[U-Boot] fsl_elbc_nand bug

[Scott Wood]

On Fri, 2015-05-15 at 14:48 -0700, Andrei Yakimov wrote:
> Hi, 
>  I just found, if NAND ONFI parameter page first copy is 
> bad, u-boot will never read extra copes: 
> 
> fsl_elbc_nand.c: 
>  342                 out_be32(&lbc->fbcr, 256);  
>  343                 ctrl->read_bytes = 256;
> 
> this code cause "read beyond buffer" error message:
>  
> nand_base.c:
>    chip->cmdfunc(mtd, NAND_CMD_PARAM, 0, -1);
> 3243         for (i = 0; i < 3; i++) {
> 3244                 for (j = 0; j < sizeof(*p); j++)
> 3245                         ((uint8_t *)p)[j] = chip->read_byte(mtd);
> 3246                 if (onfi_crc16(ONFI_CRC_BASE, (uint8_t *)p, 254) ==
> 3247                                 le16_to_cpu(p->crc)) {
> 3248                         break;
> 3249                 }
> 3250         }
> 
> Unfortunately I do not working with latest u-boot now,
> so can not provide a patch,  read size should be increased to
> at least 768 ( 3 copy mandatory for ONFI spec). Linux kernel should be
> updated too.

Could you send a patch (both here and Linux)?  Especially since you have
a test case. :-)

Though a better fix than just increasing the byte count would be to add
a read_id() callback so that the NAND subsystem can actually tell the
driver how much data it's expecting, rather than forcing it to go
through cmdfunc that makes high-level drivers (poorly) emulate
low-level hardware.

> I am also not expert for other NAND controllers drivers.

At least IFC will have the same issue.

-Scott