[U-Boot] Hang when enabling DCache on a iMX6 board

[U-Boot] Hang when enabling DCache on a iMX6 board

[Boris Brezillon]

Hello,

I'm currently porting the SECO iMX6 uQ7 board to mainline, but I'm
facing a hang when enabling DCache (CONFIG_SYS_DCACHE_OFF undefined).
Last week I asked on the #u-boot chan if anybody already encountered
such a bug, and someone (named malik) suggested to check my DDR timings.

After a few more tests and checks I decided to port my changes to an
older version (2014.04), and it apparently works.
I haven't bisected to find the exact commit that makes it fails yet,
but before doing that I'd like to know if anyone else already
experienced this kind of problem, or has any idea of what could cause
this.

Here is my public repository containing two branches [1], the
seco-mainline branch contains my port based on the master branch and
the seco-2014.04 contains the same work based on the 2014.04 tag. 

Best Regards,

Boris

[1]https://github.com/bbrezillon/u-boot-seco

-- 
Boris Brezillon, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com

[U-Boot] Hang when enabling DCache on a iMX6 board

[Anatolij Gustschin]

Hello Boris,

On Tue, 3 Feb 2015 19:39:16 +0100
Boris Brezillon <boris.brezillon@free-electrons.com> wrote:

> Hello,
> 
> I'm currently porting the SECO iMX6 uQ7 board to mainline, but I'm
> facing a hang when enabling DCache (CONFIG_SYS_DCACHE_OFF undefined).
> Last week I asked on the #u-boot chan if anybody already encountered
> such a bug, and someone (named malik) suggested to check my DDR timings.
> 
> After a few more tests and checks I decided to port my changes to an
> older version (2014.04), and it apparently works.
> I haven't bisected to find the exact commit that makes it fails yet,
> but before doing that I'd like to know if anyone else already
> experienced this kind of problem, or has any idea of what could cause
> this.

I've seen similar problem when porting to v2014.04. The problem
disappeared after including the mx6_common.h in the board config
file. This header file contains some errata configs, so please try
with

#include "mx6_common.h"

in your board config file.

HTH,

Anatolij

[U-Boot] Hang when enabling DCache on a iMX6 board

[Boris Brezillon]

Hi Anatolij,

On Tue, 3 Feb 2015 20:17:36 +0100
Anatolij Gustschin <agust@denx.de> wrote:

> Hello Boris,
> 
> On Tue, 3 Feb 2015 19:39:16 +0100
> Boris Brezillon <boris.brezillon@free-electrons.com> wrote:
> 
> > Hello,
> > 
> > I'm currently porting the SECO iMX6 uQ7 board to mainline, but I'm
> > facing a hang when enabling DCache (CONFIG_SYS_DCACHE_OFF undefined).
> > Last week I asked on the #u-boot chan if anybody already encountered
> > such a bug, and someone (named malik) suggested to check my DDR timings.
> > 
> > After a few more tests and checks I decided to port my changes to an
> > older version (2014.04), and it apparently works.
> > I haven't bisected to find the exact commit that makes it fails yet,
> > but before doing that I'd like to know if anyone else already
> > experienced this kind of problem, or has any idea of what could cause
> > this.
> 
> I've seen similar problem when porting to v2014.04. The problem
> disappeared after including the mx6_common.h in the board config
> file. This header file contains some errata configs, so please try
> with
> 
> #include "mx6_common.h"
> 
> in your board config file.

Indeed, it works! \o/

I don't know how, but I somehow included this header when backporting
my work to v2014.04, which explains why it was working on this version.

Anyway, thanks a lot for your answer (I owe you one).

Best Regards,

Boris

-- 
Boris Brezillon, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com