Write to SD card fails
I am using Sandisk 2GB micro SD card on ARM processor EP9307A.
The card is detected , mounted.
I can read data from the SD card.
But cannot write to it.
There is no error when I attempt to write to the Card.It appears as if its working fine.But after umount and re-mount , the data written is gone.
Here is the log when the SD card is detected:
# insmod drv
card size = 1977614336, sector size = 31, wp_grp_size = 127, wp_grp_enable = y
What is the significance of Write Group Protect Enable (wp_grp_enable=y).
Is it the case that the SD card is write protected.
Using CMD9 : SEND_CSD , I can read the Card Specific Data (CSD).
I have tried CMD27 : PROGRAM_CSD , to CLEAR wr_grp_enable : No effect seen.
I have tried CMD29 : CLEAR_WRITE_PROT ,: No effect seen.
Where is the issue,
1. I could not send commands properly.
2. Card cannot be set free from WRITE_PROTECT.
3. Some thing else