I am trying to interface a ST7796 display to STM32H747XI DISCO board. The display vendor recommended setting the DSI LPMODE clock to 5MHz.How do I accomplish this?

[Tesla DeLorean]

I'd suppose you'd have to change the PLL, LTDC or DSI clock settings when you enter Low Power mode. Id expect them to stop in STANDBY

[MM..1]

Open CubeMX wizard Clock config and locate DSI CLK