On Wed, 17 Aug 2022, "Lisovskiy, Stanislav" <stanislav.lisovskiy@xxxxxxxxx> wrote: > On Tue, Aug 16, 2022 at 06:37:20PM +0300, Jani Nikula wrote: >> Avoid using ports that aren't initialized in case the VBT backlight or >> CABC ports have invalid values. This fixes a NULL pointer dereference of >> intel_dsi->dsi_hosts[port] in such cases. >> >> Cc: stable@xxxxxxxxxxxxxxx >> Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx> > > Would be interesting to figure out which one of those actually fixed the > https://gitlab.freedesktop.org/drm/intel/-/issues/6476 issue, this one > or next one. I asked to test with patch 1 alone first, and it lets them boot without the oops. And it produces the warn added here. But this just filters port C out of bl_ports, and doesn't fix the root cause. Patch 2 should fix the root cause, get rid of the warn and give them functioning backlight. I hope. There was no test results with patches 2&3. :) > Reviewed-by: Stanislav Lisovskiy <stanislav.lisovskiy@xxxxxxxxx> Thanks for the review! BR, Jani. > >> --- >> drivers/gpu/drm/i915/display/icl_dsi.c | 7 +++++++ >> drivers/gpu/drm/i915/display/vlv_dsi.c | 7 +++++++ >> 2 files changed, 14 insertions(+) >> >> diff --git a/drivers/gpu/drm/i915/display/icl_dsi.c b/drivers/gpu/drm/i915/display/icl_dsi.c >> index 5dcfa7feffa9..885c74f60366 100644 >> --- a/drivers/gpu/drm/i915/display/icl_dsi.c >> +++ b/drivers/gpu/drm/i915/display/icl_dsi.c >> @@ -2070,7 +2070,14 @@ void icl_dsi_init(struct drm_i915_private *dev_priv) >> else >> intel_dsi->ports = BIT(port); >> >> + if (drm_WARN_ON(&dev_priv->drm, intel_connector->panel.vbt.dsi.bl_ports & ~intel_dsi->ports)) >> + intel_connector->panel.vbt.dsi.bl_ports &= intel_dsi->ports; >> + >> intel_dsi->dcs_backlight_ports = intel_connector->panel.vbt.dsi.bl_ports; >> + >> + if (drm_WARN_ON(&dev_priv->drm, intel_connector->panel.vbt.dsi.cabc_ports & ~intel_dsi->ports)) >> + intel_connector->panel.vbt.dsi.cabc_ports &= intel_dsi->ports; >> + >> intel_dsi->dcs_cabc_ports = intel_connector->panel.vbt.dsi.cabc_ports; >> >> for_each_dsi_port(port, intel_dsi->ports) { >> diff --git a/drivers/gpu/drm/i915/display/vlv_dsi.c b/drivers/gpu/drm/i915/display/vlv_dsi.c >> index b9b1fed99874..35136d26e517 100644 >> --- a/drivers/gpu/drm/i915/display/vlv_dsi.c >> +++ b/drivers/gpu/drm/i915/display/vlv_dsi.c >> @@ -1933,7 +1933,14 @@ void vlv_dsi_init(struct drm_i915_private *dev_priv) >> else >> intel_dsi->ports = BIT(port); >> >> + if (drm_WARN_ON(&dev_priv->drm, intel_connector->panel.vbt.dsi.bl_ports & ~intel_dsi->ports)) >> + intel_connector->panel.vbt.dsi.bl_ports &= intel_dsi->ports; >> + >> intel_dsi->dcs_backlight_ports = intel_connector->panel.vbt.dsi.bl_ports; >> + >> + if (drm_WARN_ON(&dev_priv->drm, intel_connector->panel.vbt.dsi.cabc_ports & ~intel_dsi->ports)) >> + intel_connector->panel.vbt.dsi.cabc_ports &= intel_dsi->ports; >> + >> intel_dsi->dcs_cabc_ports = intel_connector->panel.vbt.dsi.cabc_ports; >> >> /* Create a DSI host (and a device) for each port. */ >> -- >> 2.34.1 >> -- Jani Nikula, Intel Open Source Graphics Center
