Patchwork [U-Boot,1/4] arm/km: fix memory settings

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Submitter Holger Brunck
Date Nov. 2, 2012, 10:15 a.m.
Message ID <1351851310-8463-1-git-send-email-holger.brunck@keymile.com>
Download mbox | patch
Permalink /patch/196530/
State Accepted
Delegated to: Prafulla Wadaskar
Headers show

Comments

Holger Brunck - Nov. 2, 2012, 10:15 a.m.
On kmcoge5un we faced some serious problems with the memory during
temperature tests. Reason was that we overwrite some registers for
memory settings which have to leave untouched. These where registers
0x20148 , 0x2014c and 0x20154.
So writing these registers is prohibited and this patch removes them
from all km related config files. Even if the problem was only
seen on kmcoge5un.

Signed-off-by: Holger Brunck <holger.brunck@keymile.com>
Signed-off-by: Valentin Longchamp <valentin.longchamp@keymile.com>
cc: Prafulla Wadaskar <prafulla@marvell.com>
---
 board/keymile/km_arm/kwbimage-memphis.cfg  |    6 +++---
 board/keymile/km_arm/kwbimage.cfg          |    6 +++---
 board/keymile/km_arm/kwbimage_128M16_1.cfg |   25 ++-----------------------
 board/keymile/km_arm/kwbimage_256M8_1.cfg  |   25 ++-----------------------
 4 files changed, 10 insertions(+), 52 deletions(-)
Prafulla Wadaskar - Nov. 10, 2012, 7:19 a.m.
> -----Original Message-----
> From: Holger Brunck [mailto:holger.brunck@keymile.com]
> Sent: 02 November 2012 15:45
> To: u-boot@lists.denx.de
> Cc: Holger Brunck; Valentin Longchamp; Prafulla Wadaskar
> Subject: [PATCH 1/4] arm/km: fix memory settings
> 
> On kmcoge5un we faced some serious problems with the memory during
> temperature tests. Reason was that we overwrite some registers for
> memory settings which have to leave untouched. These where registers
> 0x20148 , 0x2014c and 0x20154.
> So writing these registers is prohibited and this patch removes them
> from all km related config files. Even if the problem was only
> seen on kmcoge5un.
> 
> Signed-off-by: Holger Brunck <holger.brunck@keymile.com>
> Signed-off-by: Valentin Longchamp <valentin.longchamp@keymile.com>
> cc: Prafulla Wadaskar <prafulla@marvell.com>
> ---
>  board/keymile/km_arm/kwbimage-memphis.cfg  |    6 +++---
>  board/keymile/km_arm/kwbimage.cfg          |    6 +++---
>  board/keymile/km_arm/kwbimage_128M16_1.cfg |   25 ++-----------------
> ------
>  board/keymile/km_arm/kwbimage_256M8_1.cfg  |   25 ++-----------------
> ------
>  4 files changed, 10 insertions(+), 52 deletions(-)
> 
> diff --git a/board/keymile/km_arm/kwbimage-memphis.cfg
> b/board/keymile/km_arm/kwbimage-memphis.cfg
> index 6df2ad7..5aa0de2 100644
> --- a/board/keymile/km_arm/kwbimage-memphis.cfg
> +++ b/board/keymile/km_arm/kwbimage-memphis.cfg
> @@ -55,9 +55,9 @@ DATA 0xFFD10008 0x00001100	# MPP Control 2
> Register
>  DATA 0xFFD100E0 0x1B1B1B1B	# IO Configuration 0 Register
>  DATA 0xFFD20134 0x66666666	# L2 RAM Timing 0 Register
>  DATA 0xFFD20138 0x66666666	# L2 RAM Timing 1 Register
> -DATA 0xFFD20154 0x00000200	# CPU RAM Management Control3 Register
> -DATA 0xFFD2014C 0x00001C00	# CPU RAM Management Control1 Register
> -DATA 0xFFD20148 0x00000001	# CPU RAM Management Control0 Register

I think this should be applicable to other Kirkwood boards too.

> +
> +# NOTE: Don't write on 0x20148 , 0x2014c and 0x20154, leave them
> untouched!
> +# If not it could cause KW Exceptions during boot in Fast
> Corners/High Voltage

Since you are removing above three lines, do you think the above comments are needed in this cfg file? I think you can even remove these comments too because you are not at all providing configuration for this address.

