drm/nouveau: Don't disable polling in fallback mode

[ Upstream commit 118780066e30c34de3d9349710b51780bfa0ba83 ]

When a fan is controlled via linear fallback without cstate, we
shouldn't stop polling.  Otherwise it won't be adjusted again and
keeps running at an initial crazy pace.

Fixes: 800efb4c2857 ("drm/nouveau/drm/therm/fan: add a fallback if no fan control is specified in the vbios")
Bugzilla: https://bugzilla.suse.com/show_bug.cgi?id=1103356
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=107447
Reported-by: Thomas Blume <thomas.blume@suse.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Reviewed-by: Martin Peres <martin.peres@free.fr>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/therm/base.c b/drivers/gpu/drm/nouveau/nvkm/subdev/therm/base.c
index 3695cde..07914e3 100644 (file)
--- a/drivers/gpu/drm/nouveau/nvkm/subdev/therm/base.c
+++ b/drivers/gpu/drm/nouveau/nvkm/subdev/therm/base.c
@@ -132,11 +132,12 @@ nvkm_therm_update(struct nvkm_therm *therm, int mode)
                        duty = nvkm_therm_update_linear(therm);
                        break;
                case NVBIOS_THERM_FAN_OTHER:
-                       if (therm->cstate)
+                       if (therm->cstate) {
                                duty = therm->cstate;
-                       else
+                               poll = false;
+                       } else {
                                duty = nvkm_therm_update_linear_fallback(therm);
-                       poll = false;
+                       }
                        break;
                }
                immd = false;