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Altera_Forum's avatar
Altera_Forum
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14 years ago

mmc/sd problem

Hi all,

I have generated a uclinux kernel for my custom board. The SD card driver is bast on SPI bus, with 20MHz bus clock. (According to http://www.alterawiki.com/wiki/mmcsd).

I can operate the SD card well after I mount it to /mnt. However, I met a problem. If I umount the SD card, and pop-push it, a Error will come out. I list it at the tail of this thread.

The case remains even if I change the SPI bus clock to 100KHz. Could somebody help me, please...

Derek

"mmcblk0: retrying using single block read

mmcblk0: error -110 sending status comand<3>mmcblk0: error -110 sending read/wri

te command, response 0x0, card status 0x0

end_request: I/O error, dev mmcblk0, sector 103

mmcblk0: error -110 sending status comand<3>mmcblk0: error -110 sending read/wri

te command, response 0x0, card status 0x0

end_request: I/O error, dev mmcblk0, sector 104

EXT3-fs: unable to read superblock

mmcblk0: error -110 sending status comand<3>mmcblk0: error -110 sending read/wri

te command, response 0x0, card status 0x0

end_request: I/O error, dev mmcblk0, sector 101

FAT: unable to read boot sector

mount: mounting /dev/mmcblk0p1 on /mnt failed: Input/output error"

2 Replies

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    14 years ago

    Supposedly the driver is not notified by the hardware that the card has been unpowered and needs re-initialization. e.g. the NEEK lacks the appropriate hardware for this. I suppose a dedicated i/O is necessary on that behalf.

    When playing with the SD-Card I needed to unload and re-load the driver to re-initialize a re-inserted card.

    -Michael