FAILED: patch "[PATCH] mailbox: qcom-ipcc: fix duplicate channel allocation across" failed to apply to 5.10-stable tree

FAILED: patch "[PATCH] mailbox: qcom-ipcc: fix duplicate channel allocation across" failed to apply to 5.10-stable tree

[gregkh]

The patch below does not apply to the 5.10-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-5.10.y
git checkout FETCH_HEAD
git cherry-pick -x 66c7bcad72430a02c860521031350b84b31ad9a8
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026090342-wildfire-scrambler-d994@gregkh' --subject-prefix 'PATCH 5.10.y' 'HEAD^..'

Possible dependencies:



thanks,

greg k-h

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

From 66c7bcad72430a02c860521031350b84b31ad9a8 Mon Sep 17 00:00:00 2001
From: Anup Vishwakarma <anup.vishwakarma@oss.qualcomm.com>
Date: Wed, 5 Aug 2026 14:34:07 +0530
Subject: [PATCH] mailbox: qcom-ipcc: fix duplicate channel allocation across
 holes

The IPCC of_xlate() both scans for a free mailbox channel and checks
for duplicate references to the same underlying IPCC channel. When a
channel has been shutdown it might have left a hole in the channel
list, which would terminate the search without considering duplicates
later in the list.

Continue the traversal of the channel list to detect and reject
duplicates, while keeping track of the first free channel.

Fixes: d6fbfdbc1274 ("mailbox: qcom-ipcc: Fix IPCC mbox channel exhaustion")
Cc: stable@vger.kernel.org
Signed-off-by: Anup Vishwakarma <anup.vishwakarma@oss.qualcomm.com>
Signed-off-by: Jassi Brar <jassisinghbrar@gmail.com>

diff --git a/drivers/mailbox/qcom-ipcc.c b/drivers/mailbox/qcom-ipcc.c
index e5ebb4a237ff..185b63f724d4 100644
--- a/drivers/mailbox/qcom-ipcc.c
+++ b/drivers/mailbox/qcom-ipcc.c
@@ -167,7 +167,7 @@ static struct mbox_chan *qcom_ipcc_mbox_xlate(struct mbox_controller *mbox,
 {
 	struct qcom_ipcc *ipcc = to_qcom_ipcc(mbox);
 	struct qcom_ipcc_chan_info *mchan;
-	struct mbox_chan *chan;
+	struct mbox_chan *chan, *free_chan = NULL;
 	struct device *dev;
 	int chan_id;
 
@@ -180,16 +180,21 @@ static struct mbox_chan *qcom_ipcc_mbox_xlate(struct mbox_controller *mbox,
 		chan = &ipcc->chans[chan_id];
 		mchan = chan->con_priv;
 
-		if (!mchan)
-			break;
-		else if (mchan->client_id == ph->args[0] &&
-				mchan->signal_id == ph->args[1])
+		if (!mchan) {
+			/* Keep scanning past holes to reject duplicate channel requests. */
+			if (!free_chan)
+				free_chan = chan;
+		} else if (mchan->client_id == ph->args[0] &&
+				mchan->signal_id == ph->args[1]) {
 			return ERR_PTR(-EBUSY);
+		}
 	}
 
-	if (chan_id >= mbox->num_chans)
+	if (!free_chan)
 		return ERR_PTR(-EBUSY);
 
+	chan = free_chan;
+
 	mchan = devm_kzalloc(dev, sizeof(*mchan), GFP_KERNEL);
 	if (!mchan)
 		return ERR_PTR(-ENOMEM);

[PATCH 5.10.y 1/2] mailbox: qcom-ipcc: Dynamic alloc for channel arrangement

[Sasha Levin]

From: Huang Yiwei <quic_hyiwei@quicinc.com>

[ Upstream commit e9d50e4b4d04165097a71e20e0a77e7ad7053dd0 ]

Dynamic alloc for channel arrangement instead of static alloced
array, it is more flexible and can reduce memory usage.

