[PATCH 1/1] ARM: kirkwood: Fix chip-delay for GoFlex Net

[PATCH 1/1] ARM: kirkwood: Fix chip-delay for GoFlex Net

[Eric Hutter]

Hi,

This fixes "Too few good blocks within range" issues on GoFlex Net
by setting chip-delay to 40. I've been using this patch on my device
for quite a while now (accessing uboot vars is not possible without it).
The basic problem was discussed at
http://forum.doozan.com/read.php?2,7451 and I think this fix
should go mainstream.

Greetings

Eric Hutter


Signed-off-by: Eric Hutter <hutter.eric@gmail.com>
---
  arch/arm/boot/dts/kirkwood-goflexnet.dts | 1 +
  1 file changed, 1 insertion(+)

diff --git a/arch/arm/boot/dts/kirkwood-goflexnet.dts 
b/arch/arm/boot/dts/kirkwood-goflexnet.dts
index bd83b8f..c3573be 100644
--- a/arch/arm/boot/dts/kirkwood-goflexnet.dts
+++ b/arch/arm/boot/dts/kirkwood-goflexnet.dts
@@ -77,6 +77,7 @@
          };

          nand at 3000000 {
+            chip-delay = <40>;
              status = "okay";

              partition at 0 {
-- 
1.8.1.4

[PATCH 1/1] ARM: kirkwood: Fix chip-delay for GoFlex Net

[Andrew Lunn]

On Mon, Mar 18, 2013 at 07:48:56PM +0100, Eric Hutter wrote:
> Hi,
> 
> This fixes "Too few good blocks within range" issues on GoFlex Net
> by setting chip-delay to 40.

Hi Eric

Its a problem seen by a couple of other boards as well, e.g. dns320
and dns325.

Acked-by: Andrew Lunn <andrew@lunn.ch>

> Signed-off-by: Eric Hutter <hutter.eric@gmail.com>
> ---
>  arch/arm/boot/dts/kirkwood-goflexnet.dts | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/arch/arm/boot/dts/kirkwood-goflexnet.dts
> b/arch/arm/boot/dts/kirkwood-goflexnet.dts
> index bd83b8f..c3573be 100644
> --- a/arch/arm/boot/dts/kirkwood-goflexnet.dts
> +++ b/arch/arm/boot/dts/kirkwood-goflexnet.dts
> @@ -77,6 +77,7 @@
>          };
> 
>          nand at 3000000 {
> +            chip-delay = <40>;
>              status = "okay";
> 
>              partition at 0 {
> -- 
> 1.8.1.4
> 
> 

[PATCH 1/1] ARM: kirkwood: Fix chip-delay for GoFlex Net

[Jason Gunthorpe]

On Mon, Mar 18, 2013 at 08:26:53PM +0100, Andrew Lunn wrote:
> On Mon, Mar 18, 2013 at 07:48:56PM +0100, Eric Hutter wrote:
> > Hi,
> > 
> > This fixes "Too few good blocks within range" issues on GoFlex Net
> > by setting chip-delay to 40.
> 
> Hi Eric
> 
> Its a problem seen by a couple of other boards as well, e.g. dns320
> and dns325.

The MTD core default of 20us is too small for modern NAND flash.. This
number is based on the chip's datahseet, it should be the longest
non-programming command BUSY interval. Eric, if you haven't already,
it is worth a quick check of the datasheet to verify. Eg the Micron
flash on my Kirkwood system should be 70us.

u-boot can sometimes get away with a smaller value because it only
uses a limited set of commands.

It is on my TODO list to implement ONFI READY/BUSY# pin support in the
orion-nand driver via a GPIO - could other systems make use of this as
well?

Regards,
Jason

[PATCH 1/1] ARM: kirkwood: Fix chip-delay for GoFlex Net

[Jason Cooper]

On Mon, Mar 18, 2013 at 07:48:56PM +0100, Eric Hutter wrote:
> Hi,
> 
> This fixes "Too few good blocks within range" issues on GoFlex Net
> by setting chip-delay to 40. I've been using this patch on my device
> for quite a while now (accessing uboot vars is not possible without it).
> The basic problem was discussed at
> http://forum.doozan.com/read.php?2,7451 and I think this fix
> should go mainstream.
> 
> Greetings
> 
> Eric Hutter
> 
> 
> Signed-off-by: Eric Hutter <hutter.eric@gmail.com>
> ---
>  arch/arm/boot/dts/kirkwood-goflexnet.dts | 1 +
>  1 file changed, 1 insertion(+)

Nice catch!  I'll include this in the next round of fixes I push.

thx,

Jason.

[PATCH 1/1] ARM: kirkwood: Fix chip-delay for GoFlex Net

[Jason Cooper]

On Mon, Mar 18, 2013 at 07:48:56PM +0100, Eric Hutter wrote:
> Hi,
> 
> This fixes "Too few good blocks within range" issues on GoFlex Net
> by setting chip-delay to 40. I've been using this patch on my device
> for quite a while now (accessing uboot vars is not possible without it).
> The basic problem was discussed at
> http://forum.doozan.com/read.php?2,7451 and I think this fix
> should go mainstream.
> 
> Greetings
> 
> Eric Hutter
> 
> 
> Signed-off-by: Eric Hutter <hutter.eric@gmail.com>
> ---

[1] (see below)

>  arch/arm/boot/dts/kirkwood-goflexnet.dts | 1 +
>  1 file changed, 1 insertion(+)

Applied to mvebu/fixes.

I cleaned up the commit message to remove the conversational pieces.  In
the future, you can place this type of info here [1].  When patches are
applied from an email message, everything after the Subject line and
before the '---' becomes the commit message.

I've also Cc'd this to stable for v3.6.x and newer.

thx,

Jason.