[U-Boot] [PATCH] cmd: mtd: solve bad block support in erase command

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

Hi Patrick,

Patrick DELAUNAY <patrick.delaunay@st.com> wrote on Thu, 26 Sep 2019
09:31:46 +0000:

> Hi Stefan,
> 
> > From: Stefan Roese <sr@denx.de>
> > Sent: vendredi 20 septembre 2019 11:20
> > 
> > Hi Patrick,
> > 
> > On 20.09.19 09:20, Patrick Delaunay wrote:  
> > > This patch modify the loop in mtd erase command to erase one by one
> > > the blocks in the requested area.
> > >
> > > It solves issue on "mtd erase" command on nand with existing bad
> > > block, the command is interrupted on the first bad block with the trace:
> > > 	"Skipping bad block at 0xffffffffffffffff"
> > >
> > > In MTD driver (nand/raw), when a bad block is present on the MTD
> > > device, the erase_op.fail_addr is not updated and we have the initial
> > > value MTD_FAIL_ADDR_UNKNOWN = (ULL)-1.  
> > 
> > So here is the difference? I remember testing this on a board with SPI NAND and
> > here it worked correctly. But your test case is with RAW NAND?  
> 
> Yes with RAW nand.
> 
> it is the difference the U-Boot code, for SPI nan use:
> 	int nanddev_mtd_erase()
> 
> the fail address is always updated 
> 	=> einfo->fail_addr = nanddev_pos_to_offs(nand, &pos);  
> 
>  
> > Do you have a change to also test this on a board with SPI NAND?  
> 
> I do the test  a SPI-NAND today.
> 
> The mtd erase command was functional on SPI-ANND before my patch : 
> I create 2 bad block manually and they are correctly skipped.
> 
> STM32MP> mtd list    
> List of MTD devices:
> * spi-nand0
>   - device: spi-nand at 0
>   - parent: qspi at 58003000
>   - driver: spi_nand
>   - type: NAND flash
>   - block size: 0x20000 bytes
>   - min I/O: 0x800 bytes
>   - OOB size: 128 bytes
>   - OOB available: 62 bytes
>   - 0x000000000000-0x000010000000 : "spi-nand0"
> 	  - 0x000000000000-0x000000200000 : "fsbl"
> 	  - 0x000000200000-0x000000400000 : "ssbl1"
> 	  - 0x000000400000-0x000000600000 : "ssbl2"
> 	  - 0x000000600000-0x000010000000 : "UBI"
> 
> STM32MP> mtd erase spi-nand0 0x00000000 0x10000000              
> Erasing 0x00000000 ... 0x0fffffff (2048 eraseblock(s))
> 0x0fd00000: bad block
> 0x0fd20000: bad block
> attempt to erase a bad/reserved block @fd00000
> Skipping bad block at 0x0fd00000
> attempt to erase a bad/reserved block @fd20000
> Skipping bad block at 0x0fd20000
> 0x0fd00000: bad block
> 0x0fd20000: bad block
> 
> 
> > Thanks,
> > Stefan
> >   
> 
> What it is the better solution for you ?
> 
>  update the MTD command (my patch) or allign the behavior of the 2 MTD devices 
> - MTD RAW NAND (nand_base.c:: nand_erase_nand)
> - MTD SPI NAND (core.c:: nanddev_mtd_erase)

Do you think it is easy to make use of nanddev_mtd_erase() from the raw
NAND core? It is probably a little bit more elegant (and efficient)
to do all in one go than iterating over each block (while there is a
helper in the core to do that).


Thanks,
Miquèl