[PATCH v11 00/21] Synopsys DisplayPort Controller improvements for Rockchip platforms

[Heiko Stübner]

Hi Sebastian,

Am Donnerstag, 6. August 2026, 19:02:06 Mitteleuropäische Sommerzeit schrieb Sebastian Reichel:
> This patch series updates the Synopsys Designware DisplayPort bridge
> together with the only existing user: The Rockchip RK3576/RK3588:
> 
>  1. Follow-up bridges (PHY, USB-C connector)
>     This is needed to get USB-C DP AltMode working; I've followed
>     the Qualcomm driver as reference
> 
>  2. Runtime PM
>     The initial driver has been upstreamed without RPM; add it to
>     avoid wasting power when nothing is plugged
> 
>  3. Audio
>     The initial driver has been upstreamed without audio support;
>     this adds all missing bits for audio with single stream transport
> 
> To properly make use of the bridge code the following USBDP PHY series
> is also needed:
> 
> https://lore.kernel.org/all/20260714-rockchip-usbdp-cleanup-v13-0-6cb3e769d4c5@collabora.com/

I've now had time to test both series (dw-dp + usbdp) :-)

- On my 1080p display I get nice output
- On my 4K display I get "some" output after increasing the ACLK_VOP to
  750MHz - although the output itself is garbled. Before there was no
  output at all
- hotplug works correctly, typec-display altmode gets correctly set up
  and the drm driver enables output [0]
- cable being plugged in on boot does not work completely. The usb-side
  gets detected correctly, but the drm-side stays at disconnected
  The usb+typec-related kernel messages look the same though. [1]
  Unplugging and replugging then produces display output.


Heiko


[0]
[  221.536599] platform xhci-hcd.4.auto: bus: 'platform': __driver_probe_device: matched device with driver xhci-hcd
[  221.548102] platform xhci-hcd.4.auto: bus: 'platform': really_probe: probing driver xhci-hcd with device
[  221.558836] xhci-hcd xhci-hcd.4.auto: xHCI Host Controller
[  221.564990] xhci-hcd xhci-hcd.4.auto: new USB bus registered, assigned bus number 5
[  221.573652] xhci-hcd xhci-hcd.4.auto: hcc params 0x0220fe64 hci version 0x110 quirks 0x0000808002000010
[  221.584184] xhci-hcd xhci-hcd.4.auto: irq 108, io mem 0xfc000000
[  221.591002] xhci-hcd xhci-hcd.4.auto: xHCI Host Controller
[  221.597149] xhci-hcd xhci-hcd.4.auto: new USB bus registered, assigned bus number 6
[  221.605724] xhci-hcd xhci-hcd.4.auto: Host supports USB 3.0 SuperSpeed
[  221.613368] usb usb5: bus: 'usb': __driver_probe_device: matched device with driver usb
[  221.622335] usb usb5: bus: 'usb': really_probe: probing driver usb with device
[  221.630503] usb 5-0:1.0: bus: 'usb': __driver_probe_device: matched device with driver hub
[  221.639776] usb 5-0:1.0: bus: 'usb': really_probe: probing driver hub with device
[  221.648171] hub 5-0:1.0: USB hub found
[  221.652396] hub 5-0:1.0: 1 port detected
[  221.656891] hub 5-0:1.0: driver: 'hub': driver_bound: bound to device
[  221.664125] hub 5-0:1.0: bus: 'usb': really_probe: bound device to driver hub
[  221.672155] usb usb5: driver: 'usb': driver_bound: bound to device
[  221.679099] usb usb5: bus: 'usb': really_probe: bound device to driver usb
[  221.686864] usb usb6: We don't know the algorithms for LPM for this host, disabling LPM.
[  221.696175] usb usb6: bus: 'usb': __driver_probe_device: matched device with driver usb
[  221.705143] usb usb6: bus: 'usb': really_probe: probing driver usb with device
[  221.713323] usb 6-0:1.0: bus: 'usb': __driver_probe_device: matched device with driver hub
[  221.722578] usb 6-0:1.0: bus: 'usb': really_probe: probing driver hub with device
[  221.730961] hub 6-0:1.0: USB hub found
[  221.735170] hub 6-0:1.0: 1 port detected
[  221.739647] hub 6-0:1.0: driver: 'hub': driver_bound: bound to device
[  221.746889] hub 6-0:1.0: bus: 'usb': really_probe: bound device to driver hub
[  221.754920] usb usb6: driver: 'usb': driver_bound: bound to device
[  221.761867] usb usb6: bus: 'usb': really_probe: bound device to driver usb
[  221.769602] xhci-hcd xhci-hcd.4.auto: driver: 'xhci-hcd': driver_bound: bound to device
[  221.778585] xhci-hcd xhci-hcd.4.auto: bus: 'platform': really_probe: bound device to driver xhci-hcd
[  222.032051] typec port0-partner.0: bus: 'typec': __driver_probe_device: matched device with driver typec_displayport
[  222.043845] typec port0-partner.0: bus: 'typec': really_probe: probing driver typec_displayport with device
[  222.054819] typec_displayport port0-partner.0: driver: 'typec_displayport': driver_bound: bound to device
[  222.065547] typec_displayport port0-partner.0: bus: 'typec': really_probe: bound device to driver typec_displayport
[  222.336513] usb 5-1: new full-speed USB device number 2 using xhci-hcd
[  222.493299] usb 5-1: not running at top speed; connect to a high speed hub
[  222.512188] usb 5-1: bus: 'usb': __driver_probe_device: matched device with driver usb
[  222.521057] usb 5-1: bus: 'usb': really_probe: probing driver usb with device
[  222.535340] usb 5-1: driver: 'usb': driver_bound: bound to device
[  222.542185] usb 5-1: bus: 'usb': really_probe: bound device to driver usb
[  224.327221] Console: switching to colour frame buffer device 240x67
[  224.353443] rockchip-drm display-subsystem: [drm] fb0: rockchipdrmfb frame buffer device

