From 13a86519202c5d119d83640d6f781f3181205d2c Mon Sep 17 00:00:00 2001 From: Ben Skeggs Date: Wed, 19 Jul 2017 16:49:59 +1000 Subject: drm/nouveau/i2c/gf119-: add support for address-only transactions Since switching the I2C-over-AUX helpers, there have been regressions on some display combinations due to us not having support for "address only" transactions. This commits enables support for them for GF119 and newer. Earlier GPUs have been reverted to a custom I2C-over-AUX algorithm. Signed-off-by: Ben Skeggs --- drivers/gpu/drm/nouveau/nvkm/subdev/i2c/aux.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'drivers/gpu/drm/nouveau/nvkm/subdev/i2c/aux.c') diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/i2c/aux.c b/drivers/gpu/drm/nouveau/nvkm/subdev/i2c/aux.c index d172e42dd228..4c1f547da463 100644 --- a/drivers/gpu/drm/nouveau/nvkm/subdev/i2c/aux.c +++ b/drivers/gpu/drm/nouveau/nvkm/subdev/i2c/aux.c @@ -117,6 +117,10 @@ int nvkm_i2c_aux_xfer(struct nvkm_i2c_aux *aux, bool retry, u8 type, u32 addr, u8 *data, u8 *size) { + if (!*size && !aux->func->address_only) { + AUX_ERR(aux, "address-only transaction dropped"); + return -ENOSYS; + } return aux->func->xfer(aux, retry, type, addr, data, size); } -- cgit v1.2.3-55-g7522