I think simple you can remove these lines from the code.

Same applicable for rest of the files too.

Regards...
Prafulla . . .
Holger Brunck - Nov. 12, 2012, 10:26 a.m.
Hi Prafulla,

On 11/10/2012 08:19 AM, Prafulla Wadaskar wrote:
>> On kmcoge5un we faced some serious problems with the memory during
>> temperature tests. Reason was that we overwrite some registers for
>> memory settings which have to leave untouched. These where registers
>> 0x20148 , 0x2014c and 0x20154.
>> So writing these registers is prohibited and this patch removes them
>> from all km related config files. Even if the problem was only
>> seen on kmcoge5un.
>>
>> Signed-off-by: Holger Brunck <holger.brunck@keymile.com>
>> Signed-off-by: Valentin Longchamp <valentin.longchamp@keymile.com>
>> cc: Prafulla Wadaskar <prafulla@marvell.com>
>> ---
>>  board/keymile/km_arm/kwbimage-memphis.cfg  |    6 +++---
>>  board/keymile/km_arm/kwbimage.cfg          |    6 +++---
>>  board/keymile/km_arm/kwbimage_128M16_1.cfg |   25 ++-----------------
>> ------
>>  board/keymile/km_arm/kwbimage_256M8_1.cfg  |   25 ++-----------------
>> ------
>>  4 files changed, 10 insertions(+), 52 deletions(-)
>>
>> diff --git a/board/keymile/km_arm/kwbimage-memphis.cfg
>> b/board/keymile/km_arm/kwbimage-memphis.cfg
>> index 6df2ad7..5aa0de2 100644
>> --- a/board/keymile/km_arm/kwbimage-memphis.cfg
>> +++ b/board/keymile/km_arm/kwbimage-memphis.cfg
>> @@ -55,9 +55,9 @@ DATA 0xFFD10008 0x00001100	# MPP Control 2
>> Register
>>  DATA 0xFFD100E0 0x1B1B1B1B	# IO Configuration 0 Register
>>  DATA 0xFFD20134 0x66666666	# L2 RAM Timing 0 Register
>>  DATA 0xFFD20138 0x66666666	# L2 RAM Timing 1 Register
>> -DATA 0xFFD20154 0x00000200	# CPU RAM Management Control3 Register
>> -DATA 0xFFD2014C 0x00001C00	# CPU RAM Management Control1 Register
>> -DATA 0xFFD20148 0x00000001	# CPU RAM Management Control0 Register
> 
> I think this should be applicable to other Kirkwood boards too.
> 
>> +
>> +# NOTE: Don't write on 0x20148 , 0x2014c and 0x20154, leave them
>> untouched!
>> +# If not it could cause KW Exceptions during boot in Fast
>> Corners/High Voltage
> 
> Since you are removing above three lines, do you think the above comments are needed in this cfg file? I think you can even remove these comments too because you are not at all providing configuration for this address.
> 
> I think simple you can remove these lines from the code.
>

The comment was meant to be a warning for us for the future because the problems
which are due to this writes were hard to debug.

I would like to keep them and due to the fact that these are
"km only" files it should do no harm. But if you still insist I could also drop
them. Just let me know.

