On Thu, 4 Feb 2021 at 21:19, Hans Verkuil <hverkuil@xxxxxxxxx> wrote: > > On 01/02/2021 23:13, Ville Syrjälä wrote: > > On Wed, Sep 23, 2020 at 12:13:53PM +1000, Sam McNally wrote: > >> From: Hans Verkuil <hans.verkuil@xxxxxxxxx> > >> > >> For adapters behind an MST hub use the correct AUX channel. > >> > >> Signed-off-by: Hans Verkuil <hans.verkuil@xxxxxxxxx> > >> [sammc@xxxxxxxxxxxx: rebased, removing redundant changes] > >> Signed-off-by: Sam McNally <sammc@xxxxxxxxxxxx> > >> --- > >> > >> (no changes since v1) > >> > >> drivers/gpu/drm/drm_dp_mst_topology.c | 36 +++++++++++++++++++++++++++ > >> 1 file changed, 36 insertions(+) > >> > >> diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c > >> index 15b6cc39a754..0d753201adbd 100644 > >> --- a/drivers/gpu/drm/drm_dp_mst_topology.c > >> +++ b/drivers/gpu/drm/drm_dp_mst_topology.c > >> @@ -2255,6 +2255,9 @@ drm_dp_mst_topology_unlink_port(struct drm_dp_mst_topology_mgr *mgr, > >> drm_dp_mst_topology_put_port(port); > >> } > >> > >> +static ssize_t > >> +drm_dp_mst_aux_transfer(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg); > >> + > >> static struct drm_dp_mst_port * > >> drm_dp_mst_add_port(struct drm_device *dev, > >> struct drm_dp_mst_topology_mgr *mgr, > >> @@ -2271,9 +2274,13 @@ drm_dp_mst_add_port(struct drm_device *dev, > >> port->port_num = port_number; > >> port->mgr = mgr; > >> port->aux.name = "DPMST"; > >> + mutex_init(&port->aux.hw_mutex); > >> + mutex_init(&port->aux.cec.lock); > >> port->aux.dev = dev->dev; > >> port->aux.is_remote = true; > >> > >> + port->aux.transfer = drm_dp_mst_aux_transfer; > >> + > > > > This was supposed to be handled via higher levels checking for > > is_remote==true. > > Ah, I suspect this patch can be dropped entirely: it predates commit 2f221a5efed4 > ("drm/dp_mst: Add MST support to DP DPCD R/W functions"). > > It looks like that commit basically solved what this older patch attempts to do > as well. > > Sam, can you test if it works without this patch? It almost just works; drm_dp_cec uses whether aux.transfer is non-null to filter out non-DP connectors. Using aux.is_remote as another signal indicating a DP connector seems plausible. We can drop this patch. Thanks all! > > Regards, > > Hans > > > > >> /* initialize the MST downstream port's AUX crc work queue */ > >> drm_dp_remote_aux_init(&port->aux); > >> > >> @@ -3503,6 +3510,35 @@ static int drm_dp_send_up_ack_reply(struct drm_dp_mst_topology_mgr *mgr, > >> return 0; > >> } > >> > >> +static ssize_t > >> +drm_dp_mst_aux_transfer(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg) > >> +{ > >> + struct drm_dp_mst_port *port = > >> + container_of(aux, struct drm_dp_mst_port, aux); > >> + int ret; > >> + > >> + switch (msg->request & ~DP_AUX_I2C_MOT) { > >> + case DP_AUX_NATIVE_WRITE: > >> + case DP_AUX_I2C_WRITE: > >> + case DP_AUX_I2C_WRITE_STATUS_UPDATE: > >> + ret = drm_dp_send_dpcd_write(port->mgr, port, msg->address, > >> + msg->size, msg->buffer); > > > > That doesn't make sense to me. I2c writes and DPCD writes > > are definitely not the same thing. > > > > aux->transfer is a very low level thing. I don't think it's the > > correct level of abstraction for sideband. > > > >> + break; > >> + > >> + case DP_AUX_NATIVE_READ: > >> + case DP_AUX_I2C_READ: > >> + ret = drm_dp_send_dpcd_read(port->mgr, port, msg->address, > >> + msg->size, msg->buffer); > >> + break; > >> + > >> + default: > >> + ret = -EINVAL; > >> + break; > >> + } > >> + > >> + return ret; > >> +} > >> + > >> static int drm_dp_get_vc_payload_bw(u8 dp_link_bw, u8 dp_link_count) > >> { > >> if (dp_link_bw == 0 || dp_link_count == 0) > >> -- > >> 2.28.0.681.g6f77f65b4e-goog > >> > >> _______________________________________________ > >> dri-devel mailing list > >> dri-devel@xxxxxxxxxxxxxxxxxxxxx > >> https://lists.freedesktop.org/mailman/listinfo/dri-devel > > > _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel