Re: [PATCH v9 08/10] gpu: host1x: mipi: Keep MIPI clock enabled and mutex locked till calibration done

[Dmitry Osipenko]

06.08.2020 22:01, Sowjanya Komatineni пишет:
...
> +int tegra_mipi_start_calibration(struct tegra_mipi_device *device)
>  {
>  	const struct tegra_mipi_soc *soc = device->mipi->soc;
>  	unsigned int i;
> @@ -381,12 +375,16 @@ int tegra_mipi_calibrate(struct tegra_mipi_device *device)
>  	value |= MIPI_CAL_CTRL_START;
>  	tegra_mipi_writel(device->mipi, value, MIPI_CAL_CTRL);
>  
> -	mutex_unlock(&device->mipi->lock);
> -	clk_disable(device->mipi->clk);
> +	/*
> +	 * Wait for min 72uS to let calibration logic finish calibration
> +	 * sequence codes before waiting for pads idle state to apply the
> +	 * results.
> +	 */
> +	usleep_range(75, 80);

Could you please explain why the ACTIVE bit can't be polled instead of
using the fixed delay? Doesn't ACTIVE bit represents the state of the
busy FSM?