Regards
Holger
Prafulla Wadaskar - Nov. 12, 2012, 10:42 a.m.
> -----Original Message-----
> From: Holger Brunck [mailto:holger.brunck@keymile.com]
> Sent: 12 November 2012 15:57
> To: Prafulla Wadaskar
> Cc: u-boot@lists.denx.de; Valentin Longchamp
> Subject: Re: [PATCH 1/4] arm/km: fix memory settings
> 
> Hi Prafulla,
> 
> On 11/10/2012 08:19 AM, Prafulla Wadaskar wrote:
> >> On kmcoge5un we faced some serious problems with the memory during
> >> temperature tests. Reason was that we overwrite some registers for
> >> memory settings which have to leave untouched. These where
> registers
> >> 0x20148 , 0x2014c and 0x20154.
> >> So writing these registers is prohibited and this patch removes
> them
> >> from all km related config files. Even if the problem was only
> >> seen on kmcoge5un.
> >>
> >> Signed-off-by: Holger Brunck <holger.brunck@keymile.com>
> >> Signed-off-by: Valentin Longchamp <valentin.longchamp@keymile.com>
> >> cc: Prafulla Wadaskar <prafulla@marvell.com>
> >> ---
> >>  board/keymile/km_arm/kwbimage-memphis.cfg  |    6 +++---
> >>  board/keymile/km_arm/kwbimage.cfg          |    6 +++---
> >>  board/keymile/km_arm/kwbimage_128M16_1.cfg |   25 ++--------------
> ---
> >> ------
> >>  board/keymile/km_arm/kwbimage_256M8_1.cfg  |   25 ++--------------
> ---
> >> ------
> >>  4 files changed, 10 insertions(+), 52 deletions(-)
> >>
> >> diff --git a/board/keymile/km_arm/kwbimage-memphis.cfg
> >> b/board/keymile/km_arm/kwbimage-memphis.cfg
> >> index 6df2ad7..5aa0de2 100644
> >> --- a/board/keymile/km_arm/kwbimage-memphis.cfg
> >> +++ b/board/keymile/km_arm/kwbimage-memphis.cfg
> >> @@ -55,9 +55,9 @@ DATA 0xFFD10008 0x00001100	# MPP Control 2
> >> Register
> >>  DATA 0xFFD100E0 0x1B1B1B1B	# IO Configuration 0 Register
> >>  DATA 0xFFD20134 0x66666666	# L2 RAM Timing 0 Register
> >>  DATA 0xFFD20138 0x66666666	# L2 RAM Timing 1 Register
> >> -DATA 0xFFD20154 0x00000200	# CPU RAM Management Control3
> Register
> >> -DATA 0xFFD2014C 0x00001C00	# CPU RAM Management Control1
> Register
> >> -DATA 0xFFD20148 0x00000001	# CPU RAM Management Control0
> Register
> >
> > I think this should be applicable to other Kirkwood boards too.
> >
> >> +
> >> +# NOTE: Don't write on 0x20148 , 0x2014c and 0x20154, leave them
> >> untouched!
> >> +# If not it could cause KW Exceptions during boot in Fast
> >> Corners/High Voltage
> >
> > Since you are removing above three lines, do you think the above
> comments are needed in this cfg file? I think you can even remove
> these comments too because you are not at all providing configuration
> for this address.
> >
> > I think simple you can remove these lines from the code.
> >
> 
> The comment was meant to be a warning for us for the future because
> the problems
> which are due to this writes were hard to debug.
> 
> I would like to keep them and due to the fact that these are
> "km only" files it should do no harm. But if you still insist I could
> also drop
> them. Just let me know.

No need, that's your call :-) I will pull it.


Regards...
Prafulla . . .
Holger Brunck - Dec. 17, 2012, 12:42 p.m.
Hi Prafulla,

On 11/02/2012 11:15 AM, Holger Brunck wrote:
> On kmcoge5un we faced some serious problems with the memory during
> temperature tests. Reason was that we overwrite some registers for
> memory settings which have to leave untouched. These where registers
> 0x20148 , 0x2014c and 0x20154.
> So writing these registers is prohibited and this patch removes them
> from all km related config files. Even if the problem was only
> seen on kmcoge5un.
> 
> Signed-off-by: Holger Brunck <holger.brunck@keymile.com>
> Signed-off-by: Valentin Longchamp <valentin.longchamp@keymile.com>
> cc: Prafulla Wadaskar <prafulla@marvell.com>
> ---
>  board/keymile/km_arm/kwbimage-memphis.cfg  |    6 +++---
>  board/keymile/km_arm/kwbimage.cfg          |    6 +++---
>  board/keymile/km_arm/kwbimage_128M16_1.cfg |   25 ++-----------------------
>  board/keymile/km_arm/kwbimage_256M8_1.cfg  |   25 ++-----------------------
>  4 files changed, 10 insertions(+), 52 deletions(-)
> 

what about this patch serie? They were posted long time ago and we are already
at -rc2 and they are sitting wether in the ARM tree nor in your marvell tree. So
could you please pick up these four?

