cmdlineparts and chip initialization order

With a command line like this:

console=ttyAM0 root=/dev/hda1 mtdparts=norflash:2m(boot),-(root);nandflash:32k(apex)ro,-(root)

I am able to initialization partitions for the NOR flash, but not the NAND flash. It look like the problem is that the NOR flash driver is initializing before the mtdparts command line parsed, but the NAND flash isn't.

All code is linked into the kernel--no modules.

Moving the cmdlinepart.o file to the end of the list appears to prevent the command line from being parsed.

Is this a recognized problem with a known solution.

BTW, it looks like none of the other NAND drivers expect a command line partition setup. Has anyone else tried?

Cheers.

The commandline parition code must be registered as a partition parser before any mapping driver is initialized. So it's not surprising that it does not work when it is linked in last, as the init functions are called in link order

It has nothing to do with NOR or NAND. The driver calls a parition parser.

Provide more detailed information, please. Switch on MTD debugging and add some MTD_DEBUG in the relevant places.

tglx

In this dmesg dump, you can see that the CMDLINE-PART stuff occurs before the NAND driver is initialized and after the NOR driver. I am assuming that this is the reason that the nand driver doesn't receive partitions. Is this not the case?

lpd79524 flash device: 1000000 at 44000000
lpd79524_norflash: Found 1 x16 devices at 0x0 in 16-bit bank
lpd79524_norflash: Found 1 x16 devices at 0x800000 in 16-bit bank
Intel/Sharp Extended Query Table at 0x0031
cfi_cmdset_0001: Erase suspend on write enabled
Using buffer write method
DEBUG-CMDLINE-PART: parse_cmdline_partitions top
DEBUG-CMDLINE-PART: parsing <2m(boot),-(root);lpd79524_nandflash:32k(apex)ro,-(>
DEBUG-CMDLINE-PART: partition 1: name <root>, offset 0, size ffffffff, mask fla0
DEBUG-CMDLINE-PART: partition 0: name <boot>, offset 0, size 200000, mask flags0
DEBUG-CMDLINE-PART: mtdid=<lpd79524_norflash> num_parts=<2>
DEBUG-CMDLINE-PART: parsing <32k(apex)ro,-(root)>
DEBUG-CMDLINE-PART: partition 1: name <root>, offset 0, size ffffffff, mask fla0
DEBUG-CMDLINE-PART: partition 0: name <apex>, offset 0, size 8000, mask flags 3
DEBUG-CMDLINE-PART: mtdid=<lpd79524_nandflash> num_parts=<2>
2 cmdlinepart partitions found on MTD device lpd79524_norflash Creating 2 MTD partitions on "lpd79524_norflash":
0x00000000-0x00200000 : "boot"
mtd: Giving out device 0 to boot
0x00200000-0x01000000 : "root"
mtd: Giving out device 1 to root
NAND device: Manufacturer ID: 0x98, Chip ID: 0x75 (Toshiba NAND 32MiB 3,3V 8-bi) Scanning device for bad blocks
mtd: Giving out device 2 to lpd79524_nandflash

I now understand why the partitions weren't being parsed. I didn't realize that the driver itself was responsible for calling the code that parses partitions.

Cheers.

I recently had to do this and had the same problem. I took a look at the low level driver code for my particular processor and noted that not all MTD drivers had partition parsing code.

e.g in at91_dataflash.c there is parser related code:

int parse_cmdline_partitions(struct mtd_info *master,

                struct mtd_partition **pparts, const char *mtd_id);

and ...

#ifdef CONFIG_MTD_CMDLINE_PARTS
        char mtdID[14];

#endif

and ...

#ifdef CONFIG_MTD_CMDLINE_PARTS
        sprintf(mtdID, "dataflash%i", nr_devices-1);
        mtd_parts_nr = parse_cmdline_partitions(device, &mtd_parts, mtdID);

#endif

This parsing code is missing from at91_nand.c, and that's why I wasn't able to setup my NAND partitions from the command line (previous posting).

regards,

Aras