Help with writing to micro SD card

Help with writing to micro SD card

[Larry Finger]

I am helping to get wifi and Bluetooth woring under Linux using a Winbook TW100 
tablet. The main goal is working quite well; however, I am only able to run 
using Live media. Whenever I try to load Linux onto either the internal SD card, 
or one mounted in the external slot, the process stalls with nothing logged.

I know the external card is OK as I can read or write it when it is mounted in 
my laptop.

When I received the tablet, I used dd to back up the internal card. When I used 
a block size of 4M in that operation, it also froze; however, the standard block 
size (512) worked. That suggests that the standard Linux r/w operations on the 
device are too fast.

What should I do to get some debug information? If my idea is correct, how might 
I slow down the I/O to the device?

Thanks,

Larry

Re: Help with writing to micro SD card

[One Thousand Gnomes]

> When I received the tablet, I used dd to back up the internal card. When I used 
> a block size of 4M in that operation, it also froze; however, the standard block 
> size (512) worked. That suggests that the standard Linux r/w operations on the 
> device are too fast.

Unlikely.

> What should I do to get some debug information?

As its Baytrail-T make sure you have

- Current BIOS
- Latest kernel

If it persists try disabling power management on the SD card interface.
It may be worth reading through the ASUS T100TA bug reports and
workarounds as that is probably the most poked at platform for BYT/T


Alan