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: Tue, 10 Apr 2012 07:41:10 -0700 Message-ID: <20120410144110.GE14703@kroah.com> References: <1332842162-26113-1-git-send-email-tomoya.rohm@gmail.com> <20120409174405.GA25990@kroah.com> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from mail-pz0-f52.google.com ([209.85.210.52]:44657 "EHLO mail-pz0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755514Ab2DJOlP (ORCPT ); Tue, 10 Apr 2012 10:41:15 -0400 Received: by dake40 with SMTP id e40so6732310dak.11 for ; Tue, 10 Apr 2012 07:41:14 -0700 (PDT) Content-Disposition: inline In-Reply-To: Sender: linux-serial-owner@vger.kernel.org List-Id: linux-serial@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 On Tue, Apr 10, 2012 at 10:26:25AM +0900, Tomoya MORINAGA wrote: > On Tue, Apr 10, 2012 at 2:44 AM, Greg Kroah-Hartman > 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=3D0 > >> 1. starup() > >> =A0 =A0 - dma channel is not allocated because use_dma=3D0 > >> 2. pch_uart_verify_port() > >> =A0 =A0 - Set use_dma=3D1 > >> 3. UART processing acts DMA mode because use_dma=3D1 > >> =A0 =A0 =A0- 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 > >> --- > >> =A0drivers/tty/serial/pch_uart.c | =A0 =A04 +++- > >> =A01 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? >=20 > This patch depends on the following patch you've already accepted. >=20 > >From 44db113212d86a5870c2bfe8fb767fa842d68805 Mon Sep 17 00:00:00 20= 01 > From: Tomoya MORINAGA > Date: Mon, 26 Mar 2012 14:43:00 +0900 > Subject: pch_uart: Delete unused structure member >=20 > Signed-off-by: Tomoya MORINAGA > Signed-off-by: Greg Kroah-Hartman > --- > drivers/tty/serial/pch_uart.c | 2 -- > 1 file changed, 2 deletions(-) >=20 >=20 > So now, this patch can be applied. > In fact, I've confirmed this patch can be applied to 3.4-rc2 with the > following order. > 1st: pch_uart: Delete unused structure member That patch is not applicable for the 3.4-release. > 2nd: pch_uart: Fix dma channel unallocated issue But I thought this one would be, which is why I did not try to apply anything else before it. > I should have written the dependency. Yes, you always should. > Could you try to apply this patch again ? Don't you want this patch in the 3.4-final release? If so, I need it without the dependancy. thanks, greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-serial"= in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html