From mboxrd@z Thu Jan 1 00:00:00 1970 From: Greg Kroah-Hartman Subject: Re: [PATCH] pch_uart: Fix dma channel unallocated issue Date: Mon, 9 Apr 2012 10:44:05 -0700 Message-ID: <20120409174405.GA25990@kroah.com> References: <1332842162-26113-1-git-send-email-tomoya.rohm@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <1332842162-26113-1-git-send-email-tomoya.rohm@gmail.com> Sender: linux-kernel-owner@vger.kernel.org To: Tomoya MORINAGA Cc: Alan Cox , 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 List-Id: linux-serial@vger.kernel.org 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 > --- > 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