Re: [PATCH v8 08/10] gpu: host1x: mipi: Keep MIPI clock enabled till calibration is done

From: Dmitry Osipenko
Date: Wed Aug 05 2020 - 13:40:14 EST


05.08.2020 20:29, Sowjanya Komatineni пишет:
...
> UART_FST_MIPI_CAL is the clock used for calibration logic which is FSM
> that goes thru sequence codes and when done waits for pads to be in
> LP-11 to apply results.
>
> MIPI_CLK is controller gate clock which is also need to be kept enabled
> as incase if it sees LP-11 it updates registers so its recommended to
> have this clock enabled.
>
> We can cancel_calibration() in CSI only when csi/sensor stream on fails
> and in which case there will be no LP-11 so we can unconditionally
> disable MIPI_CLK.
>

There is no guarantee that the fail comes before the LP-11. For example,
some odd camera driver may have a complicated enable sequence which may
fail after enabling the hardware streaming.