| Message ID | 20240206153910.1758057-2-imre.deak@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/i915: Prevent HW access during init from connector hooks | expand |
On Tue, 2024-02-06 at 17:39 +0200, Imre Deak wrote: > Prevent accessing the HW from the SDVO/TV get_modes connector hook. > Returning 0 from the hook will make the caller - > drm_helper_probe_single_connector_modes() - keep the previously > detected > mode list of the connector. I don't see where this is done? Not sure if looking at wrong place, but I see it tries using some override edid and in case that fails as well uses drm_add_modes_noedid? > > Signed-off-by: Imre Deak <imre.deak@intel.com> > --- > drivers/gpu/drm/i915/display/intel_sdvo.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/drivers/gpu/drm/i915/display/intel_sdvo.c > b/drivers/gpu/drm/i915/display/intel_sdvo.c > index 2571ef5a1b211..ccea0efbd136f 100644 > --- a/drivers/gpu/drm/i915/display/intel_sdvo.c > +++ b/drivers/gpu/drm/i915/display/intel_sdvo.c > @@ -2287,6 +2287,7 @@ static const struct drm_display_mode > sdvo_tv_modes[] = { > static int intel_sdvo_get_tv_modes(struct drm_connector *connector) I see intel_sdvo_get_tv_modes is called from intel_sdvo_get_modes. Why there is no need to do the same in intel_sdvo_get_lvds_modes and intel_sdvo_get_ddc_modes as well? BR, Jouni Högander > { > struct intel_sdvo *intel_sdvo = > intel_attached_sdvo(to_intel_connector(connector)); > + struct drm_i915_private *i915 = to_i915(intel_sdvo- > >base.base.dev); > struct intel_sdvo_connector *intel_sdvo_connector = > to_intel_sdvo_connector(connector); > const struct drm_connector_state *conn_state = connector- > >state; > @@ -2298,6 +2299,9 @@ static int intel_sdvo_get_tv_modes(struct > drm_connector *connector) > DRM_DEBUG_KMS("[CONNECTOR:%d:%s]\n", > connector->base.id, connector->name); > > + if (!intel_display_driver_check_access(i915)) > + return 0; > + > /* > * Read the list of supported input resolutions for the > selected TV > * format.
On Wed, 2024-02-07 at 15:26 +0200, Hogander, Jouni wrote: > On Tue, 2024-02-06 at 17:39 +0200, Imre Deak wrote: > > Prevent accessing the HW from the SDVO/TV get_modes connector hook. > > Returning 0 from the hook will make the caller - > > drm_helper_probe_single_connector_modes() - keep the previously > > detected > > mode list of the connector. > > I don't see where this is done? Not sure if looking at wrong place, > but > I see it tries using some override edid and in case that fails as > well > uses drm_add_modes_noedid? > > > > > Signed-off-by: Imre Deak <imre.deak@intel.com> > > --- > > drivers/gpu/drm/i915/display/intel_sdvo.c | 4 ++++ > > 1 file changed, 4 insertions(+) > > > > diff --git a/drivers/gpu/drm/i915/display/intel_sdvo.c > > b/drivers/gpu/drm/i915/display/intel_sdvo.c > > index 2571ef5a1b211..ccea0efbd136f 100644 > > --- a/drivers/gpu/drm/i915/display/intel_sdvo.c > > +++ b/drivers/gpu/drm/i915/display/intel_sdvo.c > > @@ -2287,6 +2287,7 @@ static const struct drm_display_mode > > sdvo_tv_modes[] = { > > static int intel_sdvo_get_tv_modes(struct drm_connector > > *connector) > > I see intel_sdvo_get_tv_modes is called from intel_sdvo_get_modes. > Why > there is no need to do the same in intel_sdvo_get_lvds_modes and > intel_sdvo_get_ddc_modes as well? It seems you are taking care of intel_svdo_get_ddc_modes in next patch. Intel_svdo_get_lvds_modes doesn't touch the hw -> nothing to do there. > > BR, > > Jouni Högander > > > { > > struct intel_sdvo *intel_sdvo = > > intel_attached_sdvo(to_intel_connector(connector)); > > + struct drm_i915_private *i915 = to_i915(intel_sdvo- > > > base.base.dev); > > struct intel_sdvo_connector *intel_sdvo_connector = > > to_intel_sdvo_connector(connector); > > const struct drm_connector_state *conn_state = connector- > > > state; > > @@ -2298,6 +2299,9 @@ static int intel_sdvo_get_tv_modes(struct > > drm_connector *connector) > > DRM_DEBUG_KMS("[CONNECTOR:%d:%s]\n", > > connector->base.id, connector->name); > > > > + if (!intel_display_driver_check_access(i915)) > > + return 0; > > + > > /* > > * Read the list of supported input resolutions for the > > selected TV > > * format. >
