Juno r0 fails to boot with linux-next 20160516

[Mathieu Poirier]

On 16 May 2016 at 11:17, Liviu Dudau <Liviu.Dudau at arm.com> wrote:
> Hi Mathieu,
>
> I was trying to boot linux-next 20150516 today on Juno r0 and it gets stuck
> after printing the message:
>
> Serial: AMBA PL011 UART driver
>
> Bisecting shows commit d02e8a63733ff9121 as the culprit:
>
> commit d02e8a63733ff912128c04a091c0de75be8df1ab
> Author: Mathieu Poirier <mathieu.poirier at linaro.org>
> Date:   Sun Oct 18 16:50:48 2015 -0600
>
>     coresight: Add support for Juno platform
>
>     This patch adds support for ARM's juno platform.  More
>     specifically it has definitions for the A53/57 tracers,
>     the A53/57 cluster funnels, the main funnel and the ETF
>     in circular buffer mode.
>
>     Support for all the other coresight IP blocks is not
>     addressed.
>
>     Signed-off-by: Mathieu Poirier <mathieu.poirier at linaro.org>
>
> Juno r1 is not affected as you are modifying only the juno.dts file. Also,
> if I have the DSTREAM unit connected to the boot core the kernel boots fine,
> which leads me to believe that there is some power domain issue at play (?).
> Also, reverting the patch gets r0 to boot again.
>
> This is the bisection log:
>
> $ git bisect start HEAD v4.6-rc7
> Bisecting: 5755 revisions left to test after this (roughly 13 steps)
> [027e278cc4d21e4718be4ea5bb14e360ff259174] Merge remote-tracking branch 'crypto/master'
> $ git bisect good
> Bisecting: 2836 revisions left to test after this (roughly 12 steps)
> [b14343bae9270c97b7b6b4652157577d2786c591] Merge remote-tracking branch 'tip/auto-latest'
> $ git bisect good
> Bisecting: 1350 revisions left to test after this (roughly 11 steps)
> [98efb6a2745524fc404211e266f54bf409063364] Merge remote-tracking branch 'staging/staging-next'
> $ git bisect good
> Bisecting: 687 revisions left to test after this (roughly 9 steps)
> [ecf549d34f211f9bae0dfab98f994825b0891648] Merge remote-tracking branch 'pwm/for-next'
> $ git bisect good
> Bisecting: 343 revisions left to test after this (roughly 9 steps)
> [fb86798c5cdd615f5c9780eca36a232434f4d63b] nilfs2: fix white space issue in nilfs_mount()
> $ git bisect good
> Bisecting: 158 revisions left to test after this (roughly 8 steps)
> [ae82fd28e602ddab3381d76603a0af9e87a5e2aa] Merge remote-tracking branch 'coresight/next'
> $ git bisect bad
> Bisecting: 92 revisions left to test after this (roughly 7 steps)
> [98b8525abb7f0d9a5ab942a2e044011d7e635490] clk: sunxi: Add display and TCON0 clocks driver
> $ git bisect good
> Bisecting: 51 revisions left to test after this (roughly 6 steps)
> [6d9122078097233dbfc4ad3a45512393cddf8540] Merge branch 'for-4.7/core' into for-next
> $ git bisect good
> Bisecting: 25 revisions left to test after this (roughly 5 steps)
> [25d894772abc89f78512cf640250514be87a3b46] coresight: tmc: introducing new header file
> $ git bisect bad
> Bisecting: 12 revisions left to test after this (roughly 4 steps)
> [63f09f1d779856b615768a97c641ab26126c9183] coresight: no need to do the forced type conversion
> $ git bisect bad
> Bisecting: 6 revisions left to test after this (roughly 3 steps)
> [0cce003868b664547d9e5dd1f586b902cca43784] coresight: etm4x: unlocking tracers in default arch init
> $ git bisect bad
> Bisecting: 2 revisions left to test after this (roughly 2 steps)
> [dd7ebddfdad8d379887f9e2f74d0ba207b59cb77] coresight: etm4x: adding config and traceid registers
> $ git bisect bad
> Bisecting: 0 revisions left to test after this (roughly 1 step)
> [d03196055ea8b535a346239307dfa797bc4059d2] coresight: etm4x: moving sysFS entries to a dedicated file
> $ git bisect bad
> Bisecting: 0 revisions left to test after this (roughly 0 steps)
> [d02e8a63733ff912128c04a091c0de75be8df1ab] coresight: Add support for Juno platform
>
>
> Best regards,
> Liviu

Thank you for pointing this out.  The faulty patch should not have
made it to my next tree in the first place.  I have corrected the
problem.

Regards,
Mathieu

>
> --
> ====================
> | I would like to |
> | fix the world,  |
> | but they're not |
> | giving me the   |
>  \ source code!  /
>   ---------------
>     ¯\_(ツ)_/¯