It turns out that while disabling i2c bus access from software when the GPU is suspended was a step in the right direction with:
commit 342406e4fbba ("drm/nouveau/i2c: Disable i2c bus access after ->fini()")
We also ended up accidentally breaking the vbios init scripts on some older Tesla GPUs, as apparently said scripts can actually use the i2c bus. Since these scripts are executed before initializing any subdevices, we end up failing to acquire access to the i2c bus which has left a number of cards with their fan controllers uninitialized. Luckily this doesn't break hardware - it just means the fan gets stuck at 100%.
This also means that we've always been using our i2c busses before initializing them during the init scripts for older GPUs, we just didn't notice it until we started preventing them from being used until init. It's pretty impressive this never caused us any issues before!
So, fix this by initializing our i2c pad and busses during subdev pre-init. We skip initializing aux busses during pre-init, as those are guaranteed to only ever be used by nouveau for DP aux transactions.
Signed-off-by: Lyude Paul lyude@redhat.com Tested-by: Marc Meledandri m.meledandri@gmail.com Fixes: 342406e4fbba ("drm/nouveau/i2c: Disable i2c bus access after ->fini()") Cc: stable@vger.kernel.org --- .../gpu/drm/nouveau/nvkm/subdev/i2c/base.c | 20 +++++++++++++++++++ 1 file changed, 20 insertions(+)
diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/i2c/base.c b/drivers/gpu/drm/nouveau/nvkm/subdev/i2c/base.c index ecacb22834d7..719345074711 100644 --- a/drivers/gpu/drm/nouveau/nvkm/subdev/i2c/base.c +++ b/drivers/gpu/drm/nouveau/nvkm/subdev/i2c/base.c @@ -184,6 +184,25 @@ nvkm_i2c_fini(struct nvkm_subdev *subdev, bool suspend) return 0; }
+static int +nvkm_i2c_preinit(struct nvkm_subdev *subdev) +{ + struct nvkm_i2c *i2c = nvkm_i2c(subdev); + struct nvkm_i2c_bus *bus; + struct nvkm_i2c_pad *pad; + + /* + * We init our i2c busses as early as possible, since they may be + * needed by the vbios init scripts on some cards + */ + list_for_each_entry(pad, &i2c->pad, head) + nvkm_i2c_pad_init(pad); + list_for_each_entry(bus, &i2c->bus, head) + nvkm_i2c_bus_init(bus); + + return 0; +} + static int nvkm_i2c_init(struct nvkm_subdev *subdev) { @@ -238,6 +257,7 @@ nvkm_i2c_dtor(struct nvkm_subdev *subdev) static const struct nvkm_subdev_func nvkm_i2c = { .dtor = nvkm_i2c_dtor, + .preinit = nvkm_i2c_preinit, .init = nvkm_i2c_init, .fini = nvkm_i2c_fini, .intr = nvkm_i2c_intr,