[U-Boot] [RFC PATCH 17/20] cmd: mtd: add 'mtd' command

[Miquel Raynal]

Hi Stefan,

Stefan Roese <sr at denx.de> wrote on Fri, 6 Jul 2018 15:21:20 +0200:

> Hi Miquel,
> 
> On 06.07.2018 14:26, Miquel Raynal wrote:
> > Jagan Teki <jagannadh.teki at gmail.com> wrote on Fri, 6 Jul 2018 17:08:57
> > +0530:  
> > >> On Wed, Jun 6, 2018 at 9:00 PM, Miquel Raynal <miquel.raynal at bootlin.com> wrote:
> >>> There should not be a 'nand' command, a 'sf' command and certainly not
> >>> another 'spi-nand'. Write a 'mtd' command instead to manage all MTD
> >>> devices at once. This should be the preferred way to access any MTD
> >>> device.  
> >>
> >> So are you planning to integrate sf, nand command in future, adding
> >> them dm conversion of many stuff. I would like to reommend to go with
> >> spinand command. I have been through this and finally added spinor
> >> command, which I will going to in soon. once all are converted to dm,
> >> it would be easy and meaningfull to have common command.
> > > I'm not sure we are in sync about this. The whole point of the previous  
> > discussion was to decide whether or not we should make full use of
> > the MTD stack or not. I think it was pretty clear on the fact that
> > people prefer to be close to Linux's architecture on this regard.  
> > > MTD being an abstraction of the type of memory, I don't get the  
> > point in creating yet another command each time a new type of
> > device is supported. The fact that all the drivers of these devices
> > register to the MTD layer makes it trivial to interact with. So why
> > should we wait?  
> 
> Yes, please don't add new commands for each subsystem / device-type.
> I like the idea of adding one new command-set (your mtd command) and
> extending this one to all other device-types over the time.
> 
> BTW: I'm testing your SPI NAND patches right now (still struggling
> with some Gigadevice SPI NAND) and found that the "mtd" command is
> not really in-line with the usual U-Boot commands. Here some
> comments:
> 
> - Use hex values per default (addresses, sizes and soffset)
> - "mtd read" just prints the read values. It makes more sense
>    to read into memory instead (similar to the "mtd write")

I absolutely agree with this! I sent this series to show people what I
planned to contribute but this mtd command is still a WIP and there are
plenty of things to address.

> 
> I have some patches to address these issues in the queue (still
> need some massaging), which you can fold into your patchset, once
> we agree on this.

I am currently working on a new iteration of this series in which the
mtd.c file will change quite a bit. I plan to send a new version early
next week. I suppose this one will be much more stable to base your
fixes/enhancements on.

Thanks,
Miquèl