Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/stm32/stm32f7/STM32F767/DSI/DSI_GPSR#0x0
DSI Host Generic Packet Status Register
Command FIFO Empty
Command FIFO Full
Payload Write FIFO Empty
Payload Write FIFO Full
Payload Read FIFO Empty
Payload Read FIFO Full
Read Command Busy
https://github.com/modm-io/cmsis-svd-stm32