[U-Boot] [PATCH v2 0/2] OMAP/GPMC: speed up NAND read access

[Daniel Mack]

Hi,

On 06/26/2014 08:08 AM, Gupta, Pekon wrote:
>> From: Daniel Mack [mailto:zonque at gmail.com]
>>
>> Resending this since I got no replies on the first version.
>> I also fixed up the commit log of #1.
>>
> I plan to test this, but there is still a long pending list of patches which
> for me to test in kernel and u-boot. So it might take bit time.
> But really thanks much for this feature addition.
> 
> Just a minor feedback, if you like it...
> GPMC controller support various transfer modes
> - POLLED: <default mode>
> - PREFETCH_POLLED : <as added in this patch>
> - PREFETCH_IRQ: <not implemented/required>
> - PREFETCH_DMA: <not implemented/required>
> 
> (1) Will it be okay to use following config names, this would be synonymous
> to the xfer-modes DT binding used in kernel ?
> CONFIG_NAND_OMAP_XFER_MODE_POLLED
> CONFIG_NAND_OMAP_XFER_MODE_PREFETCH_POLLED

Yes, I've seen that, but decided for shorter names as we will never
support DMA or IRQ modes from U-Boot. But I can of course change that,
I'd ultimately leave such decisions up to you :)

> (2) It would be good if you can make "PREFETCH_POLLED" mode as "default"
> And instead make "POLLED" mode selectable.
> #ifdef CONFIG_NAND_OMAP_XFER_MODE_POLLED
> 	/* old behavior */
> #else  /* 
> 	/* default PREFETCH_POLLED mode */
> #endif

Ok, but then we'd need something that selects PREFETCH_POLLED
automatically if nothing else is selected in the config. I wanted to
avoid yet another mandatory config symbol that have to be patched into
all existing configs. Could you lay out how that would be done?

> However, let me first test your patch, and these minor nit-picks
> (if required) can be done later.

Alright. I'm in no hurry with this. Good to know it's on your list.


Thanks,
Daniel