Thanks,
Holger
Prafulla Wadaskar - Dec. 17, 2012, 12:51 p.m.
> -----Original Message-----
> From: Holger Brunck [mailto:holger.brunck@keymile.com]
> Sent: 17 December 2012 18:13
> To: Prafulla Wadaskar
> Cc: u-boot@lists.denx.de; albert.u.boot@aribaud.net; Longchamp,
> Valentin
> Subject: Re: [PATCH 1/4] arm/km: fix memory settings
> 
> Hi Prafulla,
> 
> On 11/02/2012 11:15 AM, Holger Brunck wrote:
> > On kmcoge5un we faced some serious problems with the memory during
> > temperature tests. Reason was that we overwrite some registers for
> > memory settings which have to leave untouched. These where registers
> > 0x20148 , 0x2014c and 0x20154.
> > So writing these registers is prohibited and this patch removes them
> > from all km related config files. Even if the problem was only
> > seen on kmcoge5un.
> >
> > Signed-off-by: Holger Brunck <holger.brunck@keymile.com>
> > Signed-off-by: Valentin Longchamp <valentin.longchamp@keymile.com>
> > cc: Prafulla Wadaskar <prafulla@marvell.com>
> > ---
> >  board/keymile/km_arm/kwbimage-memphis.cfg  |    6 +++---
> >  board/keymile/km_arm/kwbimage.cfg          |    6 +++---
> >  board/keymile/km_arm/kwbimage_128M16_1.cfg |   25 ++---------------
> --------
> >  board/keymile/km_arm/kwbimage_256M8_1.cfg  |   25 ++---------------
> --------
> >  4 files changed, 10 insertions(+), 52 deletions(-)
> >
> 
> what about this patch serie? They were posted long time ago and we are
> already
> at -rc2 and they are sitting wether in the ARM tree nor in your
> marvell tree. So
> could you please pick up these four?

Sure, I am doing the same, I will provide the pull request today.

