[PATCH] mtd: mxc_nand: Set timing for v2 controllers

On Fri, 2 Sep 2016 14:43:53 +0200
Sascha Hauer [off-list ref] wrote:

On Mon, Aug 29, 2016 at 10:50:50AM +0200, Boris Brezillon wrote:

quoted

Hi Sascha,

On Mon, 29 Aug 2016 10:35:58 +0200
Sascha Hauer [off-list ref] wrote:
  

quoted

Hi Boris,

On Fri, Aug 26, 2016 at 09:46:53AM +0200, Boris Brezillon wrote:  

quoted

Hi Sascha,

On Tue, 23 Aug 2016 12:34:05 +0200
Sascha Hauer [off-list ref] wrote:

AFAIR, you should apply the new mode on the NAND side
(ONFI_FEATURE_ADDR_TIMING_MODE) before applying the new config to the
controller.

See what's done here [1].

Note that on all the NANDs I tested, it seems to work even if you don't
set ONFI_FEATURE_ADDR_TIMING_MODE, but the ONFI Spec describes the
procedure as:    

Indeed, works here without notifying the NAND chip aswell. I wasn't even
aware that there is a possibility to notify the NAND chip.
  

quoted

1/ detect supported modes
2/ select one
3/ apply it to the NAND using set(ONFI_FEATURE_ADDR_TIMING_MODE)
4/ release the CS
5/ adjust the controller setting to match the new config

On a side note, I really think we should handle this timing selection in
the core, and only ask the NAND controller drivers to adapt the
controller settings.    

I agree that the core should do this. Do you already have any thoughts
how the API could could look like?  

I already provided a simple implementation a while ago [1]. Not sure it
handles all the corner cases though.  

I just picked up the patch and ported my mxc_nand patch over to it. See
the result on the mailing list.

Thanks for doing that. I'll try to review the series soon.

Boris