From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Tomoya MORINAGA <tomoya.rohm@gmail.com>
Cc: Alan Cox <alan@linux.intel.com>,
linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org,
qi.wang@intel.com, yong.y.wang@intel.com, joel.clark@intel.com,
kok.howg.ewe@intel.com
Subject: Re: [PATCH] pch_uart: Fix dma channel unallocated issue
Date: Mon, 9 Apr 2012 10:44:05 -0700 [thread overview]
Message-ID: <20120409174405.GA25990@kroah.com> (raw)
In-Reply-To: <1332842162-26113-1-git-send-email-tomoya.rohm@gmail.com>
On Tue, Mar 27, 2012 at 06:56:02PM +0900, Tomoya MORINAGA wrote:
> This driver anticipates pch_uart_verify_port() is not called
> during installation.
> However, actually pch_uart_verify_port() is called during
> installation.
> As a result, memory access violation occurs like below.
>
> 0. initial value: use_dma=0
> 1. starup()
> - dma channel is not allocated because use_dma=0
> 2. pch_uart_verify_port()
> - Set use_dma=1
> 3. UART processing acts DMA mode because use_dma=1
> - memory access violation occurs!
>
> This patch fixes the issue.
>
> Solution:
> Whenever pch_uart_verify_port() is called and then
> dma channel is not allocated, the channel should be allocated.
>
> Signed-off-by: Tomoya MORINAGA <tomoya.rohm@gmail.com>
> ---
> drivers/tty/serial/pch_uart.c | 4 +++-
> 1 files changed, 3 insertions(+), 1 deletions(-)
This patch does not apply to 3.4-rc2, so I can not apply it, sorry.
Care to redo it?
greg k-h
next prev parent reply other threads:[~2012-04-09 17:44 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-03-27 9:56 [PATCH] pch_uart: Fix dma channel unallocated issue Tomoya MORINAGA
2012-04-09 17:44 ` Greg Kroah-Hartman [this message]
2012-04-10 1:26 ` Tomoya MORINAGA
2012-04-10 14:41 ` Greg Kroah-Hartman
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