diff options
| author | Mika Westerberg <mika.westerberg@linux.intel.com> | 2022-03-23 16:45:39 +0200 |
|---|---|---|
| committer | Mika Westerberg <mika.westerberg@linux.intel.com> | 2023-01-17 11:37:16 +0200 |
| commit | 6ce3563520be90a155706bafc186fc264a13850e (patch) | |
| tree | 8c3c4adba67ab76fdb10a9e3e98498f573a853d4 /drivers/thunderbolt/tb.h | |
| parent | 630f211be7c0a8cf693fef2b6d77d0ac357041e0 (diff) | |
thunderbolt: Add support for DisplayPort bandwidth allocation mode
The USB4 spec defines an optional feature that allows the connection
manager to negotiate with the graphics through DPCD registers changes in
the bandwidth allocation dynamically. This is referred as "bandwidth
allocation mode" in the spec. The connection manager uses DP IN adapters
registers to communicate with the graphics, and also gets notifications
from these adapters when the graphics wants to change the bandwidth
allocation. Both the connection manager and the graphics driver needs to
support this.
We check if the DP IN adapter supports this and if it does enable it
before establishing a DP tunnel. Then we react on DP_BW notifications
coming from the DP IN adapter and update the bandwidth allocation
accordingly (within the maximum common capabilities the DP IN/OUT
support).
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Diffstat (limited to 'drivers/thunderbolt/tb.h')
| -rw-r--r-- | drivers/thunderbolt/tb.h | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/drivers/thunderbolt/tb.h b/drivers/thunderbolt/tb.h index cd6c9eeaf049..2953cf38c29e 100644 --- a/drivers/thunderbolt/tb.h +++ b/drivers/thunderbolt/tb.h @@ -224,6 +224,23 @@ struct tb_switch { }; /** + * struct tb_bandwidth_group - Bandwidth management group + * @tb: Pointer to the domain the group belongs to + * @index: Index of the group (aka Group_ID). Valid values %1-%7 + * @ports: DP IN adapters belonging to this group are linked here + * + * Any tunnel that requires isochronous bandwidth (that's DP for now) is + * attached to a bandwidth group. All tunnels going through the same + * USB4 links share the same group and can dynamically distribute the + * bandwidth within the group. + */ +struct tb_bandwidth_group { + struct tb *tb; + int index; + struct list_head ports; +}; + +/** * struct tb_port - a thunderbolt port, part of a tb_switch * @config: Cached port configuration read from registers * @sw: Switch the port belongs to @@ -247,6 +264,9 @@ struct tb_switch { * @ctl_credits: Buffers reserved for control path * @dma_credits: Number of credits allocated for DMA tunneling for all * DMA paths through this port. + * @group: Bandwidth allocation group the adapter is assigned to. Only + * used for DP IN adapters for now. + * @group_list: The adapter is linked to the group's list of ports through this * * In USB4 terminology this structure represents an adapter (protocol or * lane adapter). @@ -272,6 +292,8 @@ struct tb_port { unsigned int total_credits; unsigned int ctl_credits; unsigned int dma_credits; + struct tb_bandwidth_group *group; + struct list_head group_list; }; /** |