[PATCH v2 4/7] slimbus: qcom-ngd-ctrl: Register callbacks after creating the ngd

[Bjorn Andersson <bjorn.andersson@oss.qualcomm.com>]

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>
---
 drivers/slimbus/qcom-ngd-ctrl.c | 45 ++++++++++++++++++++++++-----------------
 1 file changed, 26 insertions(+), 19 deletions(-)

diff --git a/drivers/slimbus/qcom-ngd-ctrl.c b/drivers/slimbus/qcom-ngd-ctrl.c
index fd533d5bceb6d7352e8ac6fdce321d3acc285f1e..814ecb01b575984f0951919bba0b8ef4fc64a6dd 100644
--- a/drivers/slimbus/qcom-ngd-ctrl.c
+++ b/drivers/slimbus/qcom-ngd-ctrl.c
@@ -1609,6 +1609,7 @@ static int qcom_slim_ngd_ctrl_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct qcom_slim_ngd_ctrl *ctrl;
+	int irq;
 	int ret;
 	struct pdr_service *pds;
 
@@ -1622,20 +1623,16 @@ static int qcom_slim_ngd_ctrl_probe(struct platform_device *pdev)
 	if (IS_ERR(ctrl->base))
 		return PTR_ERR(ctrl->base);
 
-	ret = platform_get_irq(pdev, 0);
-	if (ret < 0)
-		return ret;
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
 
-	ret = devm_request_irq(dev, ret, qcom_slim_ngd_interrupt,
-			       IRQF_TRIGGER_HIGH, "slim-ngd", ctrl);
+	ret = devm_request_irq(dev, irq, qcom_slim_ngd_interrupt,
+			       IRQF_TRIGGER_HIGH | IRQF_NO_AUTOEN,
+			       "slim-ngd", ctrl);
 	if (ret)
 		return dev_err_probe(&pdev->dev, ret, "request IRQ failed\n");
 
-	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 =
@@ -1657,24 +1654,34 @@ static int qcom_slim_ngd_ctrl_probe(struct platform_device *pdev)
 	init_completion(&ctrl->qmi_up);
 
 	ctrl->pdr = pdr_handle_alloc(slim_pd_status, ctrl);
-	if (IS_ERR(ctrl->pdr)) {
-		ret = dev_err_probe(dev, PTR_ERR(ctrl->pdr),
-				    "Failed to init PDR handle\n");
-		goto err_unregister_ssr;
-	}
+	if (IS_ERR(ctrl->pdr))
+		return dev_err_probe(dev, PTR_ERR(ctrl->pdr), "Failed to init PDR handle\n");
+
+	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 = dev_err_probe(dev, PTR_ERR(pds), "pdr add lookup failed\n");
-		goto err_pdr_release;
+		goto err_unregister_ngd;
+	}
+
+	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;
 	}
 
-	return of_qcom_slim_ngd_register(dev, ctrl);
+	enable_irq(irq);
 
+	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;
 }

-- 
2.51.0