ` Chen Gang
     [not found]         ` <C7D3911F-7B6B-4353-A84B-0218FAB27198@microgate.com>
2012-11-30  6:28           ` Chen Gang
2012-11-30  7:14           ` Chen Gang
2012-11-30 16:24         ` Paul Fulghum
2012-11-30 19:46           ` [PATCH] synclink fix ldisc buffer argument Paul Fulghum
2012-12-02 15:13             ` Alan Cox
     [not found]               ` <F6B8A325-7DBF-4623-B16C-CDC5642EFD16@microgate.com>
2012-12-02 18:10                 ` Alan Cox
     [not found]                   ` <989CB961-79F8-479B-B16C-41358A60AC94@microgate.com>
2012-12-03  2:20                     ` Chen Gang [this message]
2012-12-03 16:03                       ` Paul Fulghum
2012-12-05  1:57                         ` Chen Gang
2012-12-19  2:23                           ` Chen Gang
2012-12-19  4:09                             ` Greg KH
2012-12-19  4:10                               ` Chen Gang
2012-12-20  4:16                               ` [PATCH] drivers/tty/synclink: let receive buffer size match max frame size Chen Gang
2012-12-03 17:13             ` [PATCH] synclink fix ldisc buffer argument Paul Fulghum
2012-12-05  1:35               ` Chen Gang
2012-12-07  2:15               ` Chen Gang
2012-12-10  1:32                 ` [Consult]: " Chen Gang
2012-12-01  9:01           ` [Suggestion] drivers/tty: drivers/char/: for MAX_ASYNC_BUFFER_SIZE Chen Gang

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