linux/include
Wayne Lin 5aa1dfcdf0 drm/mst: Refactor the flow for payload allocation/removement
[Why]
Today, the allocation/deallocation steps and status is a bit unclear.

For instance, payload->vc_start_slot = -1 stands for "the failure of
updating DPCD payload ID table" and can also represent as "payload is not
allocated yet". These two cases should be handled differently and hence
better to distinguish them for better understanding.

[How]
Define enumeration - ALLOCATION_LOCAL, ALLOCATION_DFP and ALLOCATION_REMOTE
to distinguish different allocation status. Adjust the code to handle
different status accordingly for better understanding the sequence of
payload allocation and payload removement.

For payload creation, the procedure should look like this:
DRM part 1:
* step 1 - update sw mst mgr variables to add a new payload
* step 2 - add payload at immediate DFP DPCD payload table

Driver:
* Add new payload in HW and sync up with DFP by sending ACT

DRM Part 2:
* Send ALLOCATE_PAYLOAD sideband message to allocate bandwidth along the
  virtual channel.

And as for payload removement, the procedure should look like this:
DRM part 1:
* step 1 - Send ALLOCATE_PAYLOAD sideband message to release bandwidth
           along the virtual channel
* step 2 - Clear payload allocation at immediate DFP DPCD payload table

Driver:
* Remove the payload in HW and sync up with DFP by sending ACT

DRM part 2:
* update sw mst mgr variables to remove the payload

Note that it's fine to fail when communicate with the branch device
connected at immediate downstrean-facing port, but updating variables of
SW mst mgr and HW configuration should be conducted anyway. That's because
it's under commit_tail and we need to complete the HW programming.

Changes since v1:
* Remove the set but not use variable 'old_payload' in function
  'nv50_msto_prepare'. Catched by kernel test robot <lkp@intel.com>

Signed-off-by: Wayne Lin <Wayne.Lin@amd.com>
Signed-off-by: Lyude Paul <lyude@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230807025639.1612361-3-Wayne.Lin@amd.com
2023-09-08 17:00:57 -04:00
..
acpi More ACPI updates for 6.5-rc1 2023-07-06 22:25:06 -07:00
asm-generic vmlinux.lds.h: Remove a reference to no longer used sections .text..refcount 2023-07-11 14:29:43 -07:00
clocksource
crypto This update includes the following changes: 2023-06-30 21:27:13 -07:00
drm drm/mst: Refactor the flow for payload allocation/removement 2023-09-08 17:00:57 -04:00
dt-bindings Another set of clk driver updates and fixes for the merge window. The 2023-07-04 11:07:45 -07:00
keys KEYS: Add forward declaration in asymmetric-parser.h 2023-06-23 16:15:37 +08:00
kunit
kvm Common KVM changes for 6.5: 2023-07-01 07:07:55 -04:00
linux fbdev: Align deferred I/O with naming of helpers 2023-07-31 20:07:24 +02:00
math-emu
media media updates for v6.5-rc1 2023-07-05 10:42:32 -07:00
memory
misc
net net/sched: make psched_mtu() RTNL-less safe 2023-07-12 15:59:33 -07:00
pcmcia
ras
rdma rdma: fix INFINIBAND_USER_ACCESS dependency 2023-07-03 16:55:04 -07:00
rv
scsi SCSI misc on 20230629 2023-06-30 11:57:07 -07:00
soc net: dsa: felix: make vsc9959_tas_guard_bands_update() visible to ocelot->ops 2023-07-06 19:10:22 -07:00
sound ASoC: Updates for v6.5 2023-06-26 15:38:02 +02:00
target SCSI misc on 20230629 2023-06-30 11:57:07 -07:00
trace Including fixes from bluetooth, bpf and wireguard. 2023-07-05 15:44:45 -07:00
uapi drm/nouveau: uapi: don't pass NO_PREFETCH flag implicitly 2023-08-24 01:43:00 +02:00
ufs Merge branch '6.5/scsi-staging' into 6.5/scsi-fixes 2023-07-11 12:15:15 -04:00
vdso
video sticon/parisc: Fix STI console on 64-bit only machines 2023-06-30 17:14:14 +02:00
xen x86: xen: add missing prototypes 2023-06-26 07:47:11 +02:00