On xiaomi-beryllium and oneplus-enchilada audio does not work reliably with the in-kernel pd-mapper. Deferring the probe solves these issues. Specifically, audio only works reliably with the in-kernel pd-mapper, if the probe succeeds when remoteproc3 triggers the first successful probe. I.e., probes from remoteproc0, 1, and 2 need to be deferred until remoteproc3 has been probed.
Introduce a device specific quirk that lists the first auxdev for which the probe must be executed. Until then, defer probes from other auxdevs.
Fixes: 1ebcde047c54 ("soc: qcom: add pd-mapper implementation") Cc: stable@vger.kernel.org Signed-off-by: Frank Oltmanns frank@oltmanns.dev --- The in-kernel pd-mapper has been causing audio issues on sdm845 devices (specifically, xiaomi-beryllium and oneplus-enchilada). I observed that Stephan’s approach [1] - which defers module probing by blocklisting the module and triggering a later probe - works reliably.
Inspired by this, I experimented with delaying the probe within the module itself by returning -EPROBE_DEFER in qcom_pdm_probe() until a certain time (13.9 seconds after boot, based on ktime_get()) had elapsed. This method also restored audio functionality.
Further logging of auxdev->id in qcom_pdm_probe() led to an interesting discovery: audio only works reliably with the in-kernel pd-mapper when the first successful probe is triggered by remoteproc3. In other words, probes from remoteproc0, 1, and 2 must be deferred until remoteproc3 has been probed.
To address this, I propose introducing a quirk table (which currently only contains sdm845) to defer probing until the correct auxiliary device (remoteproc3) initiates the probe.
I look forward to your feedback.
Thanks, Frank
[1]: https://lore.kernel.org/linux-arm-msm/Zwj3jDhc9fRoCCn6@linaro.org/ --- drivers/soc/qcom/qcom_pd_mapper.c | 43 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 43 insertions(+)
diff --git a/drivers/soc/qcom/qcom_pd_mapper.c b/drivers/soc/qcom/qcom_pd_mapper.c index 154ca5beb47160cc404a46a27840818fe3187420..34b26df665a888ac4872f56e948e73b561ae3b6b 100644 --- a/drivers/soc/qcom/qcom_pd_mapper.c +++ b/drivers/soc/qcom/qcom_pd_mapper.c @@ -46,6 +46,11 @@ struct qcom_pdm_data { struct list_head services; };
+struct qcom_pdm_probe_first_dev_quirk { + const char *name; + u32 id; +}; + static DEFINE_MUTEX(qcom_pdm_mutex); /* protects __qcom_pdm_data */ static struct qcom_pdm_data *__qcom_pdm_data;
@@ -526,6 +531,11 @@ static const struct qcom_pdm_domain_data *x1e80100_domains[] = { NULL, };
+static const struct qcom_pdm_probe_first_dev_quirk first_dev_remoteproc3 = { + .id = 3, + .name = "pd-mapper" +}; + static const struct of_device_id qcom_pdm_domains[] __maybe_unused = { { .compatible = "qcom,apq8016", .data = NULL, }, { .compatible = "qcom,apq8064", .data = NULL, }, @@ -566,6 +576,10 @@ static const struct of_device_id qcom_pdm_domains[] __maybe_unused = { {}, };
+static const struct of_device_id qcom_pdm_defer[] __maybe_unused = { + { .compatible = "qcom,sdm845", .data = &first_dev_remoteproc3, }, + {}, +}; static void qcom_pdm_stop(struct qcom_pdm_data *data) { qcom_pdm_free_domains(data); @@ -637,6 +651,25 @@ static struct qcom_pdm_data *qcom_pdm_start(void) return ERR_PTR(ret); }
+static bool qcom_pdm_ready(struct auxiliary_device *auxdev) +{ + const struct of_device_id *match; + struct device_node *root; + struct qcom_pdm_probe_first_dev_quirk *first_dev; + + root = of_find_node_by_path("/"); + if (!root) + return true; + + match = of_match_node(qcom_pdm_defer, root); + of_node_put(root); + if (!match) + return true; + + first_dev = (struct qcom_pdm_probe_first_dev_quirk *) match->data; + return (auxdev->id == first_dev->id) && !strcmp(auxdev->name, first_dev->name); +} + static int qcom_pdm_probe(struct auxiliary_device *auxdev, const struct auxiliary_device_id *id)
@@ -647,6 +680,15 @@ static int qcom_pdm_probe(struct auxiliary_device *auxdev, mutex_lock(&qcom_pdm_mutex);
if (!__qcom_pdm_data) { + if (!qcom_pdm_ready(auxdev)) { + pr_debug("%s: Deferring probe for device %s (id: %u)\n", + __func__, auxdev->name, auxdev->id); + ret = -EPROBE_DEFER; + goto probe_stop; + } + pr_debug("%s: Probing for device %s (id: %u), starting pdm\n", + __func__, auxdev->name, auxdev->id); + data = qcom_pdm_start();
if (IS_ERR(data)) @@ -659,6 +701,7 @@ static int qcom_pdm_probe(struct auxiliary_device *auxdev,
auxiliary_set_drvdata(auxdev, __qcom_pdm_data);
+probe_stop: mutex_unlock(&qcom_pdm_mutex);
return ret;
--- base-commit: 7f048b202333b967782a98aa21bb3354dc379bbf change-id: 20250205-qcom_pdm_defer-3dc1271d74d9
Best regards,