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From: Toby Gray <toby.gray@realvnc.com>
To: stefan.bigler@keymile.com
Cc: balbi@ti.com, Alan Cox <alan@lxorguk.ukuu.org.uk>,
	Greg KH <greg@kroah.com>,
	linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org
Subject: Re: TTY loosing data with u_serial gadget
Date: Thu, 24 Mar 2011 16:15:02 +0000	[thread overview]
Message-ID: <4D8B6E06.2060506@realvnc.com> (raw)
In-Reply-To: <4D8B65F4.40306@keymile.com>

On 24/03/2011 15:40, Stefan Bigler wrote:
> Can you try this:
>> diff --git a/drivers/tty/tty_buffer.c b/drivers/tty/tty_buffer.c
>> index 2f119e2..f0b9fb6 100644
>> --- a/drivers/tty/tty_buffer.c
>> +++ b/drivers/tty/tty_buffer.c
>
> I tried it and the console is working again.
> There is still an problem on heavy load transfer from host to gadget.
> I attached the patch to fix also this problem.
>
> diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c
> index 8e0f113..95d0a9c 100644
> --- a/drivers/tty/n_tty.c
> +++ b/drivers/tty/n_tty.c
> @@ -1359,6 +1359,7 @@ static unsigned int n_tty_receive_buf(struct 
> tty_struct *tty,
>                 memcpy(tty->read_buf + tty->read_head, cp, i);
>                 tty->read_head = (tty->read_head + i) & 
> (N_TTY_BUF_SIZE-1);
>                 tty->read_cnt += i;
> +               ret += i;
>                 spin_unlock_irqrestore(&tty->read_lock, cpuflags);
>         } else {
>                 ret = count;
>
> With this patch I was able to transfer gigabytes without lost data.

I can confirm that this combined with the last two patches from Felipe 
Balbi fix all the issues I've had as well and seems stable and without 
loss under fast data transfers.

Regards,

Toby


  reply	other threads:[~2011-03-24 16:15 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-03-16 20:47 TTY loosing data with u_serial gadget Stefan Bigler
2011-03-17  0:04 ` Greg KH
2011-03-18 16:35   ` Stefan Bigler
2011-03-18 17:08     ` Felipe Balbi
2011-03-18 18:06       ` Alan Cox
2011-03-21  9:32         ` Felipe Balbi
2011-03-22  8:53           ` Felipe Balbi
2011-03-22 11:04             ` Alan Cox
2011-03-22 17:01               ` Greg KH
2011-03-24 12:07             ` Toby Gray
2011-03-24 12:37               ` Felipe Balbi
2011-03-24 12:51                 ` Toby Gray
2011-03-24 13:00                   ` Felipe Balbi
2011-03-24 15:40                     ` Stefan Bigler
2011-03-24 16:15                       ` Toby Gray [this message]
2011-03-25 11:02                         ` Felipe Balbi
2011-03-18 21:46       ` Stefan Bigler
2011-03-18 18:07     ` Alan Cox
2011-03-18 21:15       ` Stefan Bigler

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