Re: [PATCH] mtd: spi-nor: Fix SF MTDIDS when registering multiple MTDs with DM enabled

[Patrice CHOTARD <patrice.chotard@foss.st.com>]

Hi All

On 9/15/21 7:59 AM, Marek Vasut wrote:
> On 9/15/21 6:23 AM, Heiko Schocher wrote:
>> Hi Marek,
>>
>> On 15.09.21 01:06, Marek Vasut wrote:
>>> The flash->mtd.name used to be nor%d before, now it is the type of the
>>> SPI NOR like e.g. mt25ql02g. It is possible to find plenty of examples
>>> of the former in U-Boot configs by searching for MTDIDS.*nor.*spi, while
>>> the later is ambiguous if there are multiple flashes of the same type in
>>> the system and breaks existing environments.
>>>
>>> This does no longer get recognized when running 'mtdparts' for example:
>>> CONFIG_MTDIDS_DEFAULT="nor0=47040000.spi.0"
>>>
>>> Fix this by setting the correct mtd.name to nor%d.
>>>
>>> Fixes: b7f060565e3 ("mtd: spi-nor: allow registering multiple MTDs when DM is enabled")
>>> Signed-off-by: Marek Vasut <marex@denx.de>
>>> Cc: Heiko Schocher <hs@denx.de>
>>> Cc: Jagan Teki <jagan@amarulasolutions.com>
>>> Cc: Marek Behún <marek.behun@nic.cz>
>>> Cc: Miquel Raynal <miquel.raynal@bootlin.com>
>>> Cc: Pali Rohár <pali@kernel.org>
>>> Cc: Patrice Chotard <patrice.chotard@foss.st.com>
>>> Cc: Patrick Delaunay <patrick.delaunay@st.com>
>>> Cc: Priyanka Jain <priyanka.jain@nxp.com>
>>> Cc: Simon Glass <sjg@chromium.org>
>>> ---
>>>   drivers/mtd/spi/sf_mtd.c | 5 ++++-
>>>   1 file changed, 4 insertions(+), 1 deletion(-)
>>
>> Seem fixes the same problem as Patrick already posted here:
>>
>> https://patchwork.ozlabs.org/project/uboot/patch/20210913095742.v2.1.I73dae4b93f0587dc130e512e95a1f4794e0b0233@changeid/
>>
>> I find your approach cleaner, so:
>>
>> Acked-by: Heiko Schocher <hs@denx.de>
>>
>> @Patrick: Could you test this patch please?
> 
> The option from Patrick does look more predictable, but looking at the old implementation of spi_flash_mtd_number(), that one handled even cases of parallel-nor and spi-nor (both using the nor%d) present on the same system. This:
> 
>   static int spi_flash_mtd_number(void)
>   {
>   #ifdef CONFIG_SYS_MAX_FLASH_BANKS
>          return CONFIG_SYS_MAX_FLASH_BANKS;
>   #else
>          return 0;
>   #endif
>   }
>   ...
>   sprintf(sf_mtd_name, "nor%d", spi_flash_mtd_number());
> 
> The patch from Patrick does not, it does per-spi-nor-only counting using the dev_seq() there, which is more predictable, but local to spi-nor.
> 
> The MTD core has its own IDR counting, which is used by this patch and is global to the MTD core. That has two issues, one is that it is possibly too global and counts both nor%d and nand%d, which means it would fail on systems with both SPI NOR and regular NAND. The other is it is likely less predictable (what happens if the SPI NOR and parallel NOR gets probed in the reverse order ? I know it is unlikely, but it can happen in the future).
> 
> So I think we need a third option which I would suggest be based on the patch from Patrick, but which would take into account the other nor%d devices like parallel NOR flashes.
> 
> That would likely have to happen in the mtd core using some modified IDR counting. I think you might need to modify it such that you would pass in the prefix of the device (like 'nor') and then do per-prefix counting, with the special case that parallel NORs are counted first. Also, that would also have to consider probing of multiple SPI NORs in either order (say you have two, if you do 'sf probe 0:0 ; sf probe 0:1' vs. 'sf probe 0:1 ; sf probe 0:0'), and make sure they get enumerated with the same nor%d value either way, that might be where the dev_seq() would come in.

I just got a try with this patch and unfortunately, it doesn't solve the issue.
I tested it on STM32MP1-ev1 board which embedds 1 NAND and 2 SPI-NORs.
Here is the output of mtd list command:

U-Boot 2021.10-rc4-00001-g1923b5a21d (Sep 15 2021 - 10:48:48 +0200)

CPU: STM32MP157AAA Rev.B
Model: STMicroelectronics STM32MP157C eval daughter on eval mother
Board: stm32mp1 in basic mode (st,stm32mp157c-ev1)
Board: MB1263 Var1.0 Rev.C-01
DRAM:  1 GiB
Clocks:
- MPU : 650 MHz
- MCU : 208.878 MHz
- AXI : 266.500 MHz
- PER : 24 MHz
- DDR : 533 MHz
WDT:   Started with servicing (32s timeout)
NAND:  1024 MiB
MMC:   STM32 SD/MMC: 0, STM32 SD/MMC: 1
Loading Environment from MMC... *** Warning - bad CRC, using default environment

In:    serial
Out:   serial
Err:   serial
Net:   eth0: ethernet@5800a000
Hit any key to stop autoboot:  0 
STM32MP> mtd list
SF: Detected mx66l51235l with page size 256 Bytes, erase size 64 KiB, total 64 MiB
SF: Detected nor1 with page size 256 Bytes, erase size 64 KiB, total 64 MiB
List of MTD devices:
* nand0
  - type: NAND flash
  - block size: 0x40000 bytes
  - min I/O: 0x1000 bytes
  - OOB size: 224 bytes
  - OOB available: 118 bytes
  - ECC strength: 8 bits
  - ECC step size: 512 bytes
  - bitflip threshold: 6 bits
  - 0x000000000000-0x000040000000 : "nand0"
* nor2
  - device: mx66l51235l@0
  - parent: spi@58003000
  - driver: jedec_spi_nor
  - path: /soc/spi@58003000/mx66l51235l@0
  - type: NOR flash
  - block size: 0x10000 bytes
  - min I/O: 0x1 bytes
  - 0x000000000000-0x000004000000 : "nor2"
* nor2
  - device: mx66l51235l@1
  - parent: spi@58003000
  - driver: jedec_spi_nor
  - path: /soc/spi@58003000/mx66l51235l@1
  - type: NOR flash
  - block size: 0x10000 bytes
  - min I/O: 0x1 bytes
  - 0x000000000000-0x000004000000 : "nor2"


Patrice