Skip to content

driver core: configurable deferred probe timeout#697

Open
apateriy-qcom wants to merge 3 commits into
qualcomm-linux:qcom-6.18.yfrom
apateriy-qcom:6.18.y_deferred_probe_config
Open

driver core: configurable deferred probe timeout#697
apateriy-qcom wants to merge 3 commits into
qualcomm-linux:qcom-6.18.yfrom
apateriy-qcom:6.18.y_deferred_probe_config

Conversation

@apateriy-qcom

@apateriy-qcom apateriy-qcom commented Jun 11, 2026

Copy link
Copy Markdown

With the kernel default of 10s ,we are observing probe deferrals
on Qualcomm platforms where supplier drivers (e.g. regulators, clocks)
are probing late; 60s gives sufficient margin without waiting indefinitely.
On distrokernels, many supplier drivers (clocks, regulators) are built as
modules and are not present in the initrd, especially when the system
waits for mounting the rootfs.
The result is that code using driver_deferred_probe_check_state() hits
the timeout and returns a hard failure rather than deferring
indefinitely like other EPROBE_DEFER paths.

The first patch introduces a Kconfig option,CONFIG_DRIVER_DEFERRED_PROBE_TIMEOUT,
so that a suitable default can be selected at build time without requiring
a kernel command-line override. The second patch extends the deferred_probe_timeout
command-line parameter documentation to clarify that negative values
are treated as an infinite timeout. The third patch sets the Kconfig
default to 60 seconds in the Qualcomm config fragment, which gives
supplier drivers enough margin to probe on Qualcomm platforms without
waiting indefinitely.

Anurag Pateriya (1):
QCLINUX: arm64: configs: qcom: Set DRIVER_DEFERRED_PROBE_TIMEOUT to 60

Hans de Goede (2):
driver core: Make deferred_probe_timeout default a Kconfig option
Documentation: update deferred_probe_timeout cmdline parameter documentation

CRs-Fixed: 4519746

@apateriy-qcom apateriy-qcom force-pushed the 6.18.y_deferred_probe_config branch from 227e19e to 6795936 Compare June 11, 2026 06:13
Hans de Goede and others added 3 commits June 11, 2026 12:59
…option

Code using driver_deferred_probe_check_state() differs from most
EPROBE_DEFER handling in the kernel. Where other EPROBE_DEFER handling
(e.g. clks, gpios and regulators) waits indefinitely for suppliers to
show up, code using driver_deferred_probe_check_state() will fail
after the deferred_probe_timeout.

This is a problem for generic distro kernels which want to support many
boards using a single kernel build. These kernels want as much drivers to
be modular as possible. The initrd also should be as small as possible,
so the initrd will *not* have drivers not needing to get the rootfs.

Combine this with waiting for a full-disk encryption password in
the initrd and it is pretty much guaranteed that the default 10s timeout
will be hit, causing probe() failures when drivers on the rootfs happen
to get modprobe-d before other rootfs modules providing their suppliers.

Make the default timeout configurable from Kconfig to allow distro kernel
configs where many of the supplier drivers are modules to set the default
through Kconfig.

Reviewed-by: Saravana Kannan <saravanak@kernel.org>
Signed-off-by: Hans de Goede <johannes.goede@oss.qualcomm.com>
Link: https://patch.msgid.link/20260314084916.10868-1-johannes.goede@oss.qualcomm.com
[ Drop deferred_probe_timeout documentation change in
  kernel-parameters.txt. - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
…ter documentation

Extend the deferred_probe_timeout cmdline parameter documentation,
documenting that negative values are treated as an infinite timeout value.

Suggested-by: Danilo Krummrich <dakr@kernel.org>
Signed-off-by: Hans de Goede <johannes.goede@oss.qualcomm.com>
Link: https://patch.msgid.link/20260416144144.54547-1-johannes.goede@oss.qualcomm.com
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Set the deferred probe timeout to 60 seconds in the Qualcomm config
fragment.With the kernel default of 10s ,we are observing probe deferrals
on Qualcomm platforms where supplier drivers (e.g. regulators, clocks)
are probing late; 60s gives sufficient margin without waiting indefinitely.

