Hi, On 3-Oct-24 5:54 PM, Alex Deucher wrote: > + Hans > > On Thu, Oct 3, 2024 at 2:33 AM Wu Hoi Pok <wuhoipok@xxxxxxxxx> wrote: >> >> This is a fix patch not tested yet, >> for a bug I introduce in previous rework of radeon driver. >> The bug is a null dereference in 'aux.dev', which is the >> 'device' not registered, resulting in kernel panic. By having >> 'late_register', the connector should be registered after >> 'drm_dev_register' automatically. >> >> Please help testing thank you. >> >> Signed-off-by: Wu Hoi Pok <wuhoipok@xxxxxxxxx> Thank you both for the Cc and the patch. I can confirm that this fixes the crash which I was seeing. Also IHMO this should have a fixes tag for the original commit introducing the problem: Fixes: 90985660ba48 ("drm/radeon: remove load callback from kms_driver") Tested-by: Hans de Goede <hdegoede@xxxxxxxxxx> Regards, Hans >> --- >> drivers/gpu/drm/radeon/atombios_dp.c | 9 ++------- >> drivers/gpu/drm/radeon/radeon_connectors.c | 17 +++++++++++++++++ >> 2 files changed, 19 insertions(+), 7 deletions(-) >> >> diff --git a/drivers/gpu/drm/radeon/atombios_dp.c b/drivers/gpu/drm/radeon/atombios_dp.c >> index fca8b08535a5..6328627b7c34 100644 >> --- a/drivers/gpu/drm/radeon/atombios_dp.c >> +++ b/drivers/gpu/drm/radeon/atombios_dp.c >> @@ -228,10 +228,8 @@ void radeon_dp_aux_init(struct radeon_connector *radeon_connector) >> { >> struct drm_device *dev = radeon_connector->base.dev; >> struct radeon_device *rdev = dev->dev_private; >> - int ret; >> >> radeon_connector->ddc_bus->rec.hpd = radeon_connector->hpd.hpd; >> - radeon_connector->ddc_bus->aux.dev = radeon_connector->base.kdev; >> radeon_connector->ddc_bus->aux.drm_dev = radeon_connector->base.dev; >> if (ASIC_IS_DCE5(rdev)) { >> if (radeon_auxch) >> @@ -242,11 +240,8 @@ void radeon_dp_aux_init(struct radeon_connector *radeon_connector) >> radeon_connector->ddc_bus->aux.transfer = radeon_dp_aux_transfer_atom; >> } >> >> - ret = drm_dp_aux_register(&radeon_connector->ddc_bus->aux); >> - if (!ret) >> - radeon_connector->ddc_bus->has_aux = true; >> - >> - WARN(ret, "drm_dp_aux_register() failed with error %d\n", ret); >> + drm_dp_aux_init(&radeon_connector->ddc_bus->aux); >> + radeon_connector->ddc_bus->has_aux = true; >> } >> >> /***** general DP utility functions *****/ >> diff --git a/drivers/gpu/drm/radeon/radeon_connectors.c b/drivers/gpu/drm/radeon/radeon_connectors.c >> index 528a8f3677c2..f9c73c55f04f 100644 >> --- a/drivers/gpu/drm/radeon/radeon_connectors.c >> +++ b/drivers/gpu/drm/radeon/radeon_connectors.c >> @@ -1786,6 +1786,20 @@ static enum drm_mode_status radeon_dp_mode_valid(struct drm_connector *connector >> return MODE_OK; >> } >> >> +static int >> +radeon_connector_late_register(struct drm_connector *connector) >> +{ >> + struct radeon_connector *radeon_connector = to_radeon_connector(connector); >> + int r = 0; >> + >> + if (radeon_connector->ddc_bus->has_aux) { >> + radeon_connector->ddc_bus->aux.dev = radeon_connector->base.kdev; >> + r = drm_dp_aux_register(&radeon_connector->ddc_bus->aux); >> + } >> + >> + return r; >> +} >> + >> static const struct drm_connector_helper_funcs radeon_dp_connector_helper_funcs = { >> .get_modes = radeon_dp_get_modes, >> .mode_valid = radeon_dp_mode_valid, >> @@ -1800,6 +1814,7 @@ static const struct drm_connector_funcs radeon_dp_connector_funcs = { >> .early_unregister = radeon_connector_unregister, >> .destroy = radeon_connector_destroy, >> .force = radeon_dvi_force, >> + .late_register = radeon_connector_late_register, >> }; >> >> static const struct drm_connector_funcs radeon_edp_connector_funcs = { >> @@ -1810,6 +1825,7 @@ static const struct drm_connector_funcs radeon_edp_connector_funcs = { >> .early_unregister = radeon_connector_unregister, >> .destroy = radeon_connector_destroy, >> .force = radeon_dvi_force, >> + .late_register = radeon_connector_late_register, >> }; >> >> static const struct drm_connector_funcs radeon_lvds_bridge_connector_funcs = { >> @@ -1820,6 +1836,7 @@ static const struct drm_connector_funcs radeon_lvds_bridge_connector_funcs = { >> .early_unregister = radeon_connector_unregister, >> .destroy = radeon_connector_destroy, >> .force = radeon_dvi_force, >> + .late_register = radeon_connector_late_register, >> }; >> >> void >> -- >> 2.46.2 >> >