Hi Guoniu,
Thank you for the patch.
On Sun, Sep 29, 2024 at 06:16:35PM +0800, guoniu.zhou@xxxxxxxxxxx wrote:
> From: "Guoniu.zhou" <guoniu.zhou@xxxxxxx>
>
> Fix CSI clocks always enabled issue after run system suspend/resume.
>
> The clocks for CSI will be enabled in imx8mq_mipi_csi_pm_resume()
> when system resume and the state of CSI will be set to ST_POWERED.
> It not only cause clock always enabled issue but also system hang
> issue on iMX8ULP platform since imx8mq_mipi_csi_pm_suspend() will
> access CSI registers if run system suspend/resume again, but the
> CSI power domain is not active.
>
> In order to fix this issue, using pm_runtime_force_suspend/resume
> instead of calling imx8mq_mipi_csi_pm_suspend/resume directly.
I think you can simplify suspend/resume handling in the driver by
dropping the system suspend/resume handlers. At system suspend time the
device should already be stopped, because the top-level driver (the CSI
bridge in the i.MX8MQ) should have stopped the pipeline. Similarly, at
system resume time, there should be no need to restart streaming, as the
top-level driver will control that.
I'll send a patch and CC you, could you give it a try ?
> Signed-off-by: Guoniu.zhou <guoniu.zhou@xxxxxxx>
> ---
> drivers/media/platform/nxp/imx8mq-mipi-csi2.c | 7 +++++--
> 1 file changed, 5 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/media/platform/nxp/imx8mq-mipi-csi2.c b/drivers/media/platform/nxp/imx8mq-mipi-csi2.c
> index d4a6c5532969..15029bb81b35 100644
> --- a/drivers/media/platform/nxp/imx8mq-mipi-csi2.c
> +++ b/drivers/media/platform/nxp/imx8mq-mipi-csi2.c
> @@ -697,8 +697,11 @@ static int imx8mq_mipi_csi_suspend(struct device *dev)
> {
> struct v4l2_subdev *sd = dev_get_drvdata(dev);
> struct csi_state *state = mipi_sd_to_csi2_state(sd);
> + int ret;
>
> - imx8mq_mipi_csi_pm_suspend(dev);
> + ret = pm_runtime_force_suspend(dev);
> + if (ret < 0)
> + return ret;
>
> state->state |= ST_SUSPENDED;
>
> @@ -713,7 +716,7 @@ static int imx8mq_mipi_csi_resume(struct device *dev)
> if (!(state->state & ST_SUSPENDED))
> return 0;
>
> - return imx8mq_mipi_csi_pm_resume(dev);
> + return pm_runtime_force_resume(dev);
> }
>
> static int imx8mq_mipi_csi_runtime_suspend(struct device *dev)
--
Regards,
Laurent Pinchart
