RB3 Slow Host Issue: SPI Write/Read Operation taking more time than expected

Hi,
During run time few issues observed at RB3.
1.SPI write and read operations got delayed
2.Our SPI Wrapper driver invoking core SPI APIs spi_write() and spi_sync_transfer for Write and read operations.
3.But observed some random delay(~9ms) between core API’s invoked and actual data transmission over SPI lines.
4.But same behavior is not observed in Hikey960 board
5.Is there any way to increase the performance or optimize this?
Corresponding saleae log SPI traces attached here for reference.

@danielt @Loic Any idea on this issue?