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Altera_Forum
Honored Contributor I
753 Views

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"
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2 Replies
Altera_Forum
Honored Contributor I
40 Views

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
Altera_Forum
Honored Contributor I
40 Views

I get it. Thank you, Michael.

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