spi_complete oops

Hello.
I develop driver to communicate to some chip via spi. Chip generate interrupts in which i run workqueue. Inside workqueue's handler i need to exchange data white chip again. Sometimes i got OOPS in spi_complete as args == NULL. What can be the reason of this? SPI message .complete and .context set up in __spy_sync call. I run kernel 3.1.5 on Variscite OM4460 board.

WBR,

Rumjantsev Egor