2024 Display Next Hackfest

About

The Display Next Hackfest is an event where talented developers will gather to explore the latest technologies and trends in the Linux Display Stack. It has an unconference format where participants propose topics for presenting, roadmapping, discussing and examining together. It aims to unblock bottlenecks, design solutions, raise pitfalls and accommodate the needs of each layer of the display stack. Participants should feel free to propose any topic which interests them. Some topics from the previous edition include: HDR and color management, frame timing and variable refresh rate (VRR), atomic flips, testing and CI, etc.

Plans and Goals

1. Keep moving! Continue your work on upstream design, implementation and documentation until the hackfest.
2. “Are you okay with that?” Present the current status of your work, explain decisions, concerns and results. Let’s compromise.
3. Share your pains. What is well aligned with the generic approach? What is not (singularities) and how can we find room for it? Whatever your doubts, we resolve them together!
4. “Something went wrong.” Share failing tests or inconsistent results. Let’s take a look together and find how to overcome them!

The hackfest will last three days following a “Unconference” format. Check the event timetable and agenda below.

* Information about the previous year can be found on Shell Display Next 2023 wiki.

Timetable

Time/Date	Tue, May 14	Wed, May 15	Thu, May 16
09:00 - 9:30	Walk to Igalia HQ	Walk to Igalia HQ	Walk to Igalia HQ
09:30 - 10:10	Welcome! (Igalia HQ & participants intro)	Recap & Planning	Recap & Planning
10:10 - 11:40	Hacking time	Hacking time	Hacking time
11:40 - 12:00	20-min break	20-min break	20-min break
12:00 - 13:30	Hacking time	Hacking time	Hacking time
13:30 - 15:10	Lunch*	Lunch*	Lunch*
15:10 - 16:40	Hacking time	Hacking time	Wrapping-up
16:40 - 17:00	20-min break	20-min break
17:00 - 18:30	Hacking time	Hacking time	Social Activity
20:30	Hackfest Dinner (sponsored by Igalia)

* Food offered to participants in the office.

Agenda

KMS Color/HDR

• Proposal with new DRM object type:
  • Presentation of GPU-vendors features;
  • Status-update of plane color management pipeline per vendor on Linux;
• HDR/Color Use-cases:
  • Google/ChromeOS GFX view about HDR/per-plane color management and VKMS;
• Post-blending Color Pipeline.

Color/HDR testing/CI

• VKMS status-update;
• Chamelium boards, video capture.

Wayland

• color-management protocol status-update;
• color-representation and video playback.

Display control

• HDR signalling status-update;
• backlight status-update;
• EDID and DDC/CI.

Multi-plane support in compositors

• Underlay, overlay, or mixed strategy for video and gaming use-cases;
• KMS Plane UAPI to simplify the plane arrangement problem;
• Shared plane arrangement algorithm desired.

Frame timing and VRR

• Frame timing:
  • Limitations of uAPI;
  • Current user space solutions;
  • Brainstorm better uAPI;
• Cursor/overlay plane updates with VRR;
• KMS commit and buffer-readiness deadlines;

Power Saving vs Color/Latency

• ABM (adaptive backlight management);
• PSR1 latencies;
• Power optimization vs color accuracy/latency requirements.

Content-Adaptive Scaling & Sharpening

• Content Adaptive Scalers on display hardware;
• New drm_colorop for content adaptive scaling;
• Proprietary algorithms.

Display Mux

• Laptop muxes for switching of the embedded panel between the integrated GPU and the discrete GPU;
• Seamless/atomic hand-off between drivers on Linux desktops.

Real time scheduling & async KMS API

• Potential benefits: lower latency input feedback, better VRR handling, buffer synchronization, etc.
• Issues around “async” uAPI usage and async-call handling.

More details here.

Participants

See the list of participants here.

✈︎
Fly to A Coruña (recommended)

A Coruña Airport (LCG) is connected to Geneva, London/Gatwick, Milan, Barcelona and Madrid.

To get to the venue from A Coruña Airport:

• Taxi - 15 min - Airport taxi stand.

  Fare: The cost is usually 15-20€.
  Payment method: Cash or credit card (ask beforehand).

• Bus - 20 min - Airport bus stop.

  Use the Airport-City Center Bus line (Line 4051 Centro da cidade - Aeroporto.).
  Stop at "Estación de Autobuses".
  On the way back you should pick the bus on the other side of the road, in the gas station ("gasolinera").
  Fare: 1.55€ (0.88€ with metropolitan card).
  Payment method: Only cash, buy on the bus.
  From bus station to Igalia office (8 min walk).
  Schedules:

  • On working days, both from A Coruña and from the airport, buses run from 7:15 to 21.45 every half hour. Early bus at 05:00 (from city center) and 06:15. Night bus at 23:15, 23:30 and 00:30.
  • On Saturdays, Sundays and bank-holidays they leave from A Coruña every hour from 6:30 to 23:30, and from the airport from 6:00 to 23:00 also every hour. Early bus to the airport at 05:00.

