MMC/SD cards hotplug scenario

["Madhusudhan Chikkature Rajashekar" <madhu.cr@ti.com>]

Hi Pierre/All,

I have a query regarding one of the MMC/SD cards hotplug use case scenario and its expected behavior.

In the case where the MMC/SD card is removed physically from the slot during an active data transfer happening on the card, I notice
lot of
I/O errors being generated. The numbers of I/O errors seem to depend on the size of the file being copied(the errors semm to be a
mixture of FS + MMC core errors). After the end of the I/O errors I can umount the partition that was mounted and I reinsert the
card. It seem not to work very well consistently. I mean some times the card removal/insertion does seem to work that well. Whereas
card insertion/removal works perfectly fine if tested when no data transfer is happening.

Does MMC/SD core need to handle some things to support this scenario? Does MMC/SD core handle this scenario gracefully? Has anyone
tried something similar before?

As far as I understand this type of scenario can not be handled well in the controller drivers alone. Am I missing something here?

Regards,
Madhu