[1] -----------
[   23.452524] platform xhci-hcd.4.auto: bus: 'platform': __driver_probe_device: matched device with driver xhci-hcd
[   23.464004] platform xhci-hcd.4.auto: bus: 'platform': really_probe: probing driver xhci-hcd with device
[   23.474654] xhci-hcd xhci-hcd.4.auto: xHCI Host Controller
[   23.480783] xhci-hcd xhci-hcd.4.auto: new USB bus registered, assigned bus number 5
[   23.489401] xhci-hcd xhci-hcd.4.auto: hcc params 0x0220fe64 hci version 0x110 quirks 0x0000808002000010
[   23.499910] xhci-hcd xhci-hcd.4.auto: irq 108, io mem 0xfc000000
[   23.506671] xhci-hcd xhci-hcd.4.auto: xHCI Host Controller
[   23.512790] xhci-hcd xhci-hcd.4.auto: new USB bus registered, assigned bus number 6
[   23.521346] xhci-hcd xhci-hcd.4.auto: Host supports USB 3.0 SuperSpeed
[   23.528805] usb usb5: bus: 'usb': __driver_probe_device: matched device with driver usb
[   23.537771] usb usb5: bus: 'usb': really_probe: probing driver usb with device
[   23.545879] usb 5-0:1.0: bus: 'usb': __driver_probe_device: matched device with driver hub
[   23.555120] usb 5-0:1.0: bus: 'usb': really_probe: probing driver hub with device
[   23.563486] hub 5-0:1.0: USB hub found
[   23.567675] hub 5-0:1.0: 1 port detected
[   23.572138] hub 5-0:1.0: driver: 'hub': driver_bound: bound to device
[   23.579343] hub 5-0:1.0: bus: 'usb': really_probe: bound device to driver hub
[   23.587327] usb usb5: driver: 'usb': driver_bound: bound to device
[   23.594240] usb usb5: bus: 'usb': really_probe: bound device to driver usb
[   23.601942] usb usb6: We don't know the algorithms for LPM for this host, disabling LPM.
[   23.618552] usb usb6: bus: 'usb': __driver_probe_device: matched device with driver usb
[   23.627501] usb usb6: bus: 'usb': really_probe: probing driver usb with device
[   23.635604] usb 6-0:1.0: bus: 'usb': __driver_probe_device: matched device with driver hub
[   23.644841] usb 6-0:1.0: bus: 'usb': really_probe: probing driver hub with device
[   23.653203] hub 6-0:1.0: USB hub found
[   23.657389] hub 6-0:1.0: 1 port detected
[   23.661798] hub 6-0:1.0: driver: 'hub': driver_bound: bound to device
[   23.668998] hub 6-0:1.0: bus: 'usb': really_probe: bound device to driver hub
[   23.676979] usb usb6: driver: 'usb': driver_bound: bound to device
[   23.683886] usb usb6: bus: 'usb': really_probe: bound device to driver usb
[   23.691574] xhci-hcd xhci-hcd.4.auto: driver: 'xhci-hcd': driver_bound: bound to device
[   23.700524] xhci-hcd xhci-hcd.4.auto: bus: 'platform': really_probe: bound device to driver xhci-hcd
[   23.951857] typec port0-partner.0: bus: 'typec': __driver_probe_device: matched device with driver typec_displayport
[   23.963628] typec port0-partner.0: bus: 'typec': really_probe: probing driver typec_displayport with device
[   23.974547] typec_displayport port0-partner.0: driver: 'typec_displayport': driver_bound: bound to device
[   23.985243] typec_displayport port0-partner.0: bus: 'typec': really_probe: bound device to driver typec_displayport
[   24.252358] usb 5-1: new full-speed USB device number 2 using xhci-hcd
[   24.408085] usb 5-1: not running at top speed; connect to a high speed hub
[   24.427935] usb 5-1: bus: 'usb': __driver_probe_device: matched device with driver usb
[   24.441732] usb 5-1: bus: 'usb': really_probe: probing driver usb with device
[   24.462931] usb 5-1: driver: 'usb': driver_bound: bound to device
[   24.475569] usb 5-1: bus: 'usb': really_probe: bound device to driver usb