qcom-rtss-can: add recipe for RTSS CAN userspace deamon by q-AnupKulkarni · Pull Request #3104 · qualcomm-linux/meta-qcom

q-AnupKulkarni · 2026-09-09T09:58:16Z

Target milestone: qli-2.1 pull-request freeze

Background

The RTSS subsystem on Qualcomm SoCs includes a dedicated CAN controller that is not directly accessible from the Linux CAN stack. This recipe builds rtss_can, a userspace daemon that bridges that gap by routing traffic between Linux SocketCAN virtual interfaces and RTSS mailbox channels, allowing standard SocketCAN applications to communicate with CAN hardware managed by RTSS. The daemon depends on qcom-rtss-mailbox-umd for the librtss_mailbox interface and on linux-libc-headers for the SocketCAN kernel UAPI headers (linux/can.h, linux/can/raw.h).

PR dependency

#3084

Tracking

#3123

Testing

Default bootup verified on lemans and monaco targets.

Dmitry Baryshkov (lumag)

What was the decision during the RTSS meeting regarding CAN daemon?

Dmitry Baryshkov (lumag)

qcom-rtss-can: align recipe with Yocto conventions

No. Squash your commits. Fix your git setup.

q-AnupKulkarni · 2026-09-10T19:29:37Z

qcom-rtss-can: align recipe with Yocto conventions

No. Squash your commits. Fix your git setup.

Done

q-AnupKulkarni · 2026-09-10T19:54:50Z

What was the decision during the RTSS meeting regarding CAN daemon?

Part of phase-1 deliveries

Phase 1 |
• User-space Mailbox IPC and UMD utilities• User-space CAN ↔ SocketCAN ↔ User-space daemon loopback (vCAN ↔ Mailbox ↔ RTSS)

Tracked here - #3123

Ricardo Salveti (ricardosalveti) · 2026-09-11T00:07:41Z

+LICENSE = "BSD-3-Clause"
+LIC_FILES_CHKSUM = "file://LICENSE.txt;md5=223037c4be0bfc6cf757035432adf983"
+
+DEPENDS = "glib-2.0 qcom-rtss-mailbox-umd linux-libc-headers"


qcom-rtss-mailbox-umd not yet available, moving PR to draft.

Ricardo Salveti (ricardosalveti) · 2026-09-11T00:08:49Z

+DESCRIPTION = "Userspace daemon acting as a gateway between SocketCAN \
+applications and RTSS using the RTSS mailbox UMD libraries."
+
+HOMEPAGE = "https://github.com/qualcomm/rtss-can"


Is it aarch64 only? If so, needs a compatible machine line.

Added for the compatible machines.
COMPATIBLE_MACHINE = "qcs9100-ride-sx|qcs8300-ride-sx|iq-9075-evk|iq-8275-evk"

Ricardo Salveti (ricardosalveti) · 2026-09-11T00:11:03Z

Functional gaps at runtime:

vcan is never available. The daemon needs the vcan module, but no meta-qcom kernel config enables CONFIG_CAN_VCAN, so the RRECOMMENDS is a no-op and the daemon fails at init.
Runtime deps are wrong. It omits the can-gw and rtss-mailbox kernel modules plus iproute2 and kmod for its shell-outs, while the bare can-utils entry is redundant since the only binary used is cangw from can-utils-access.
Nothing starts the daemon. The systemd unit from earlier revisions was dropped and upstream ships none, so the package installs a binary that never runs. Either ship a unit or state in the commit that phase 1 excludes auto-start.

Cleanups:

Dead build inputs. All three EXTRA_OECMAKE flags and the linux-libc-headers DEPENDS do nothing: the include vars duplicate what cmake.bbclass already provides, STAGING_LIBDIR is unreferenced upstream, and the headers come in via glibc.

Dmitry Baryshkov (lumag) · 2026-09-11T00:38:37Z

What was the decision during the RTSS meeting regarding CAN daemon?

