Quoting Saravana Kannan (2021-10-07 18:10:24) > On Thu, Oct 7, 2021 at 1:11 PM Stephen Boyd <swboyd@xxxxxxxxxxxx> wrote: > > > > Quoting Stephen Boyd (2021-10-07 11:40:07) > > > Quoting Saravana Kannan (2021-10-06 20:07:11) > > > > On Wed, Oct 6, 2021 at 12:38 PM Stephen Boyd <swboyd@xxxxxxxxxxxx> wrote: > > > > > diff --git a/drivers/base/component.c b/drivers/base/component.c > > > > > index 0a41bbe14981..d99e99cabb99 100644 > > > > > --- a/drivers/base/component.c > > > > > +++ b/drivers/base/component.c > > > [...] > > > > > + continue; > > > > > + > > > > > + /* Matches put in component_del() */ > > > > > + get_device(&adev->dev); > > > > > + c->link = device_link_add(&adev->dev, c->dev, > > > > > + DL_FLAG_STATELESS | DL_FLAG_PM_RUNTIME); > > > > > > > > Remove the STATELESS flag and you'll get a bunch of other stuff done for free: > > > > > > I tried that and it didn't work for me. The aggregate device never > > > probed and I was left with no display. Let me see if I can reproduce it > > > with logging to provide more details. > > > > This patch fixes it (whitespace damaged sorry). > > Not sure why you have to trigger an explicit rescan, but instead of > this patch below, you could also try setting this flag instead? > DL_FLAG_AUTOPROBE_CONSUMER > I'd rather not conflate component driver probe with component_add() being called. It's simpler if that is the case, i.e. all component drivers are calling component_add() in their driver probe routine, but I don't know if that's always true. I did this poor audit of the kernel $ git grep -p \[^_]component_add | grep \.c= | grep -v probe drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c=static int amdgpu_dm_audio_init(struct amdgpu_device *adev) drivers/gpu/drm/i915/display/intel_audio.c=static void i915_audio_component_init(struct drm_i915_private *dev_priv) drivers/gpu/drm/i915/display/intel_hdcp.c=void intel_hdcp_component_init(struct drm_i915_private *dev_priv) drivers/gpu/drm/nouveau/dispnv50/disp.c=nv50_audio_component_init(struct nouveau_drm *drm) drivers/gpu/drm/rockchip/dw-mipi-dsi-rockchip.c=static int dw_mipi_dsi_rockchip_host_attach(void *priv_data, drivers/gpu/drm/rockchip/dw-mipi-dsi-rockchip.c=static int dw_mipi_dsi_dphy_init(struct phy *phy) drivers/gpu/drm/vc4/vc4_dsi.c=static int vc4_dsi_host_attach(struct mipi_dsi_host *host, and then peeking at rockchip above I see that component_add() is called in the mipi dsi attach ops and then I got lost trying to figure out where it ends up. Maybe it is still in some probe call? Anyway, I think we still have to do a rescan so that we can try to bind the aggregate device. Is there a better API to use for that?
