From mboxrd@z Thu Jan 1 00:00:00 1970 From: Doug Anderson Subject: Re: Unable to boot mainline on snow chromebook since 3.15 Date: Fri, 5 Sep 2014 13:25:51 -0700 Message-ID: References: <20140905115704.GO13515@arm.com> <20140905122232.GP13515@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Return-path: Received: from mail-vc0-f179.google.com ([209.85.220.179]:36482 "EHLO mail-vc0-f179.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750869AbaIEUZw (ORCPT ); Fri, 5 Sep 2014 16:25:52 -0400 Received: by mail-vc0-f179.google.com with SMTP id hy4so12712160vcb.24 for ; Fri, 05 Sep 2014 13:25:51 -0700 (PDT) In-Reply-To: <20140905122232.GP13515@arm.com> Sender: linux-samsung-soc-owner@vger.kernel.org List-Id: linux-samsung-soc@vger.kernel.org To: Will Deacon Cc: "kgene.kim@samsung.com" , "olof@lixom.net" , "rahul.sharma@samsung.com" , "linux-arm-kernel@lists.infradead.org" , "linux-samsung-soc@vger.kernel.org" , Javier Martinez Canillas Will, On Fri, Sep 5, 2014 at 5:22 AM, Will Deacon wrote: > [Looks like it's not just Rutland that can't spell the address of the > mailing list today. Fixed here, so please use this post in any replies]. > > On Fri, Sep 05, 2014 at 12:57:04PM +0100, Will Deacon wrote: >> Hi all, >> >> I'm one of the few, foolish people to try running mainline on my 5250-based >> Samsung Chromebook (snow). I can live without wireless, usb3 and video >> acceleration, so actually it makes a reasonable development platform for >> doing A15-based (micro)-architectural work. >> >> However, since 3.15 I've not been able to boot *any* mainline kernels on >> this board. I did mean to report this earlier, but I have other machines >> that can run mainline so this has fallen by the wayside. >> >> The problems started with 3.16, where simple-fb would fail to initialise >> and I lost my display. Note that I don't have a serial console on this >> machine (I looked at the PCB and there's no way I can solder one of those >> myself :) I bisected the issue at the time, and I could get my display back >> by removing some of the new regulator and hdmi properties from the DT. At >> that point, I could boot, but DMA didn't initialise for the MMC controller >> so I couldn't mount my root filesystem. >> >> With 3.17-rc3, it seems a lot worse -- I don't get any output after nv-uboot >> (i.e. the nv-uboot screen just remains on the display, with the last line >> reading "Stashed 20 records"). >> >> I'd usually try to debug this a bit further, but without a console it's >> really painful to get anywhere. I've been working with 3.15, but now I'm >> having to backport patches when I want to test them, which is more effort >> than I can be bothered with. >> >> Is anybody else running mainline on this device and are these known/fixed >> problems? I've added Javier, who says he'll try to take a look at the problem on Monday. He's got a snow and I think he's got a serial console hooked up to it (but I don't think he's tried the simplefb workflow). He also added the following thoughts: > Have you seen the very long "[PATCH 4/4] simplefb: add clock handling > code" thread [0]?. I wonder if the problem is that the display clocks were > not known to the kernel before 3.15 but now are getting disabled and thus > the simplefb driver not working? > > So probably is worth to try passing clk_ignore_unused as a parameter to > the kernel command line. > > [0]: https://www.mail-archive.com/linux-sunxi@googlegroups.com/msg06623.html From mboxrd@z Thu Jan 1 00:00:00 1970 From: dianders@chromium.org (Doug Anderson) Date: Fri, 5 Sep 2014 13:25:51 -0700 Subject: Unable to boot mainline on snow chromebook since 3.15 In-Reply-To: <20140905122232.GP13515@arm.com> References: <20140905115704.GO13515@arm.com> <20140905122232.GP13515@arm.com> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Will, On Fri, Sep 5, 2014 at 5:22 AM, Will Deacon wrote: > [Looks like it's not just Rutland that can't spell the address of the > mailing list today. Fixed here, so please use this post in any replies]. > > On Fri, Sep 05, 2014 at 12:57:04PM +0100, Will Deacon wrote: >> Hi all, >> >> I'm one of the few, foolish people to try running mainline on my 5250-based >> Samsung Chromebook (snow). I can live without wireless, usb3 and video >> acceleration, so actually it makes a reasonable development platform for >> doing A15-based (micro)-architectural work. >> >> However, since 3.15 I've not been able to boot *any* mainline kernels on >> this board. I did mean to report this earlier, but I have other machines >> that can run mainline so this has fallen by the wayside. >> >> The problems started with 3.16, where simple-fb would fail to initialise >> and I lost my display. Note that I don't have a serial console on this >> machine (I looked at the PCB and there's no way I can solder one of those >> myself :) I bisected the issue at the time, and I could get my display back >> by removing some of the new regulator and hdmi properties from the DT. At >> that point, I could boot, but DMA didn't initialise for the MMC controller >> so I couldn't mount my root filesystem. >> >> With 3.17-rc3, it seems a lot worse -- I don't get any output after nv-uboot >> (i.e. the nv-uboot screen just remains on the display, with the last line >> reading "Stashed 20 records"). >> >> I'd usually try to debug this a bit further, but without a console it's >> really painful to get anywhere. I've been working with 3.15, but now I'm >> having to backport patches when I want to test them, which is more effort >> than I can be bothered with. >> >> Is anybody else running mainline on this device and are these known/fixed >> problems? I've added Javier, who says he'll try to take a look at the problem on Monday. He's got a snow and I think he's got a serial console hooked up to it (but I don't think he's tried the simplefb workflow). He also added the following thoughts: > Have you seen the very long "[PATCH 4/4] simplefb: add clock handling > code" thread [0]?. I wonder if the problem is that the display clocks were > not known to the kernel before 3.15 but now are getting disabled and thus > the simplefb driver not working? > > So probably is worth to try passing clk_ignore_unused as a parameter to > the kernel command line. > > [0]: https://www.mail-archive.com/linux-sunxi at googlegroups.com/msg06623.html