Signed-off-by: Huang Yiwei <quic_hyiwei@quicinc.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
Stable-dep-of: 66c7bcad7243 ("mailbox: qcom-ipcc: fix duplicate channel allocation across holes")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/mailbox/qcom-ipcc.c | 90 ++++++++++++++++++++++++++++---------
 1 file changed, 69 insertions(+), 21 deletions(-)

diff --git a/drivers/mailbox/qcom-ipcc.c b/drivers/mailbox/qcom-ipcc.c
index 584700cd15855..1bc5382c8fc81 100644
--- a/drivers/mailbox/qcom-ipcc.c
+++ b/drivers/mailbox/qcom-ipcc.c
@@ -13,8 +13,6 @@
 
 #include <dt-bindings/mailbox/qcom-ipcc.h>
 
-#define IPCC_MBOX_MAX_CHAN		48
-
 /* IPCC Register offsets */
 #define IPCC_REG_SEND_ID		0x0c
 #define IPCC_REG_RECV_ID		0x10
@@ -52,9 +50,10 @@ struct qcom_ipcc {
 	struct device *dev;
 	void __iomem *base;
 	struct irq_domain *irq_domain;
-	struct mbox_chan chan[IPCC_MBOX_MAX_CHAN];
-	struct qcom_ipcc_chan_info mchan[IPCC_MBOX_MAX_CHAN];
+	struct mbox_chan *chans;
+	struct qcom_ipcc_chan_info *mchan;
 	struct mbox_controller mbox;
+	int num_chans;
 	int irq;
 };
 
@@ -166,25 +165,37 @@ static struct mbox_chan *qcom_ipcc_mbox_xlate(struct mbox_controller *mbox,
 	struct qcom_ipcc *ipcc = to_qcom_ipcc(mbox);
 	struct qcom_ipcc_chan_info *mchan;
 	struct mbox_chan *chan;
-	unsigned int i;
+	struct device *dev;
+	int chan_id;
+
+	dev = ipcc->dev;
 
 	if (ph->args_count != 2)
 		return ERR_PTR(-EINVAL);
 
-	for (i = 0; i < IPCC_MBOX_MAX_CHAN; i++) {
-		chan = &ipcc->chan[i];
-		if (!chan->con_priv) {
-			mchan = &ipcc->mchan[i];
-			mchan->client_id = ph->args[0];
-			mchan->signal_id = ph->args[1];
-			chan->con_priv = mchan;
-			break;
-		}
+	for (chan_id = 0; chan_id < mbox->num_chans; chan_id++) {
+		chan = &ipcc->chans[chan_id];
+		mchan = chan->con_priv;
 
-		chan = NULL;
+		if (!mchan)
+			break;
+		else if (mchan->client_id == ph->args[0] &&
+				mchan->signal_id == ph->args[1])
+			return ERR_PTR(-EBUSY);
 	}
 
-	return chan ?: ERR_PTR(-EBUSY);
+	if (chan_id >= mbox->num_chans)
+		return ERR_PTR(-EBUSY);
+
+	mchan = devm_kzalloc(dev, sizeof(*mchan), GFP_KERNEL);
+	if (!mchan)
+		return ERR_PTR(-ENOMEM);
+
+	mchan->client_id = ph->args[0];
+	mchan->signal_id = ph->args[1];
+	chan->con_priv = mchan;
+
+	return chan;
 }
 
 static const struct mbox_chan_ops ipcc_mbox_chan_ops = {
@@ -192,15 +203,49 @@ static const struct mbox_chan_ops ipcc_mbox_chan_ops = {
 	.shutdown = qcom_ipcc_mbox_shutdown,
 };
 
-static int qcom_ipcc_setup_mbox(struct qcom_ipcc *ipcc)
+static int qcom_ipcc_setup_mbox(struct qcom_ipcc *ipcc,
+				struct device_node *controller_dn)
 {
+	struct of_phandle_args curr_ph;
+	struct device_node *client_dn;
 	struct mbox_controller *mbox;
 	struct device *dev = ipcc->dev;
+	int i, j, ret;
+
+	/*
+	 * Find out the number of clients interested in this mailbox
+	 * and create channels accordingly.
+	 */
+	ipcc->num_chans = 0;
+	for_each_node_with_property(client_dn, "mboxes") {
+		if (!of_device_is_available(client_dn))
+			continue;
+		i = of_count_phandle_with_args(client_dn,
+						"mboxes", "#mbox-cells");
+		for (j = 0; j < i; j++) {
+			ret = of_parse_phandle_with_args(client_dn, "mboxes",
+						"#mbox-cells", j, &curr_ph);
+			of_node_put(curr_ph.np);
+			if (!ret && curr_ph.np == controller_dn) {
+				ipcc->num_chans++;
+				break;
+			}
+		}
+	}
+
+	/* If no clients are found, skip registering as a mbox controller */
+	if (!ipcc->num_chans)
+		return 0;
+
+	ipcc->chans = devm_kcalloc(dev, ipcc->num_chans,
+					sizeof(struct mbox_chan), GFP_KERNEL);
+	if (!ipcc->chans)
+		return -ENOMEM;
 