On Wed, Feb 07, 2024 at 03:45:15PM +0200, Hogander, Jouni wrote: > On Wed, 2024-02-07 at 15:26 +0200, Hogander, Jouni wrote: > > On Tue, 2024-02-06 at 17:39 +0200, Imre Deak wrote: > > > Prevent accessing the HW from the SDVO/TV get_modes connector hook. > > > Returning 0 from the hook will make the caller - > > > drm_helper_probe_single_connector_modes() - keep the previously > > > detected > > > mode list of the connector. > > > > > I don't see where this is done? Not sure if looking at wrong place, > > but I see it tries using some override edid and in case that fails > > as well uses drm_add_modes_noedid? Some default and EDID override modes are also added to the connector mode list, similarly to when the HW access in intel_sdvo_get_tv_modes() fails (along with any modes specified via the kernel command line, which happens unconditionally, see drm_helper_probe_add_cmdline_mode()). All the modes detected by the encoder detect and the connector get_modes hooks gets added to the drm_connector::probed_modes list. From this __drm_helper_update_and_validate() will copy any new modes to the drm_connector::modes list (which will be returned to user space/kernel client). Thus, returning 0 from the above TV connector get_modes hook will preserve the list of modes on the drm_connector::modes list from an earlier encoder detect/connector get_modes call. > > > > > > > > Signed-off-by: Imre Deak <imre.deak@intel.com> > > > --- > > > drivers/gpu/drm/i915/display/intel_sdvo.c | 4 ++++ > > > 1 file changed, 4 insertions(+) > > > > > > diff --git a/drivers/gpu/drm/i915/display/intel_sdvo.c > > > b/drivers/gpu/drm/i915/display/intel_sdvo.c > > > index 2571ef5a1b211..ccea0efbd136f 100644 > > > --- a/drivers/gpu/drm/i915/display/intel_sdvo.c > > > +++ b/drivers/gpu/drm/i915/display/intel_sdvo.c > > > @@ -2287,6 +2287,7 @@ static const struct drm_display_mode > > > sdvo_tv_modes[] = { > > > static int intel_sdvo_get_tv_modes(struct drm_connector > > > *connector) > > > > I see intel_sdvo_get_tv_modes is called from intel_sdvo_get_modes. > > Why > > there is no need to do the same in intel_sdvo_get_lvds_modes and > > intel_sdvo_get_ddc_modes as well? > > It seems you are taking care of intel_svdo_get_ddc_modes in next patch. > Intel_svdo_get_lvds_modes doesn't touch the hw -> nothing to do there. > > > > > BR, > > > > Jouni Högander > > > > > { > > > struct intel_sdvo *intel_sdvo = > > > intel_attached_sdvo(to_intel_connector(connector)); > > > + struct drm_i915_private *i915 = to_i915(intel_sdvo- > > > > base.base.dev); > > > struct intel_sdvo_connector *intel_sdvo_connector = > > > to_intel_sdvo_connector(connector); > > > const struct drm_connector_state *conn_state = connector- > > > > state; > > > @@ -2298,6 +2299,9 @@ static int intel_sdvo_get_tv_modes(struct > > > drm_connector *connector) > > > DRM_DEBUG_KMS("[CONNECTOR:%d:%s]\n", > > > connector->base.id, connector->name); > > > > > > + if (!intel_display_driver_check_access(i915)) > > > + return 0; > > > + > > > /* > > > * Read the list of supported input resolutions for the > > > selected TV > > > * format. > > >
