From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Hurley Subject: Re: earlycon issues in -next with amba-pl011 updates Date: Thu, 3 Sep 2015 13:49:02 -0400 Message-ID: <55E8880E.5080707@hurleysoftware.com> References: <20150810232312.GB10728@bivouac.eciton.net> <55E81F93.1020104@arm.com> <20150903155255.GA28336@kroah.com> <55E87095.4030600@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <55E87095.4030600@arm.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: Marc Zyngier , 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 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 > that the discussion has > stalled and that the author of the series is apparently away, the > following patches should be reverted: > > 8cd90e50d140 uart: pl011: Add support to ZTE ZX296702 uart > 09dcc7dfc05b uart: pl011: Improve LCRH register access decision > 2c096a9eedc6 uart: pl011: Introduce register look up table > 7b753f318d14 uart: pl011: Introduce register accessor > 534e14e2293d uart: pl011: Rename regs with enumeration > > (7b753f318d14 being the one breaking everything, but it makes more sense > to revert the whole series until it is properly fixed and reviewed). > > Thanks, > > M. >