✈︎
Fly to Santiago

Santiago Airport (SCQ) is connected to Madrid, Barcelona, Amsterdam/Schiphol, Basel/Mulhouse, Barcelona, Brussels, Dublin, Edinburg, Frankfurt, Memmingen, Geneva, London, Milan/Bergamo, Bologna, Paris, Bordeaux, Marsella and Zurich.

About 50km from to Coruña, it's a good option if you have a direct flight, but requires to go to A Coruña from there.

To get to the venue from Santiago Airport:

• Bus/Taxi + Train - 40 min (bus)/20 min (taxi) + 30 min (train)

  Bus from Santiago Airport to train station - Airport bus stop
  Stop at Train Station ("Hórreo (estación)" "Estación de Tren/Ferrocarril").
  Fare: 1€.
  Payment method: Cash.
  Schedules.

  Taxi from Santiago Airport to train station - Airport taxi stand.
  Fare: Fixed fare 21€.
  Payment method: Cash or credit card (ask beforehand).

  Train from Santiago to A Coruña
  Fare: Depends on the schedule.
  Payment method: Cash or credit card buying tickets at the train station. Or buy them in advance at refe.com or thetrainline.com (Warning: On Sunday's afternoons/evengins or Monday's mornings the train can be full so booking in advance is recommended).
  From A Coruña train station to Igalia office (11 min walk).

• Taxi - 45 min

  Direct taxi from Santiago Airport to A Coruña - Airport taxi stand.
  Fare: Around 80€.
  Payment method: Cash, credit card (ask beforehand), or book in advance at taxigalicia.com.

• Direct bus - 60 min

  Bus from Santiago Airport to A Coruña - Bus from Santiago Airport to A Coruña Bus Station ("Estación de Autobuses").
  Fare: 6.70€.
  Payment method: Cash or online (in Spanish).
  Schedules (quite limited).
  From Bus Station to Igalia office (8 min walk).

✈︎
Fly to Porto (Portugal)

Porto Airport (OPO) is connected to several big cities like: New York, Toronto, Montreal, Rio, Sao Paulo, Londo, Frankfurt, Helsinki, Paris.

To get to the venue from Porto Airport:

• Rent a car - 3 hours
  Porto airport is about 300km away from A Coruña.
• Bus - 5 hours
  Fare: 50€.
  Payment method: Buy ticket online.
  From bus station to Igalia office (8 min walk).

🚌
Bus

Bus connections to A Coruña are available from all major cities in Spain.

• Bus: Bus tickets to get to A Coruña are available from ALSA amongst other carriers.
  From Bus Station to Igalia office (8 min walk).

🚆
Train

Train connections to A Coruña are available from all major cities in Spain.

• Train: Train tickets to get to A Coruña are available from Renfe or thetrainline.com.
  From train station to Igalia office (11 min walk).

🚗
Car

It is also possible to drive to A Coruña.

🏨
Accommodation

There are a bunch of nice hotels around the event venue (Palexco).

Options:

• We recommend staying in Hotel Avenida (Budget), which is a five minute walk from Igalia’s office and is offering a discounted rate for hackfest attendees. Please, contact us for booking with special rates - let us know the room size (single or double) and name(s) under which we should book the room.
• Hotel Attica21 Coruña (First class. 15 min walking)
• AC by Marriot (First class. 15 min walking)

🏥
Covid rules

The 2024 Display Next Hackfest organizers continuously monitor local guidelines and regulations related to COVID-19. The changeable nature of the pandemic means that regular updates to this policy may be necessary. We will inform registered participants about any substantial changes to this document.

By attending, you agree to abide by applicable Spanish regulations for indoor activities and the 2024 Display Next Hackfest health & safety rules, and to conduct yourself in accordance with all provided instructions. This will include, but is not limited to:

• refraining from coming to the event if you have COVID-19 or its symptoms, or if you are required to be in self-isolation or quarantine by COVID-19 regulations in Spain or at the location you are travelling from;
• complying with the prevailing mask-wearing policy communicated at the event; Even if when regulations have removed the obligation to wear masks, the organization establishes masks as recommended indoors;
• following instructions on physical distancing and crowd circulation at the event;
• observing good hand-washing and hygiene etiquette.

More information can be found at: sanidad.gob.es.

💡
Notes

• Usual timetables. Lunch time: 13:00 - 15:30. Dinner time: 20:30 - 22:30. Note that you won't be able to find a restaurant open for lunch at 12:00 or for dinner at 18:00, neither at 19:00; thus you might want to start your day a bit "later" than usual. Main reason behind this is that A Coruña is in the same timezone than central Europe, and sunrise and sunset times are somehow shifted with regard to common standards in other parts of the world.
• Language. The official languages in A Coruña are Galician and Spanish. Not everybody is able to understand or speak English (in the bus, taxi, hotel, etc). The 2024 Display Next Hackfest is run in English.
• Climate. A Coruña has a climate heavily moderated by the Atlantic Ocean. Average temperatures are around 10ºC (51ºF) in winter and 19ºC (66ºF) during summer. (See more info at Wikipedia).
• Tourism. Tourism A Coruña website.