[PATCH 5.15.y 4/4] slimbus: qcom-ngd-ctrl: Register callbacks after creating the ngd

[Sasha Levin <sashal@kernel.org>]

From: Bjorn Andersson <bjorn.andersson@oss.qualcomm.com>

[ Upstream commit 2a9d50e9ea406e0c8735938484adc20515ef1b47 ]

When the remoteproc starts in parallel with the NGD driver being probed,
or the remoteproc is already up when the PDR lookup is being registered,
or in the theoretical event that we get an interrupt from the hardware,
these callbacks will operate on uninitialized data. This result in
issues to boot the affected boards.

One such example can be seen in the following fault, where
qcom_slim_ngd_ssr_pdr_notify() schedules work on the NULL ngd_up_work.

[   21.858578] ------------[ cut here ]------------
[   21.858745] WARNING: kernel/workqueue.c:2338 at __queue_work+0x5e0/0x790, CPU#2: kworker/2:2/116
...
[   21.859251] Call trace:
[   21.859255]  __queue_work+0x5e0/0x790 (P)
[   21.859265]  queue_work_on+0x6c/0xf0
[   21.859273]  qcom_slim_ngd_ssr_pdr_notify+0x110/0x150 [slim_qcom_ngd_ctrl]
[   21.859304]  qcom_slim_ngd_ssr_notify+0x24/0x40 [slim_qcom_ngd_ctrl]
[   21.859318]  notifier_call_chain+0xa4/0x230
[   21.859329]  srcu_notifier_call_chain+0x64/0xb8
[   21.859338]  ssr_notify_start+0x40/0x78 [qcom_common]
[   21.859355]  rproc_start+0x130/0x230
[   21.859367]  rproc_boot+0x3d4/0x518
...

Move the enablement of interrupts, and the registration of SSR and PDR
until after the NGD device has been registered.

This could be further refined by moving initialization to the control
driver probe and by removing the platform driver model from the picture.

Fixes: 917809e2280b ("slimbus: ngd: Add qcom SLIMBus NGD driver")
Cc: stable@vger.kernel.org
Reviewed-by: Mukesh Ojha <mukesh.ojha@oss.qualcomm.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@oss.qualcomm.com>
Signed-off-by: Srinivas Kandagatla <srini@kernel.org>
Link: https://patch.msgid.link/20260530204421.116824-6-srini@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/slimbus/qcom-ngd-ctrl.c | 32 ++++++++++++++++++++------------
 1 file changed, 20 insertions(+), 12 deletions(-)

diff --git a/drivers/slimbus/qcom-ngd-ctrl.c b/drivers/slimbus/qcom-ngd-ctrl.c
index 0d118998f00ab8..9584303c5518fb 100644
--- a/drivers/slimbus/qcom-ngd-ctrl.c
+++ b/drivers/slimbus/qcom-ngd-ctrl.c
@@ -1545,17 +1545,13 @@ static int qcom_slim_ngd_ctrl_probe(struct platform_device *pdev)
 	}
 
 	ret = devm_request_irq(dev, res->start, qcom_slim_ngd_interrupt,
-			       IRQF_TRIGGER_HIGH, "slim-ngd", ctrl);
+			       IRQF_TRIGGER_HIGH | IRQF_NO_AUTOEN, "slim-ngd",
+			       ctrl);
 	if (ret) {
 		dev_err(&pdev->dev, "request IRQ failed\n");
 		return ret;
 	}
 
-	ctrl->nb.notifier_call = qcom_slim_ngd_ssr_notify;
-	ctrl->notifier = qcom_register_ssr_notifier("lpass", &ctrl->nb);
-	if (IS_ERR(ctrl->notifier))
-		return PTR_ERR(ctrl->notifier);
-
 	ctrl->dev = dev;
 	ctrl->framer.rootfreq = SLIM_ROOT_FREQ >> 3;
 	ctrl->framer.superfreq =
@@ -1579,23 +1575,35 @@ static int qcom_slim_ngd_ctrl_probe(struct platform_device *pdev)
 	ctrl->pdr = pdr_handle_alloc(slim_pd_status, ctrl);
 	if (IS_ERR(ctrl->pdr)) {
 		dev_err(dev, "Failed to init PDR handle\n");
-		ret = PTR_ERR(ctrl->pdr);
-		goto err_unregister_ssr;
+		return PTR_ERR(ctrl->pdr);
 	}
 
+	ret = of_qcom_slim_ngd_register(dev, ctrl);
+	if (ret)
+		goto err_pdr_release;
+
 	pds = pdr_add_lookup(ctrl->pdr, "avs/audio", "msm/adsp/audio_pd");
 	if (IS_ERR(pds) && PTR_ERR(pds) != -EALREADY) {
 		ret = PTR_ERR(pds);
 		dev_err(dev, "pdr add lookup failed: %d\n", ret);
-		goto err_pdr_release;
+		goto err_unregister_ngd;
 	}
 
-	return of_qcom_slim_ngd_register(dev, ctrl);
+	ctrl->nb.notifier_call = qcom_slim_ngd_ssr_notify;
+	ctrl->notifier = qcom_register_ssr_notifier("lpass", &ctrl->nb);
+	if (IS_ERR(ctrl->notifier)) {
+		ret = PTR_ERR(ctrl->notifier);
+		goto err_unregister_ngd;
+	}
 
+	enable_irq(res->start);
+
+	return 0;
+
+err_unregister_ngd:
+	qcom_slim_ngd_unregister(ctrl);
 err_pdr_release:
 	pdr_handle_release(ctrl->pdr);
-err_unregister_ssr:
-	qcom_unregister_ssr_notifier(ctrl->notifier, &ctrl->nb);
 
 	return ret;
 }
-- 
2.53.0