tech-kern archive

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Old Index]

1024bytes/sect microSD support

Hi! all,

I has 2 problems with sdmmc and pxamci.

I got a microSD.  My GUMSTIX reports this message with it.

  ld0: 1938 MB, 984 cyl, 32 head, 63 sec, 1024 bytes/sect x 1985024 sectors

It is 1024 bytes/sect card.  I can't mount, fdisk, and disklabel it.
This reason is report 'read CRC error'(STAT_CRC_READ_ERROR and MMC_I_DAT_ERR)
by pxamci.
I try with following fix.  pxamci quit and work.  ;-) 

sys/arch/arm/xscale/pxa2x0_mci.c:pxamci_attach_sub() ---
        /* Setup max block length */
        if (CPU_IS_PXA270) {
#if 0
                sc->sc_maxblklen = 2048;
                sc->sc_maxblklen = 512;
        } else {
                sc->sc_maxblklen = 512;
--- sys/arch/arm/xscale/pxa2x0_mci.c::pxamci_attach_sub()

Also I know, Linux's drivers/mmc/card/block.c always set 512bytes.

         * Both SD and MMC specifications state (although a bit
         * unclearly in the MMC case) that a block size of 512
         * bytes must always be supported by the card.
        md->block_bits = 9;

I think that it is necessary to always adjust us to 512 bytes.  If this
is not supported, we cannot have Linux and interchangeability.
However, I do not know how to set more better it.  Does anyone have an


Home | Main Index | Thread Index | Old Index