 	mbox = &ipcc->mbox;
 	mbox->dev = dev;
-	mbox->num_chans = IPCC_MBOX_MAX_CHAN;
-	mbox->chans = ipcc->chan;
+	mbox->num_chans = ipcc->num_chans;
+	mbox->chans = ipcc->chans;
 	mbox->ops = &ipcc_mbox_chan_ops;
 	mbox->of_xlate = qcom_ipcc_mbox_xlate;
 	mbox->txdone_irq = false;
@@ -233,7 +278,7 @@ static int qcom_ipcc_probe(struct platform_device *pdev)
 	if (!ipcc->irq_domain)
 		return -ENOMEM;
 
-	ret = qcom_ipcc_setup_mbox(ipcc);
+	ret = qcom_ipcc_setup_mbox(ipcc, pdev->dev.of_node);
 	if (ret)
 		goto err_mbox;
 
@@ -241,7 +286,7 @@ static int qcom_ipcc_probe(struct platform_device *pdev)
 			       IRQF_TRIGGER_HIGH, "ipcc", ipcc);
 	if (ret < 0) {
 		dev_err(&pdev->dev, "Failed to register the irq: %d\n", ret);
-		goto err_mbox;
+		goto err_req_irq;
 	}
 
 	enable_irq_wake(ipcc->irq);
@@ -249,6 +294,9 @@ static int qcom_ipcc_probe(struct platform_device *pdev)
 
 	return 0;
 
+err_req_irq:
+	if (ipcc->num_chans)
+		mbox_controller_unregister(&ipcc->mbox);
 err_mbox:
 	irq_domain_remove(ipcc->irq_domain);
 
-- 
2.53.0

[PATCH 5.10.y 2/2] mailbox: qcom-ipcc: fix duplicate channel allocation across holes

[Sasha Levin]

From: Anup Vishwakarma <anup.vishwakarma@oss.qualcomm.com>

[ Upstream commit 66c7bcad72430a02c860521031350b84b31ad9a8 ]

The IPCC of_xlate() both scans for a free mailbox channel and checks
for duplicate references to the same underlying IPCC channel. When a
channel has been shutdown it might have left a hole in the channel
list, which would terminate the search without considering duplicates
later in the list.

Continue the traversal of the channel list to detect and reject
duplicates, while keeping track of the first free channel.

Fixes: d6fbfdbc1274 ("mailbox: qcom-ipcc: Fix IPCC mbox channel exhaustion")
Cc: stable@vger.kernel.org
Signed-off-by: Anup Vishwakarma <anup.vishwakarma@oss.qualcomm.com>
Signed-off-by: Jassi Brar <jassisinghbrar@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/mailbox/qcom-ipcc.c | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/drivers/mailbox/qcom-ipcc.c b/drivers/mailbox/qcom-ipcc.c
index 1bc5382c8fc81..1ab8b25955a05 100644
--- a/drivers/mailbox/qcom-ipcc.c
+++ b/drivers/mailbox/qcom-ipcc.c
@@ -164,7 +164,7 @@ static struct mbox_chan *qcom_ipcc_mbox_xlate(struct mbox_controller *mbox,
 {
 	struct qcom_ipcc *ipcc = to_qcom_ipcc(mbox);
 	struct qcom_ipcc_chan_info *mchan;
-	struct mbox_chan *chan;
+	struct mbox_chan *chan, *free_chan = NULL;
 	struct device *dev;
 	int chan_id;
 
@@ -177,16 +177,21 @@ static struct mbox_chan *qcom_ipcc_mbox_xlate(struct mbox_controller *mbox,
 		chan = &ipcc->chans[chan_id];
 		mchan = chan->con_priv;
 
-		if (!mchan)
-			break;
-		else if (mchan->client_id == ph->args[0] &&
-				mchan->signal_id == ph->args[1])
+		if (!mchan) {
+			/* Keep scanning past holes to reject duplicate channel requests. */
+			if (!free_chan)
+				free_chan = chan;
+		} else if (mchan->client_id == ph->args[0] &&
+				mchan->signal_id == ph->args[1]) {
 			return ERR_PTR(-EBUSY);
+		}
 	}
 
-	if (chan_id >= mbox->num_chans)
+	if (!free_chan)
 		return ERR_PTR(-EBUSY);
 
+	chan = free_chan;
+
 	mchan = devm_kzalloc(dev, sizeof(*mchan), GFP_KERNEL);
 	if (!mchan)
 		return ERR_PTR(-ENOMEM);
-- 
2.53.0