On Wed, Feb 07, 2024 at 03:45:15PM +0200, Hogander, Jouni wrote: > On Wed, 2024-02-07 at 15:26 +0200, Hogander, Jouni wrote: > > On Tue, 2024-02-06 at 17:39 +0200, Imre Deak wrote: > > > Prevent accessing the HW from the SDVO/TV get_modes connector hook. > > > Returning 0 from the hook will make the caller - > > > drm_helper_probe_single_connector_modes() - keep the previously > > > detected > > > mode list of the connector. > > > > I don't see where this is done? Not sure if looking at wrong place, > > but > > I see it tries using some override edid and in case that fails as > > well > > uses drm_add_modes_noedid? > > > > > > > > Signed-off-by: Imre Deak <imre.deak@intel.com> > > > --- > > > drivers/gpu/drm/i915/display/intel_sdvo.c | 4 ++++ > > > 1 file changed, 4 insertions(+) > > > > > > diff --git a/drivers/gpu/drm/i915/display/intel_sdvo.c > > > b/drivers/gpu/drm/i915/display/intel_sdvo.c > > > index 2571ef5a1b211..ccea0efbd136f 100644 > > > --- a/drivers/gpu/drm/i915/display/intel_sdvo.c > > > +++ b/drivers/gpu/drm/i915/display/intel_sdvo.c > > > @@ -2287,6 +2287,7 @@ static const struct drm_display_mode > > > sdvo_tv_modes[] = { > > > static int intel_sdvo_get_tv_modes(struct drm_connector > > > *connector) > > > > I see intel_sdvo_get_tv_modes is called from intel_sdvo_get_modes. > > Why there is no need to do the same in intel_sdvo_get_lvds_modes and > > intel_sdvo_get_ddc_modes as well? > > It seems you are taking care of intel_svdo_get_ddc_modes in next patch. > Intel_svdo_get_lvds_modes doesn't touch the hw -> nothing to do there. Yes, all the connectors that read out an EDID - vs. the TV connector which doesn't - is handled by the next patch. And yes, the connectors which don't access the HW in the get_modes hook doesn't need this check. Btw, I think all the connectors should work - eventually - in this way: access the HW only in the encoder detect hook and from the get_modes hook only return the detected mode list w/o accessing the HW. DP-SST and HDMI do already the correct thing wrt. this. > > > > > BR, > > > > Jouni Högander > > > > > { > > > struct intel_sdvo *intel_sdvo = > > > intel_attached_sdvo(to_intel_connector(connector)); > > > + struct drm_i915_private *i915 = to_i915(intel_sdvo- > > > > base.base.dev); > > > struct intel_sdvo_connector *intel_sdvo_connector = > > > to_intel_sdvo_connector(connector); > > > const struct drm_connector_state *conn_state = connector- > > > > state; > > > @@ -2298,6 +2299,9 @@ static int intel_sdvo_get_tv_modes(struct > > > drm_connector *connector) > > > DRM_DEBUG_KMS("[CONNECTOR:%d:%s]\n", > > > connector->base.id, connector->name); > > > > > > + if (!intel_display_driver_check_access(i915)) > > > + return 0; > > > + > > > /* > > > * Read the list of supported input resolutions for the > > > selected TV > > > * format. > > >
On Wed, 2024-02-07 at 16:16 +0200, Imre Deak wrote: > On Wed, Feb 07, 2024 at 03:45:15PM +0200, Hogander, Jouni wrote: > > On Wed, 2024-02-07 at 15:26 +0200, Hogander, Jouni wrote: > > > On Tue, 2024-02-06 at 17:39 +0200, Imre Deak wrote: > > > > Prevent accessing the HW from the SDVO/TV get_modes connector > > > > hook. > > > > Returning 0 from the hook will make the caller - > > > > drm_helper_probe_single_connector_modes() - keep the previously > > > > detected > > > > mode list of the connector. > > > > > > I don't see where this is done? Not sure if looking at wrong > > > place, > > > but > > > I see it tries using some override edid and in case that fails as > > > well > > > uses drm_add_modes_noedid? > > > > > > > > > > > Signed-off-by: Imre Deak <imre.deak@intel.com> > > > > --- > > > > drivers/gpu/drm/i915/display/intel_sdvo.c | 4 ++++ > > > > 1 file changed, 4 insertions(+) > > > > > > > > diff --git