Part of phase-1 deliveries

Phase 1 | • User-space Mailbox IPC and UMD utilities• User-space CAN ↔ SocketCAN ↔ User-space daemon loopback (vCAN ↔ Mailbox ↔ RTSS)

Tracked here - #3123

That's not what I meant. What is the agreed ETA for the in-kernel replacement driver?

daemon The RTSS subsystem on Qualcomm SoCs includes a dedicated CAN controller that is not directly accessible from the Linux CAN stack. This recipe builds rtss_can, a userspace daemon that bridges that gap by routing traffic between Linux SocketCAN virtual interfaces and RTSS mailbox channels, allowing standard SocketCAN applications to communicate with CAN hardware managed by RTSS. Signed-off-by: Anup Kulkarni <anup.kulkarni@oss.qualcomm.com>

q-AnupKulkarni · 2026-09-11T22:22:32Z

Functional gaps at runtime:

vcan is never available. The daemon needs the vcan module, but no meta-qcom kernel config enables CONFIG_CAN_VCAN, so the RRECOMMENDS is a no-op and the daemon fails at init.

Runtime deps are wrong. It omits the can-gw and rtss-mailbox kernel modules plus iproute2 and kmod for its shell-outs, while the bare can-utils entry is redundant since the only binary used is cangw from can-utils-access.

Nothing starts the daemon. The systemd unit from earlier revisions was dropped and upstream ships none, so the package installs a binary that never runs. Either ship a unit or state in the commit that phase 1 excludes auto-start.

Cleanups:

Dead build inputs. All three EXTRA_OECMAKE flags and the linux-libc-headers DEPENDS do nothing: the include vars duplicate what cmake.bbclass already provides, STAGING_LIBDIR is unreferenced upstream, and the headers come in via glibc.

Handled it in the updated commit.

q-AnupKulkarni · 2026-09-11T22:24:53Z

What was the decision during the RTSS meeting regarding CAN daemon?

Part of phase-1 deliveries
Phase 1 | • User-space Mailbox IPC and UMD utilities• User-space CAN ↔ SocketCAN ↔ User-space daemon loopback (vCAN ↔ Mailbox ↔ RTSS)
Tracked here - #3123

That's not what I meant. What is the agreed ETA for the in-kernel replacement driver?

Part of phase-2 and phase-3 timelines

Phase 2 | • RTSS Mailbox transition to upstream solution • Socket CAN migration Start | Q1'27
Phase 3 | • Upstream RTSS Mailbox, or RpMsg if throughput requirements are met. If RPMsg does not satisfy performance needs, both solutions will be maintained. • Evaluation of emerging VirtIO-based CAN efforts from the community to align Qualcomm's upstream direction. • CAN upstream-aligned solution | Q2-Q3'27

q-AnupKulkarni requested review from Anuj Mittal (anujm1), Koen Kooi (koenkooi), Dmitry Baryshkov (lumag), Nicolas Dechesne (ndechesne), Ricardo Salveti (ricardosalveti) and Viswanath Kraleti (vkraleti) as code owners September 9, 2026 09:58

Jose Quaresma (quaresmajose) reviewed Sep 9, 2026

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Dmitry Baryshkov (lumag) requested changes Sep 9, 2026

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Dmitry Baryshkov (lumag) requested changes Sep 10, 2026

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q-AnupKulkarni force-pushed the anupkulk/rtss_can branch 3 times, most recently from d10f1db to 5689383 Compare September 10, 2026 19:27

q-AnupKulkarni mentioned this pull request Sep 10, 2026

CAN user space application for RTSS CAN #3123

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Ricardo Salveti (ricardosalveti) reviewed Sep 11, 2026

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Comment thread recipes-support/qcom-rtss-can/qcom-rtss-can_1.0.0.bb Outdated

Ricardo Salveti (ricardosalveti) reviewed Sep 11, 2026

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Comment thread recipes-support/qcom-rtss-can/qcom-rtss-can_1.0.0.bb Outdated

Ricardo Salveti (ricardosalveti) reviewed Sep 11, 2026

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Ricardo Salveti (ricardosalveti) marked this pull request as draft September 11, 2026 00:11

Viswanath Kraleti (vkraleti) added this to the qli-2.1 pull-request freeze milestone Sep 11, 2026

q-AnupKulkarni force-pushed the anupkulk/rtss_can branch from 5689383 to aba9af1 Compare September 11, 2026 22:18

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Target milestone: qli-2.1 pull-request freeze

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q-AnupKulkarni commented Sep 9, 2026 •

edited by ricardosalveti

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