Hi Laurent,
> -----Original Message-----
> From: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
> Sent: Monday, September 30, 2024 3:22 PM
> To: G.N. Zhou (OSS) <guoniu.zhou@xxxxxxxxxxx>
> Cc: rmfrfs@xxxxxxxxx; martink@xxxxxxxxx; kernel@xxxxxxx;
> mchehab@xxxxxxxxxx; shawnguo@xxxxxxxxxx; s.hauer@xxxxxxxxxxxxxx;
> kernel@xxxxxxxxxxxxxx; festevam@xxxxxxxxx; imx@xxxxxxxxxxxxxxx; linux-
> media@xxxxxxxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; linux-
> kernel@xxxxxxxxxxxxxxx
> Subject: Re: [PATCH 0/3] media: imx8mq-mipi-csi2: Simplify power management
> handling
>
> On Mon, Sep 30, 2024 at 07:08:09AM +0000, G.N. Zhou (OSS) wrote:
> > On Sunday, September 29, 2024 9:44 PM, Laurent Pinchart wrote:
> > >
> > > Hello,
> > >
> > > This small patch series is a reaction to "[PATCH] media: nxp:
> > > imx8mq-mipi-csi2: Fix CSI clocks always enabled issue" ([1]).
> > > Instead of making the PM handling more complex, I think it can be greatly
> simplified.
> > >
> > > I have only compile-tested the patches. Guoniu, could you give this a try ?
> >
> > After applying the patches and test both on iMX8ULP.
> >
> > For iMX8ULP, it will cause kernel dump when access CSI registers and
> > system hang during do suspend/resume while streaming Need to add
> > system suspend/resume handlers and call
> > pm_runtime_force_suspend/resume in the handlers.
> >
> > I tried to debug this issue and found pm runtime callback won't be
> > called when system resume. The state of power domain won't enabled.
>
> Thank you for testing.
>
> I wonder if this could be caused by the CSI bridge being resumed from system
> sleep before the CSI-2 receiver. Could you check if that's the case ? If so, does the
> following change fix the issue ?
I tested on iMX8ULP which don't use CSI bridge but ISI, not iMX8MQ. In ISI driver, I notice that
it already handler the device relationship when subdev bound like bellow:
link = device_link_add(isi->dev, sd->dev, DL_FLAG_STATELESS);
if (!link) {
dev_err(isi->dev,
"Failed to create device link to source %s\n", sd->name);
return -EINVAL;
}
For iMX8MQ, I'm trying to enable it, but meet some problems, so can't give you the results in short time.
>
> diff --git a/drivers/media/platform/nxp/imx7-media-csi.c
> b/drivers/media/platform/nxp/imx7-media-csi.c
> index 9566ff738818..c66b0621e395 100644
> --- a/drivers/media/platform/nxp/imx7-media-csi.c
> +++ b/drivers/media/platform/nxp/imx7-media-csi.c
> @@ -2057,9 +2057,22 @@ static int imx7_csi_notify_bound(struct
> v4l2_async_notifier *notifier, {
> struct imx7_csi *csi = imx7_csi_notifier_to_dev(notifier);
> struct media_pad *sink = &csi->sd.entity.pads[IMX7_CSI_PAD_SINK];
> + struct device_link *link;
>
> csi->src_sd = sd;
>
> + /*
> + * Enforce suspend/resume ordering between the source (supplier) and
> + * the CSI (consumer). The source will be suspended before and resume
> + * after the CSI.
> + */
> + link = device_link_add(csi->dev, sd->dev, DL_FLAG_STATELESS);
> + if (!link) {
> + dev_err(csi->dev,
> + "Failed to create device link to source %s\n", sd->name);
> + return -EINVAL;
> + }
> +
> return v4l2_create_fwnode_links_to_pad(sd, sink,
> MEDIA_LNK_FL_ENABLED |
> MEDIA_LNK_FL_IMMUTABLE);
> }
>
> > > [1]
> > > https://lore.kernel.org/r/20240929101635.1648234-1-guoniu.zhou@oss.n
> > > xp.com
> > >
> > > Laurent Pinchart (3):
> > > media: imx8mq-mipi-csi2: Drop stream stop/restart at suspend/resume
> > > time
> > > media: imx8mq-mipi-csi2: Drop ST_SUSPENDED guard
> > > media: imx8mq-mipi-csi2: Drop system suspend/resume handlers
> > >
> > > drivers/media/platform/nxp/imx8mq-mipi-csi2.c | 113
> > > ++----------------
> > > 1 file changed, 10 insertions(+), 103 deletions(-)
> > >
> > >
> > > base-commit: 81ee62e8d09ee3c7107d11c8bbfd64073ab601ad
>
> --
> Regards,
>
> Laurent Pinchart