a/drivers/gpu/drm/i915/display/intel_sdvo.c > > > > b/drivers/gpu/drm/i915/display/intel_sdvo.c > > > > index 2571ef5a1b211..ccea0efbd136f 100644 > > > > --- a/drivers/gpu/drm/i915/display/intel_sdvo.c > > > > +++ b/drivers/gpu/drm/i915/display/intel_sdvo.c > > > > @@ -2287,6 +2287,7 @@ static const struct drm_display_mode > > > > sdvo_tv_modes[] = { > > > > static int intel_sdvo_get_tv_modes(struct drm_connector > > > > *connector) > > > > > > I see intel_sdvo_get_tv_modes is called from > > > intel_sdvo_get_modes. > > > Why there is no need to do the same in intel_sdvo_get_lvds_modes > > > and > > > intel_sdvo_get_ddc_modes as well? > > > > It seems you are taking care of intel_svdo_get_ddc_modes in next > > patch. > > Intel_svdo_get_lvds_modes doesn't touch the hw -> nothing to do > > there. > > Yes, all the connectors that read out an EDID - vs. the TV connector > which doesn't - is handled by the next patch. And yes, the connectors > which don't access the HW in the get_modes hook doesn't need this > check. > Btw, I think all the connectors should work - eventually - in this > way: > access the HW only in the encoder detect hook and from the get_modes > hook only return the detected mode list w/o accessing the HW. DP-SST > and > HDMI do already the correct thing wrt. this. > Thank you for the clarification. Reviewed-by: Jouni Högander <jouni.hogander@intel.com> > > > > > > > > BR, > > > > > > Jouni Högander > > > > > > > { > > > > struct intel_sdvo *intel_sdvo = > > > > intel_attached_sdvo(to_intel_connector(connector)); > > > > + struct drm_i915_private *i915 = to_i915(intel_sdvo- > > > > > base.base.dev); > > > > struct intel_sdvo_connector *intel_sdvo_connector = > > > > to_intel_sdvo_connector(connector); > > > > const struct drm_connector_state *conn_state = > > > > connector- > > > > > state; > > > > @@ -2298,6 +2299,9 @@ static int intel_sdvo_get_tv_modes(struct > > > > drm_connector *connector) > > > > DRM_DEBUG_KMS("[CONNECTOR:%d:%s]\n", > > > > connector->base.id, connector->name); > > > > > > > > + if (!intel_display_driver_check_access(i915)) > > > > + return 0; > > > > + > > > > /* > > > > * Read the list of supported input resolutions for the > > > > selected TV > > > > * format. > > > > >
On Wed, Feb 07, 2024 at 04:10:28PM +0200, Imre Deak wrote: > On Wed, Feb 07, 2024 at 03:45:15PM +0200, Hogander, Jouni wrote: > > On Wed, 2024-02-07 at 15:26 +0200, Hogander, Jouni wrote: > > > On Tue, 2024-02-06 at 17:39 +0200, Imre Deak wrote: > > > > Prevent accessing the HW from the SDVO/TV get_modes connector hook. > > > > Returning 0 from the hook will make the caller - > > > > drm_helper_probe_single_connector_modes() - keep the previously > > > > detected > > > > mode list of the connector. > > > > > > > > I don't see where this is done? Not sure if looking at wrong place, > > > but I see it tries using some override edid and in case that fails > > > as well uses drm_add_modes_noedid? > > Some default and EDID override modes are also added to the connector > mode list, similarly to when the HW access in intel_sdvo_get_tv_modes() > fails (along with any modes specified via the kernel command line, which > happens unconditionally, see drm_helper_probe_add_cmdline_mode()). > > All the modes detected by the encoder detect and the connector get_modes > hooks gets added to the drm_connector::probed_modes list. From this > __drm_helper_update_and_validate() will copy any new modes to the > drm_connector::modes list (which will be returned to user space/kernel > client). Thus, returning 0 from the above TV connector get_modes hook > will preserve the list of modes on the drm_connector::modes list from an > earlier