Regards...
Prafulla . . .
Prafulla Wadaskar - Dec. 20, 2012, 6:38 a.m.
> -----Original Message-----
> From: Holger Brunck [mailto:holger.brunck@keymile.com]
> Sent: 02 November 2012 15:45
> To: u-boot@lists.denx.de
> Cc: Holger Brunck; Valentin Longchamp; Prafulla Wadaskar
> Subject: [PATCH 1/4] arm/km: fix memory settings
> 
> On kmcoge5un we faced some serious problems with the memory during
> temperature tests. Reason was that we overwrite some registers for
> memory settings which have to leave untouched. These where registers
> 0x20148 , 0x2014c and 0x20154.
> So writing these registers is prohibited and this patch removes them
> from all km related config files. Even if the problem was only
> seen on kmcoge5un.
> 
> Signed-off-by: Holger Brunck <holger.brunck@keymile.com>
> Signed-off-by: Valentin Longchamp <valentin.longchamp@keymile.com>
> cc: Prafulla Wadaskar <prafulla@marvell.com>
> ---
>  board/keymile/km_arm/kwbimage-memphis.cfg  |    6 +++---
>  board/keymile/km_arm/kwbimage.cfg          |    6 +++---
>  board/keymile/km_arm/kwbimage_128M16_1.cfg |   25 ++-----------------
> ------
>  board/keymile/km_arm/kwbimage_256M8_1.cfg  |   25 ++-----------------
> ------
>  4 files changed, 10 insertions(+), 52 deletions(-)
> 
> diff --git a/board/keymile/km_arm/kwbimage-memphis.cfg
> b/board/keymile/km_arm/kwbimage-memphis.cfg
> index 6df2ad7..5aa0de2 100644
> --- a/board/keymile/km_arm/kwbimage-memphis.cfg
> +++ b/board/keymile/km_arm/kwbimage-memphis.cfg
> @@ -55,9 +55,9 @@ DATA 0xFFD10008 0x00001100	# MPP Control 2
> Register
>  DATA 0xFFD100E0 0x1B1B1B1B	# IO Configuration 0 Register
>  DATA 0xFFD20134 0x66666666	# L2 RAM Timing 0 Register
>  DATA 0xFFD20138 0x66666666	# L2 RAM Timing 1 Register
> -DATA 0xFFD20154 0x00000200	# CPU RAM Management Control3 Register
> -DATA 0xFFD2014C 0x00001C00	# CPU RAM Management Control1 Register
> -DATA 0xFFD20148 0x00000001	# CPU RAM Management Control0 Register
> +
> +# NOTE: Don't write on 0x20148 , 0x2014c and 0x20154, leave them
> untouched!
> +# If not it could cause KW Exceptions during boot in Fast
> Corners/High Voltage
> 
>  #Dram initalization
>  DATA 0xFFD01400 0x430004E0	# SDRAM Configuration Register
> diff --git a/board/keymile/km_arm/kwbimage.cfg
> b/board/keymile/km_arm/kwbimage.cfg
> index b2f5193..e5e9942 100644
> --- a/board/keymile/km_arm/kwbimage.cfg
> +++ b/board/keymile/km_arm/kwbimage.cfg
> @@ -52,9 +52,9 @@ DATA 0xFFD10008 0x00001100	# MPP Control 2
> Register
>  DATA 0xFFD100E0 0x1B1B1B1B	# IO Configuration 0 Register
>  DATA 0xFFD20134 0x66666666	# L2 RAM Timing 0 Register
>  DATA 0xFFD20138 0x66666666	# L2 RAM Timing 1 Register
> -DATA 0xFFD20154 0x00000200	# CPU RAM Management Control3 Register
> -DATA 0xFFD2014C 0x00001C00	# CPU RAM Management Control1 Register
> -DATA 0xFFD20148 0x00000001	# CPU RAM Management Control0 Register
> +
> +# NOTE: Don't write on 0x20148 , 0x2014c and 0x20154, leave them
> untouched!
> +# If not it could cause KW Exceptions during boot in Fast
> Corners/High Voltage
> 
>  #Dram initalization
>  DATA 0xFFD01400 0x43000400	# SDRAM Configuration Register
> diff --git a/board/keymile/km_arm/kwbimage_128M16_1.cfg
> b/board/keymile/km_arm/kwbimage_128M16_1.cfg
> index bcce907..5de8df7 100644
> --- a/board/keymile/km_arm/kwbimage_128M16_1.cfg
> +++ b/board/keymile/km_arm/kwbimage_128M16_1.cfg
> @@ -98,29 +98,8 @@ DATA 0xFFD20138 0x66666666	# L2 RAM Timing 1
> Register
>  # bit 19-18: 1, ECC RAM WTC RAM0
>  # bit 31-20: ???,Reserve
> 
> -DATA 0xFFD20154 0x00000200	# CPU RAM Management Control3 Register
> -# bit 23-0:  0x000200, Addr Config tuning
> -# bit 31-24: 0,        Reserved
> -
> -# ??? Missing register # CPU RAM Management Control2 Register
> -
> -DATA 0xFFD2014C 0x00001C00	# CPU RAM Management Control1 Register
> -# bit 15-0:  0x1C00, Opmux Tuning
> -# bit 31-16: 0,      Pc Dp Tuning
> -
> -DATA 0xFFD20148 0x00000001	# CPU RAM Management Control0 Register
> -# bit 1-0:   1, addr clk tune
> -# bit 3-2:   0, reserved
> -# bit 5-4:   0, dtcmp clk tune
> -# bit 7-6:   0, reserved
> -# bit 9-8:   0, macdrv clk tune
> -# bit 11-10: 0, opmuxgm2 clk tune
> -# bit 15-14: 0, rf clk tune
> -# bit 17-16: 0, rfbypass clk tune
> -# bit 19-18: 0, pc dp clk tune
> -# bit 23-20: 0, icache clk tune
> -# bit 27:24: 0, dcache clk tune
> -# bit 31:28: 0, regfile tunin
> +# NOTE: Don't write on 0x20148 , 0x2014c and 0x20154, leave them
> untouched!
> +# If not it could cause KW Exceptions during boot in Fast
> Corners/High Voltage
> 
>  # SDRAM initalization
>  DATA 0xFFD01400 0x430004E0	# SDRAM Configuration Register
> diff --git a/board/keymile/km_arm/kwbimage_256M8_1.cfg
> b/board/keymile/km_arm/kwbimage_256M8_1.cfg
> index 3e1237b..d0a09f6 100644
> --- a/board/keymile/km_arm/kwbimage_256M8_1.cfg
> +++ b/board/keymile/km_arm/kwbimage_256M8_1.cfg
> @@ -100,29 +100,8 @@ DATA 0xFFD20138 0x66666666	# L2 RAM Timing 1
> Register
>  # bit 19-18: 1, ECC RAM WTC RAM0
>  # bit 31-20: ?,Reserved
> 
> -DATA 0xFFD20154 0x00000200	# CPU RAM Management Control3 Register
> -# bit 23-0:  0x000200, Addr Config tuning
> -# bit 31-24: 0,        Reserved
> -
> -# ??? Missing register # CPU RAM Management Control2 Register
> -
> -DATA 0xFFD2014C 0x00001C00	# CPU RAM Management Control1 Register
> -# bit 15-0:  0x1C00, Opmux Tuning
> -# bit 31-16: 0,      Pc Dp Tuning
> -
> -DATA 0xFFD20148 0x00000001	# CPU RAM Management Control0 Register
> -# bit 1-0:   1, addr clk tune
> -# bit 3-2:   0, reserved
> -# bit 5-4:   0, dtcmp clk tune
> -# bit 7-6:   0, reserved
> -# bit 9-8:   0, macdrv clk tune
> -# bit 11-10: 0, opmuxgm2 clk tune
> -# bit 15-14: 0, rf clk tune
> -# bit 17-16: 0, rfbypass clk tune
> -# bit 19-18: 0, pc dp clk tune
> -# bit 23-20: 0, icache clk tune
> -# bit 27:24: 0, dcache clk tune
> -# bit 31:28: 0, regfile tunin
> +# NOTE: Don't write on 0x20148 , 0x2014c and 0x20154, leave them
> untouched!
> +# If not it could cause KW Exceptions during boot in Fast
> Corners/High Voltage
> 
>  # SDRAM initalization
>  DATA 0xFFD01400 0x430004E0	# SDRAM Configuration Register
> --
> 1.7.1

