On Thu, Jan 12, 2023 at 05:18:46PM -0800, Alan Previn wrote:
> From: Alexander Usyskin <alexander.usyskin@xxxxxxxxx>
>
> Add device link with i915 as consumer and mei_pxp as supplier
> to ensure proper ordering of power flows.
>
> V2: condition on absence of heci_pxp to filter out DG
>
> Signed-off-by: Alexander Usyskin <alexander.usyskin@xxxxxxxxx>
> Signed-off-by: Alan Previn <alan.previn.teres.alexis@xxxxxxxxx>
> ---
> drivers/gpu/drm/i915/pxp/intel_pxp_tee.c | 7 +++++++
> 1 file changed, 7 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp_tee.c b/drivers/gpu/drm/i915/pxp/intel_pxp_tee.c
> index d50354bfb993..bef6d7f8ac55 100644
> --- a/drivers/gpu/drm/i915/pxp/intel_pxp_tee.c
> +++ b/drivers/gpu/drm/i915/pxp/intel_pxp_tee.c
> @@ -127,6 +127,10 @@ static int i915_pxp_tee_component_bind(struct device *i915_kdev,
> intel_wakeref_t wakeref;
> int ret = 0;
>
> + if (!HAS_HECI_PXP(i915) &&
> + drm_WARN_ON(&i915->drm, !device_link_add(i915_kdev, tee_kdev,
I don't like the action here hidden behind the drm_WARN_ON.
Please notice that almost every use of this and other helpers like
this expect the param as a failure. Not an actual action. So,
most of lazy readers like me might ignore that the main function
is actually a param inside this warn condition.
We should probably stash the link as well...
pxp->dev_link = device_link_add(i915_kdev, tee_kdev,...);
so in the end below, instead of checking the HAS_HECI_PXP again
and use the remove version you check the dev_link and use the del
function.
something like:
if (pxp->dev_link)
device_link_del(pxp->dev_link);
Also, do you really need the WARN to see the stack when this happens
or you already know the callers?
Why not a simple drm_error msg?
if (!HAS_HECI_PXP(i915) {
pxp->dev_link = device_link_add(i915_kdev, tee_kdev,...);
if (!pxp->dev_link) {
drm_error();
return -ESOMETHING;
> DL_FLAG_STATELESS)))
do we need the RPM in sync as well?
I mean:
DL_FLAG_STATELESS | DL_FLAG_PM_RUNTIME)))
?
> + return -ENOMEM;
why ENOMEM?
> +
> mutex_lock(&pxp->tee_mutex);
> pxp->pxp_component = data;
> pxp->pxp_component->tee_dev = tee_kdev;
> @@ -169,6 +173,9 @@ static void i915_pxp_tee_component_unbind(struct device *i915_kdev,
> mutex_lock(&pxp->tee_mutex);
> pxp->pxp_component = NULL;
> mutex_unlock(&pxp->tee_mutex);
> +
> + if (!HAS_HECI_PXP(i915))
> + device_link_remove(i915_kdev, tee_kdev);
> }
>
> static const struct component_ops i915_pxp_tee_component_ops = {
> --
> 2.39.0
>