encoder detect/connector get_modes call. Drat, I realized the above is not quite correct. All the modes on drm_connector:modes will be flagged as MODE_STALE and removed by drm_mode_prune_invalid(). This means if get_modes() returns 0 only the default/override modes will be returned, not the ones detected in an earlier detect/get_modes call. I think this is ok, matching the case where HW access fails, but needs at least a clarficiation in the comment. Thanks for questioning it.. > > > > > > > > > > > > Signed-off-by: Imre Deak <imre.deak@intel.com> > > > > --- > > > > drivers/gpu/drm/i915/display/intel_sdvo.c | 4 ++++ > > > > 1 file changed, 4 insertions(+) > > > > > > > > diff --git a/drivers/gpu/drm/i915/display/intel_sdvo.c > > > > b/drivers/gpu/drm/i915/display/intel_sdvo.c > > > > index 2571ef5a1b211..ccea0efbd136f 100644 > > > > --- a/drivers/gpu/drm/i915/display/intel_sdvo.c > > > > +++ b/drivers/gpu/drm/i915/display/intel_sdvo.c > > > > @@ -2287,6 +2287,7 @@ static const struct drm_display_mode > > > > sdvo_tv_modes[] = { > > > > static int intel_sdvo_get_tv_modes(struct drm_connector > > > > *connector) > > > > > > I see intel_sdvo_get_tv_modes is called from intel_sdvo_get_modes. > > > Why > > > there is no need to do the same in intel_sdvo_get_lvds_modes and > > > intel_sdvo_get_ddc_modes as well? > > > > It seems you are taking care of intel_svdo_get_ddc_modes in next patch. > > Intel_svdo_get_lvds_modes doesn't touch the hw -> nothing to do there. > > > > > > > > BR, > > > > > > Jouni Högander > > > > > > > { > > > > struct intel_sdvo *intel_sdvo = > > > > intel_attached_sdvo(to_intel_connector(connector)); > > > > + struct drm_i915_private *i915 = to_i915(intel_sdvo- > > > > > base.base.dev); > > > > struct intel_sdvo_connector *intel_sdvo_connector = > > > > to_intel_sdvo_connector(connector); > > > > const struct drm_connector_state *conn_state = connector- > > > > > state; > > > > @@ -2298,6 +2299,9 @@ static int intel_sdvo_get_tv_modes(struct > > > > drm_connector *connector) > > > > DRM_DEBUG_KMS("[CONNECTOR:%d:%s]\n", > > > > connector->base.id, connector->name); > > > > > > > > + if (!intel_display_driver_check_access(i915)) > > > > + return 0; > > > > + > > > > /* > > > > * Read the list of supported input resolutions for the > > > > selected TV > > > > * format. > > > > >
diff --git a/drivers/gpu/drm/i915/display/intel_sdvo.c b/drivers/gpu/drm/i915/display/intel_sdvo.c index 2571ef5a1b211..ccea0efbd136f 100644 --- a/drivers/gpu/drm/i915/display/intel_sdvo.c +++ b/drivers/gpu/drm/i915/display/intel_sdvo.c @@ -2287,6 +2287,7 @@ static const struct drm_display_mode sdvo_tv_modes[] = { static int intel_sdvo_get_tv_modes(struct drm_connector *connector) { struct intel_sdvo *intel_sdvo = intel_attached_sdvo(to_intel_connector(connector)); + struct drm_i915_private *i915 = to_i915(intel_sdvo->base.base.dev); struct intel_sdvo_connector *intel_sdvo_connector = to_intel_sdvo_connector(connector); const struct drm_connector_state *conn_state = connector->state; @@ -2298,6 +2299,9 @@ static int intel_sdvo_get_tv_modes(struct drm_connector *connector) DRM_DEBUG_KMS("[CONNECTOR:%d:%s]\n", connector->base.id, connector->name); + if (!intel_display_driver_check_access(i915)) + return 0; + /* * Read the list of supported input resolutions for the selected TV * format.
Prevent accessing the HW from the SDVO/TV get_modes connector hook. Returning 0 from the hook will make the caller - drm_helper_probe_single_connector_modes() - keep the previously detected mode list of the connector. Signed-off-by: Imre Deak <imre.deak@intel.com> --- drivers/gpu/drm/i915/display/intel_sdvo.c | 4 ++++ 1 file changed, 4 insertions(+)