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From: Greg KH <greg@kroah.com>
To: Albrecht Dre? <albrecht.dress@arcor.de>
Cc: linux-serial@vger.kernel.org
Subject: Re: [PPC/MPC5200B] strange data loss on uart reception
Date: Sun, 31 Oct 2010 20:10:03 -0700	[thread overview]
Message-ID: <20101101031003.GA2903@kroah.com> (raw)
In-Reply-To: <1288546021.1866.1@antares>

On Sun, Oct 31, 2010 at 06:27:00PM +0100, Albrecht Dre? wrote:
 Am I simply too dumb to use the uart correctly, or is there some issue
> in the kernel causing this effect?  I noticed that the function
> mpc52xx_uart_int_rx_chars() does not check the return value of
> tty_insert_flip_char().  If the system runs out of space (actually,
> the maximum buffer size used should be limited, in particular on
> embedded systems!), might this go undetected?  This might explain the
> bigger "chunks", as the '5200's uart has a rather big fifo (512
> bytes).

That might help, have you tried changing this and seeing if it fixes
anything?

Also, are you sure your userspace application is checking the return
value of write() to verify that it really wrote everything it thought it
did?

thanks,

greg k-h

  reply	other threads:[~2010-11-01  3:10 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-10-31 17:27 [PPC/MPC5200B] strange data loss on uart reception Albrecht Dreß
2010-11-01  3:10 ` Greg KH [this message]
2010-11-01 14:41   ` Albrecht Dreß
2010-11-02 18:06     ` Albrecht Dreß
2010-11-03  4:02       ` Greg KH

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