Applied to u-boot-marvell.git master branch

Regards...
Prafulla . . .

Patch

diff --git a/board/keymile/km_arm/kwbimage-memphis.cfg b/board/keymile/km_arm/kwbimage-memphis.cfg
index 6df2ad7..5aa0de2 100644
--- a/board/keymile/km_arm/kwbimage-memphis.cfg
+++ b/board/keymile/km_arm/kwbimage-memphis.cfg
@@ -55,9 +55,9 @@  DATA 0xFFD10008 0x00001100	# MPP Control 2 Register
 DATA 0xFFD100E0 0x1B1B1B1B	# IO Configuration 0 Register
 DATA 0xFFD20134 0x66666666	# L2 RAM Timing 0 Register
 DATA 0xFFD20138 0x66666666	# L2 RAM Timing 1 Register
-DATA 0xFFD20154 0x00000200	# CPU RAM Management Control3 Register
-DATA 0xFFD2014C 0x00001C00	# CPU RAM Management Control1 Register
-DATA 0xFFD20148 0x00000001	# CPU RAM Management Control0 Register
+
+# NOTE: Don't write on 0x20148 , 0x2014c and 0x20154, leave them untouched!
+# If not it could cause KW Exceptions during boot in Fast Corners/High Voltage
 
 #Dram initalization
 DATA 0xFFD01400 0x430004E0	# SDRAM Configuration Register
diff --git a/board/keymile/km_arm/kwbimage.cfg b/board/keymile/km_arm/kwbimage.cfg
index b2f5193..e5e9942 100644
--- a/board/keymile/km_arm/kwbimage.cfg
+++ b/board/keymile/km_arm/kwbimage.cfg
@@ -52,9 +52,9 @@  DATA 0xFFD10008 0x00001100	# MPP Control 2 Register
 DATA 0xFFD100E0 0x1B1B1B1B	# IO Configuration 0 Register
 DATA 0xFFD20134 0x66666666	# L2 RAM Timing 0 Register
 DATA 0xFFD20138 0x66666666	# L2 RAM Timing 1 Register
-DATA 0xFFD20154 0x00000200	# CPU RAM Management Control3 Register
-DATA 0xFFD2014C 0x00001C00	# CPU RAM Management Control1 Register
-DATA 0xFFD20148 0x00000001	# CPU RAM Management Control0 Register
+
+# NOTE: Don't write on 0x20148 , 0x2014c and 0x20154, leave them untouched!
+# If not it could cause KW Exceptions during boot in Fast Corners/High Voltage
 