Signed-off-by: Anurag Pateriya <apateriy@qti.qualcomm.com>
@apateriy-qcom apateriy-qcom force-pushed the 6.18.y_deferred_probe_config branch from 6795936 to f24eb44 Compare June 11, 2026 07:31
@qcomlnxci qcomlnxci requested review from a team and yijiyang June 11, 2026 07:38
@qcomlnxci

Copy link
Copy Markdown

Test Matrix

Test Case lemans-evk monaco-evk qcs615-ride qcs6490-rb3gen2 qcs8300-ride qcs9100-ride-r3 x1e80100-crd
BT_FW_KMD_Service ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ◻️
BT_ON_OFF ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ◻️
BT_SCAN ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ◻️
CPUFreq_Validation ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ◻️
CPU_affinity ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ◻️
DSP_AudioPD ✅ Pass ✅ Pass ⚠️ skip ✅ Pass ✅ Pass ⚠️ skip ◻️
Ethernet ⚠️ skip ✅ Pass ⚠️ skip ⚠️ skip ⚠️ skip ⚠️ skip ◻️
Freq_Scaling ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ◻️
GIC ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ◻️
IPA ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ◻️
Interrupts ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ◻️
OpenCV ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ◻️
PCIe ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ◻️
Probe_Failure_Check ❌ Fail ❌ Fail ❌ Fail ❌ Fail ❌ Fail ❌ Fail ◻️
RMNET ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ◻️
UFS_Validation ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ◻️
USBHost ❌ Fail ❌ Fail ❌ Fail ❌ Fail ❌ Fail ❌ Fail ◻️
WiFi_Firmware_Driver ❌ Fail ❌ Fail ✅ Pass ✅ Pass ✅ Pass ✅ Pass ◻️
WiFi_OnOff ✅ Pass ❌ Fail ✅ Pass ✅ Pass ✅ Pass ✅ Pass ◻️
adsp_remoteproc ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ❌ Fail ◻️
cdsp_remoteproc ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ❌ Fail ◻️
gpdsp_remoteproc ✅ Pass ✅ Pass ⚠️ skip ⚠️ skip ✅ Pass ❌ Fail ◻️
hotplug ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ◻️
irq ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ◻️
kaslr ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ◻️
pinctrl ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ◻️
qcom_hwrng ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ◻️
remoteproc ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ❌ Fail ◻️
rngtest ✅ Pass ❌ Fail ✅ Pass ✅ Pass ✅ Pass ✅ Pass ◻️
shmbridge ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ◻️
smmu ❌ Fail ✅ Pass ❌ Fail ✅ Pass ✅ Pass ❌ Fail ◻️
watchdog ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ◻️
wpss_remoteproc ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ◻️

@qcomlnxci

Copy link
Copy Markdown

Test Matrix

Test Case lemans-evk monaco-evk qcs615-ride qcs6490-rb3gen2 qcs8300-ride qcs9100-ride-r3 x1e80100-crd
BT_FW_KMD_Service ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ◻️
BT_ON_OFF ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ◻️
BT_SCAN ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ◻️
CPUFreq_Validation ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ◻️
CPU_affinity ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ◻️
DSP_AudioPD ✅ Pass ✅ Pass ⚠️ skip ✅ Pass ✅ Pass ⚠️ skip ◻️
Ethernet ⚠️ skip ✅ Pass ⚠️ skip ⚠️ skip ⚠️ skip ⚠️ skip ◻️
Freq_Scaling ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ◻️
GIC ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ◻️
IPA ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ◻️
Interrupts ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ◻️
OpenCV ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ◻️
PCIe ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ◻️
Probe_Failure_Check ❌ Fail ❌ Fail ✅ Pass ❌ Fail ❌ Fail ❌ Fail ◻️
RMNET ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ◻️
UFS_Validation ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ◻️
USBHost ❌ Fail ❌ Fail ❌ Fail ❌ Fail ❌ Fail ❌ Fail ◻️
WiFi_Firmware_Driver ❌ Fail ❌ Fail ❌ Fail ✅ Pass ✅ Pass ✅ Pass ◻️
WiFi_OnOff ✅ Pass ❌ Fail ⚠️ skip ✅ Pass ✅ Pass ✅ Pass ◻️
adsp_remoteproc ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ❌ Fail ◻️
cdsp_remoteproc ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ❌ Fail ◻️
gpdsp_remoteproc ✅ Pass ✅ Pass ⚠️ skip ⚠️ skip ✅ Pass ❌ Fail ◻️
hotplug ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ◻️
irq ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ◻️
kaslr ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ◻️
pinctrl ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ◻️
qcom_hwrng ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ◻️
remoteproc ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ❌ Fail ◻️
rngtest ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ◻️
shmbridge ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ◻️
smmu ❌ Fail ✅ Pass ❌ Fail ✅ Pass ✅ Pass ❌ Fail ◻️
watchdog ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ✅ Pass ◻️
wpss_remoteproc ✅ Pass ✅ Pass ⚠️ skip ✅ Pass ✅ Pass ✅ Pass ◻️

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Labels

None yet

Projects

None yet

Development

Successfully merging this pull request may close these issues.

4 participants