From: Hans de Goede hdegoede@redhat.com
[ Upstream commit 30fb97ba4a8e082ba0a5432479d6995472edbd7b ]
The nouveau code used to call drm_fb_helper_initial_config() from nouveau_fbcon_init() before calling drm_dev_register(). This would probe all connectors so that drm_connector->status could be used during backlight registration which runs from nouveau_connector_late_register().
After commit 4a16dd9d18a0 ("drm/nouveau/kms: switch to drm fbdev helpers") the fbdev emulation code, which now is a drm-client, can only run after drm_dev_register(). So during backlight registration the connectors are not probed yet and the drm_connector->status == connected check in nv50_backlight_init() would now always fail.
Replace the drm_connector->status == connected check with a drm_helper_probe_detect() == connected check to fix nv_backlight no longer getting registered because of this.
Fixes: 4a16dd9d18a0 ("drm/nouveau/kms: switch to drm fbdev helpers") Link: https://gitlab.freedesktop.org/drm/nouveau/-/issues/202 Link: https://bugzilla.redhat.com/show_bug.cgi?id=2181941 Signed-off-by: Hans de Goede hdegoede@redhat.com Reviewed-by: Lyude Paul lyude@redhat.com Link: https://patchwork.freedesktop.org/patch/msgid/20230326205433.36485-1-hdegoed... Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/nouveau/nouveau_backlight.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/nouveau/nouveau_backlight.c b/drivers/gpu/drm/nouveau/nouveau_backlight.c index 40409a29f5b69..91b5ecc575380 100644 --- a/drivers/gpu/drm/nouveau/nouveau_backlight.c +++ b/drivers/gpu/drm/nouveau/nouveau_backlight.c @@ -33,6 +33,7 @@ #include <linux/apple-gmux.h> #include <linux/backlight.h> #include <linux/idr.h> +#include <drm/drm_probe_helper.h>
#include "nouveau_drv.h" #include "nouveau_reg.h" @@ -299,8 +300,12 @@ nv50_backlight_init(struct nouveau_backlight *bl, struct nouveau_drm *drm = nouveau_drm(nv_encoder->base.base.dev); struct nvif_object *device = &drm->client.device.object;
+ /* + * Note when this runs the connectors have not been probed yet, + * so nv_conn->base.status is not set yet. + */ if (!nvif_rd32(device, NV50_PDISP_SOR_PWM_CTL(ffs(nv_encoder->dcb->or) - 1)) || - nv_conn->base.status != connector_status_connected) + drm_helper_probe_detect(&nv_conn->base, NULL, false) != connector_status_connected) return -ENODEV;
if (nv_conn->type == DCB_CONNECTOR_eDP) {