[PATCH 0/7] slimbus: qcom-ngd-ctrl: Fix some race conditions and deadlocks
From: Bjorn Andersson
Date: Tue Mar 10 2026 - 00:09:36 EST
When the qcom-ngd-ctrl driver is probed after the ADSP remoteproc, the
SSR notifier will fire immediately, which results in
qcom_slim_ngd_ssr_pdr_notify() attempting to schedule_work() on an
unitialized work_struct.
The concrete result of this is that my db845c/RB3 now fails to boot 100%
of the time.
In reviewing the problematic code, a few other problems where
discovered, such that platform_driver_unregister() is used to unregister
the child device.
Lastly, with the db845c booting, it was determined that attempting to
stop the ADSP remoteproc causes the slimbus driver to deadlock.
Note that while this solves the problems described above, and unblock
boot as well as restart of the remoteproc, this stack needs more love.
Upon tearing down the slimbus controller (when the ADSP goes down), the
slimbus devices attempts to access their slimbus devices - which is
prevented by the controller being runtime suspended. This results in a
wall of errors in the log, about failing transactions.
Signed-off-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxxxxxxxx>
---
Bjorn Andersson (7):
slimbus: qcom-ngd-ctrl: Fix up platform_driver registration
slimbus: qcom-ngd-ctrl: Fix probe error path ordering
slimbus: qcom-ngd-ctrl: Correct PDR and SSR cleanup ownership
slimbus: qcom-ngd-ctrl: Register callbacks after creating the ngd
slimbus: qcom-ngd-ctrl: Initialize controller resources in controller
slimbus: qcom-ngd-ctrl: Balance pm_runtime enablement for NGD
slimbus: qcom-ngd-ctrl: Avoid ABBA on tx_lock/ctrl->lock
drivers/slimbus/qcom-ngd-ctrl.c | 127 +++++++++++++++++++++++++---------------
1 file changed, 80 insertions(+), 47 deletions(-)
---
base-commit: a0ae2a256046c0c5d3778d1a194ff2e171f16e5f
change-id: 20260211-slim-ngd-dev-74166f29f035
Best regards,
--
Bjorn Andersson <bjorn.andersson@xxxxxxxxxxxxxxxx>