From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marc Zyngier Subject: Re: earlycon issues in -next with amba-pl011 updates Date: Thu, 03 Sep 2015 19:00:30 +0100 Message-ID: <55E88ABE.2090402@arm.com> References: <20150810232312.GB10728@bivouac.eciton.net> <55E81F93.1020104@arm.com> <20150903155255.GA28336@kroah.com> <55E87095.4030600@arm.com> <55E8880E.5080707@hurleysoftware.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <55E8880E.5080707@hurleysoftware.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: Peter Hurley , Greg Kroah-Hartman Cc: Jun Nie , Tyler Baker , linux-arm-kernel@lists.infradead.org, Leif Lindholm , linux-serial@vger.kernel.org List-Id: linux-serial@vger.kernel.org On 03/09/15 18:49, Peter Hurley wrote: > On 09/03/2015 12:08 PM, Marc Zyngier wrote: >> On 03/09/15 16:52, Greg Kroah-Hartman wrote: >>> On Thu, Sep 03, 2015 at 11:23:15AM +0100, Marc Zyngier wrote: >>>> On 11/08/15 02:48, Jun Nie wrote: >>>>> 2015-08-11 7:23 GMT+08:00 Leif Lindholm : >>>>>> Hi all, >>>>>> >>>>>> The kernelci.org bot picked up a complete boot failure (no output past >>>>>> UEFI stub) with next-20150806 and Tyler bisected it down to somewhere >>>>>> in >>>>>> 8cd90e5 uart: pl011: Add support to ZTE ZX296702 uart >>>>>> 09dcc7d uart: pl011: Improve LCRH register access decision >>>>>> 2c096a9 uart: pl011: Introduce register look up table >>>>>> 7b753f3 uart: pl011: Introduce register accessor >>>>>> >>>>>> The issue only appears with earlycon on command line, for pl011 >>>>>> consoles. >>>>>> >>>>>> Some investigation shows that the cause lies with >>>>>> commit 7b753f318d14 ("uart: pl011: Introduce register accessor") >>>>>> and >>>>>> commit 2c096a9eedc6 ("uart: pl011: Introduce register look up table") >>>>>> >>>>>> Specifically, the changes to pl011_putc() are incorrect: >>>>>> The new pl011_ accessors take a (struct uart_amba_port *) input, but >>>>>> pl011_putc() directly uses the incoming (struct uart_port *) for this. >>>>>> >>>>>> Apart from ending up with an unintended/incorrect UART base address, >>>>>> the introduction of the lookup table for register offsets also means >>>>>> the accessors try to dereference (struct uart_amba_port *)->reg_lut. >>>>>> >>>>>> The below is a hack that shows/resolves the issue, but some >>>>>> refactoring of the original patches might be in order. >>>>>> >>>>>> / >>>>>> Leif >>>>> >>>>> Leif, >>>>> >>>>> Sorry for the inconvenience. I do not have idea of early console till >>>>> now and I always have debug console for early panic debug. Learned >>>>> more from this issue. >>>>> >>>>> Suppose Peter's patch will resolve your issue. >>>> >>>> [+ Greg KH] >>>> >>>> So -next has now been broken for a while on a number of ARM platforms >>>> because of this (they simply cannot boot), and no progress has been made >>>> towards resolving this problem. >>>> >>>> Can we please drop this series (at least commits 7b753f3 and following) >>>> from -next until is has been reworked and reviewed? >>> >>> I don't have any patches in my -next tree, everything is in Linus's tree >>> now. So if I've missed something, or need to revert something, please >>> let me know specifcally what to do. >> >> Gahhh... Given that there is no obvious fix > > Fix has been on list since Aug 10. > > http://www.spinics.net/lists/linux-serial/msg18576.html ... with both Leif and Russell outlining issues with this patch: http://www.spinics.net/lists/linux-serial/msg18594.html http://www.spinics.net/lists/linux-serial/msg18599.html so maybe coming up with an updated series would have been a good move. M. -- Jazz is not dead. It just smells funny...