 #Dram initalization
 DATA 0xFFD01400 0x43000400	# SDRAM Configuration Register
diff --git a/board/keymile/km_arm/kwbimage_128M16_1.cfg b/board/keymile/km_arm/kwbimage_128M16_1.cfg
index bcce907..5de8df7 100644
--- a/board/keymile/km_arm/kwbimage_128M16_1.cfg
+++ b/board/keymile/km_arm/kwbimage_128M16_1.cfg
@@ -98,29 +98,8 @@  DATA 0xFFD20138 0x66666666	# L2 RAM Timing 1 Register
 # bit 19-18: 1, ECC RAM WTC RAM0
 # bit 31-20: ???,Reserve
 
-DATA 0xFFD20154 0x00000200	# CPU RAM Management Control3 Register
-# bit 23-0:  0x000200, Addr Config tuning
-# bit 31-24: 0,        Reserved
-
-# ??? Missing register # CPU RAM Management Control2 Register
-
-DATA 0xFFD2014C 0x00001C00	# CPU RAM Management Control1 Register
-# bit 15-0:  0x1C00, Opmux Tuning
-# bit 31-16: 0,      Pc Dp Tuning
-
-DATA 0xFFD20148 0x00000001	# CPU RAM Management Control0 Register
-# bit 1-0:   1, addr clk tune
-# bit 3-2:   0, reserved
-# bit 5-4:   0, dtcmp clk tune
-# bit 7-6:   0, reserved
-# bit 9-8:   0, macdrv clk tune
-# bit 11-10: 0, opmuxgm2 clk tune
-# bit 15-14: 0, rf clk tune
-# bit 17-16: 0, rfbypass clk tune
-# bit 19-18: 0, pc dp clk tune
-# bit 23-20: 0, icache clk tune
-# bit 27:24: 0, dcache clk tune
-# bit 31:28: 0, regfile tunin
+# NOTE: Don't write on 0x20148 , 0x2014c and 0x20154, leave them untouched!
+# If not it could cause KW Exceptions during boot in Fast Corners/High Voltage
 
 # SDRAM initalization
 DATA 0xFFD01400 0x430004E0	# SDRAM Configuration Register
diff --git a/board/keymile/km_arm/kwbimage_256M8_1.cfg b/board/keymile/km_arm/kwbimage_256M8_1.cfg
index 3e1237b..d0a09f6 100644
--- a/board/keymile/km_arm/kwbimage_256M8_1.cfg
+++ b/board/keymile/km_arm/kwbimage_256M8_1.cfg
@@ -100,29 +100,8 @@  DATA 0xFFD20138 0x66666666	# L2 RAM Timing 1 Register
 # bit 19-18: 1, ECC RAM WTC RAM0
 # bit 31-20: ?,Reserved
 
-DATA 0xFFD20154 0x00000200	# CPU RAM Management Control3 Register
-# bit 23-0:  0x000200, Addr Config tuning
-# bit 31-24: 0,        Reserved
-
-# ??? Missing register # CPU RAM Management Control2 Register
-
-DATA 0xFFD2014C 0x00001C00	# CPU RAM Management Control1 Register
-# bit 15-0:  0x1C00, Opmux Tuning
-# bit 31-16: 0,      Pc Dp Tuning
-
-DATA 0xFFD20148 0x00000001	# CPU RAM Management Control0 Register
-# bit 1-0:   1, addr clk tune
-# bit 3-2:   0, reserved
-# bit 5-4:   0, dtcmp clk tune
-# bit 7-6:   0, reserved
-# bit 9-8:   0, macdrv clk tune
-# bit 11-10: 0, opmuxgm2 clk tune
-# bit 15-14: 0, rf clk tune
-# bit 17-16: 0, rfbypass clk tune
-# bit 19-18: 0, pc dp clk tune
-# bit 23-20: 0, icache clk tune
-# bit 27:24: 0, dcache clk tune
-# bit 31:28: 0, regfile tunin
+# NOTE: Don't write on 0x20148 , 0x2014c and 0x20154, leave them untouched!
+# If not it could cause KW Exceptions during boot in Fast Corners/High Voltage
 
 # SDRAM initalization
 DATA 0xFFD01400 0x430004E0	# SDRAM Configuration Register