FAILED: patch "[PATCH] ASoC: qcom: q6apm: Guard callbacks until probe data is ready" failed to apply to 6.1-stable tree

[Sasha Levin <sashal@kernel.org>]

The patch below does not apply to the 6.1-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y
git checkout FETCH_HEAD
git cherry-pick -x ef7062864c0511bba52775d0eb3aa72d886b5f3a
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '20261109201639-failed-6.1-ef7062864c05@kernel.org' --subject-prefix 'PATCH 6.1.y' 'HEAD^..'

Thanks,
Sasha

------------------ original commit in Linus's tree ------------------

From ef7062864c0511bba52775d0eb3aa72d886b5f3a Mon Sep 17 00:00:00 2001
From: Mohit Sharma <mohit.sharma@oss.qualcomm.com>
Date: Thu, 22 Oct 2026 20:11:29 +0530
Subject: [PATCH] ASoC: qcom: q6apm: Guard callbacks until probe data is ready

The GPR bus needs to make response callbacks available before invoking a
client probe because clients can issue synchronous commands from probe.
This creates a short interval where a callback can run before the client
has published its private data.

Make q6apm publish its driver data only after all callback-visible state
has been initialized. Have the q6apm and q6prm callbacks ignore packets
received before driver data is available.

Fixes: ec1471a898cc ("soc: qcom: apr: Add GPR support")
Cc: stable@vger.kernel.org
Co-developed-by: Ajay Kumar Nandam <ajay.nandam@oss.qualcomm.com>
Signed-off-by: Ajay Kumar Nandam <ajay.nandam@oss.qualcomm.com>
Signed-off-by: Mohit Sharma <mohit.sharma@oss.qualcomm.com>
Link: https://patch.msgid.link/20261022144130.2443667-2-mohit.sharma@oss.qualcomm.com
Signed-off-by: Mark Brown <broonie@kernel.org>
---
 sound/soc/qcom/qdsp6/q6apm.c | 6 ++++--
 sound/soc/qcom/qdsp6/q6prm.c | 3 +++
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/sound/soc/qcom/qdsp6/q6apm.c b/sound/soc/qcom/qdsp6/q6apm.c
index bed3b64e83102..8e3314a2738c0 100644
--- a/sound/soc/qcom/qdsp6/q6apm.c
+++ b/sound/soc/qcom/qdsp6/q6apm.c
@@ -890,8 +890,6 @@ static int apm_probe(gpr_device_t *gdev)
 	if (!apm)
 		return -ENOMEM;
 
-	dev_set_drvdata(dev, apm);
-
 	mutex_init(&apm->lock);
 	apm->dev = dev;
 	apm->gdev = gdev;
@@ -905,6 +903,7 @@ static int apm_probe(gpr_device_t *gdev)
 
 	idr_init(&apm->modules_idr);
 
+	dev_set_drvdata(dev, apm);
 	g_apm = apm;
 
 	q6apm_get_apm_state(apm);
@@ -949,6 +948,9 @@ static int apm_callback(const struct gpr_resp_pkt *data, void *priv, int op)
 	const struct gpr_hdr *hdr = &data->hdr;
 	int graph_id, is_pos_buf;
 
+	if (!apm)
+		return 0;
+
 	result = data->payload;
 
 	switch (hdr->opcode) {
diff --git a/sound/soc/qcom/qdsp6/q6prm.c b/sound/soc/qcom/qdsp6/q6prm.c
index 2042ff1e8ff1b..5c927ebd81f41 100644
--- a/sound/soc/qcom/qdsp6/q6prm.c
+++ b/sound/soc/qcom/qdsp6/q6prm.c
@@ -194,6 +194,9 @@ static int prm_callback(const struct gpr_resp_pkt *data, void *priv, int op)
 	const struct gpr_ibasic_rsp_result_t *result;
 	const struct gpr_hdr *hdr = &data->hdr;
 
+	if (!prm)
+		return 0;
+
 	switch (hdr->opcode) {
 	case PRM_CMD_RSP_REQUEST_HW_RSC:
 	case PRM_CMD_RSP_RELEASE_HW_RSC:
-- 
2.53.0