[U-Boot] [PATCH v7 11/13] cmd: mtdparts: try to probe the MTD devices as a fallback

[Miquel Raynal <miquel.raynal@bootlin.com>]

Hi Stefan,

Stefan Roese <sr@denx.de> wrote on Sat, 1 Sep 2018 11:02:43 +0200:

> On 31.08.2018 16:57, Miquel Raynal wrote:
> > Current implementation of mtdparts command errors out if the desired MTD
> > device is not found. Fallback to the new probe function in this case
> > before erroring out.  
> > > This will the save the user the need to call something like 'mtd list'  
> > before mtdparts.  
> > > Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>  
> > Acked-by: Jagan Teki <jagan@openedev.com>
> > ---
> >   cmd/mtdparts.c | 16 +++++++++++++---
> >   1 file changed, 13 insertions(+), 3 deletions(-)  
> > > diff --git a/cmd/mtdparts.c b/cmd/mtdparts.c  
> > index f7ed1a0779..a1102c3fc5 100644
> > --- a/cmd/mtdparts.c
> > +++ b/cmd/mtdparts.c
> > @@ -79,6 +79,10 @@
> >   #include <linux/err.h>
> >   #include <linux/mtd/mtd.h>  
> >   > +#if defined(CONFIG_MTD)  
> > +#include <mtd.h>
> > +#endif
> > +
> >   #if defined(CONFIG_CMD_NAND)
> >   #include <linux/mtd/rawnand.h>
> >   #include <nand.h>
> > @@ -307,9 +311,15 @@ static int get_mtd_info(u8 type, u8 num, struct mtd_info **mtd)  
> >   >   	sprintf(mtd_dev, "%s%d", MTD_DEV_TYPE(type), num);  
> >   	*mtd = get_mtd_device_nm(mtd_dev);
> > -	if (IS_ERR(*mtd)) {
> > -		printf("Device %s not found!\n", mtd_dev);
> > -		return 1;
> > +	if (IS_ERR_OR_NULL(*mtd)) {
> > +#ifdef CONFIG_MTD
> > +		mtd_probe_devices();
> > +		*mtd = get_mtd_device_nm(mtd_dev);
> > +#endif
> > +		if (IS_ERR_OR_NULL(*mtd)) {
> > +			printf("Device %s not found!\n", mtd_dev);
> > +			return 1;
> > +		}
> >   	}
> >   	put_mtd_device(*mtd);  
> >   >   
> This is most likely the use case for CMD_MTD without MTD, correct?

Not exactly, I think the use case you were looking for is explained in
my previous answer and this #ifdef stands for the opposite situation,
where someone using the 'legacy' commands wants to interact with
devices with DM compliant drivers: the MTD device won't be registered
before (and thus, not accessible) the mtd_probe_device() call.

For other devices the use will have to probe manually the device, eg.
for SPI-NOR: 'sf probe 0'.

> 
> Reviewed-by: Stefan Roese <sr@denx.de>
> 
> Thanks,
> Stefan


Thanks,
Miquèl