[PATCH 0/7] i3c: master: some fix and improvemnt for hotjoin

[PATCH 0/7] i3c: master: some fix and improvemnt for hotjoin

[Frank Li]

Signed-off-by: Frank Li <Frank.Li@nxp.com>
---
Frank Li (7):
      i3c: master: Remove i3c_dev_disable_ibi_locked(olddev) on device hotjoin
      i3c: master: Replace hard code 2 with macro I3C_ADDR_SLOT_BITS
      i3c: master: Extend address status bit to 4 and add I3C_ADDR_SLOT_EXT_INIT
      i3c: master: Fix dynamic address leak when 'assigned-address' is present
      i3c: master: Fix miss free init_dyn_addr at i3c_master_put_i3c_addrs()
      i3c: master: svc: use repeat start when IBI WIN happens
      i3c: master: svc: manually emit NACK/ACK for hotjoin

 drivers/i3c/master.c                | 66 +++++++++++++++++++++++--------------
 drivers/i3c/master/svc-i3c-master.c | 44 +++++++++++++++----------
 include/linux/i3c/master.h          |  8 ++++-
 3 files changed, 75 insertions(+), 43 deletions(-)
---
base-commit: 41c196e567fb1ea97f68a2ffb7faab451cd90854
change-id: 20240724-i3c_fix-371bf8fa9e00

Best regards,
---
Frank Li <Frank.Li@nxp.com>


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[PATCH 1/7] i3c: master: Remove i3c_dev_disable_ibi_locked(olddev) on device hotjoin

[Frank Li]

When a new device hotjoins, a new dynamic address is assigned.
i3c_master_add_i3c_dev_locked() identifies that the device was previously
attached to the bus and locates the olddev.

i3c_master_add_i3c_dev_locked()
{
    ...
    olddev = i3c_master_search_i3c_dev_duplicate(newdev);
    ...
    if (olddev) {
        ...
        i3c_dev_disable_ibi_locked(olddev);
        ^^^^^^
        The olddev should not receive any commands on the i3c bus as it
        does not exist and has been assigned a new address. This will
        result in NACK or timeout. So remove it.
    }
}

Fixes: 317bacf960a4 ("i3c: master: add enable(disable) hot join in sys entry")
Signed-off-by: Frank Li <Frank.Li@nxp.com>
---
 drivers/i3c/master.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c
index 7028f03c2c42e..852b32178b722 100644
--- a/drivers/i3c/master.c
+++ b/drivers/i3c/master.c
@@ -2039,10 +2039,8 @@ int i3c_master_add_i3c_dev_locked(struct i3c_master_controller *master,
 			ibireq.max_payload_len = olddev->ibi->max_payload_len;
 			ibireq.num_slots = olddev->ibi->num_slots;
 
-			if (olddev->ibi->enabled) {
+			if (olddev->ibi->enabled)
 				enable_ibi = true;
-				i3c_dev_disable_ibi_locked(olddev);
-			}
 
 			i3c_dev_free_ibi_locked(olddev);
 		}

-- 
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[PATCH 2/7] i3c: master: Replace hard code 2 with macro I3C_ADDR_SLOT_BITS

[Frank Li]

Replace the hardcoded value 2, which indicates 2 bits for I3C address
status, with the predefined macro I3C_ADDR_SLOT_BITS.

Improve maintainability and extensibility of the code.

Signed-off-by: Frank Li <Frank.Li@nxp.com>
---
 drivers/i3c/master.c       | 4 ++--
 include/linux/i3c/master.h | 4 +++-
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c
index 852b32178b722..85c737554c940 100644
--- a/drivers/i3c/master.c
+++ b/drivers/i3c/master.c
@@ -348,7 +348,7 @@ static enum i3c_addr_slot_status
 i3c_bus_get_addr_slot_status(struct i3c_bus *bus, u16 addr)
 {
 	unsigned long status;
-	int bitpos = addr * 2;
+	int bitpos = addr * I3C_ADDR_SLOT_BITS;
 
 	if (addr > I2C_MAX_ADDR)
 		return I3C_ADDR_SLOT_RSVD;
@@ -362,7 +362,7 @@ i3c_bus_get_addr_slot_status(struct i3c_bus *bus, u16 addr)
 static void i3c_bus_set_addr_slot_status(struct i3c_bus *bus, u16 addr,
 					 enum i3c_addr_slot_status status)
 {
-	int bitpos = addr * 2;
+	int bitpos = addr * I3C_ADDR_SLOT_BITS;
 	unsigned long *ptr;
 
 	if (addr > I2C_MAX_ADDR)
diff --git a/include/linux/i3c/master.h b/include/linux/i3c/master.h
index 074f632868d98..4601b6957f799 100644
--- a/include/linux/i3c/master.h
+++ b/include/linux/i3c/master.h
@@ -299,6 +299,8 @@ enum i3c_addr_slot_status {
 	I3C_ADDR_SLOT_STATUS_MASK = 3,
 };
 
+#define I3C_ADDR_SLOT_BITS 2
+
 /**
  * struct i3c_bus - I3C bus object
  * @cur_master: I3C master currently driving the bus. Since I3C is multi-master
@@ -340,7 +342,7 @@ enum i3c_addr_slot_status {
 struct i3c_bus {
 	struct i3c_dev_desc *cur_master;
 	int id;
-	unsigned long addrslots[((I2C_MAX_ADDR + 1) * 2) / BITS_PER_LONG];
+	unsigned long addrslots[((I2C_MAX_ADDR + 1) * I3C_ADDR_SLOT_BITS) / BITS_PER_LONG];
 	enum i3c_bus_mode mode;
 	struct {
 		unsigned long i3c;

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[PATCH 3/7] i3c: master: Extend address status bit to 4 and add I3C_ADDR_SLOT_EXT_INIT

[Frank Li]

Extend the address status bit to 4 and introduce the I3C_ADDR_SLOT_EXT_INIT
macro to indicate that a device prefers a specific address. This is
generally set by the 'assigned-address' in the device tree source (dts)
file.

When an i3c device is removed from the bus, the old address status is set
to FREE, allowing other devices to use the address during hotjoin. The
I3C_ADDR_SLOT_EXT_INIT status indicates that an address is preferred by
some devices. The function i3c_bus_get_free_addr() will first attempt to
use unassigned addresses before searching for assigned addresses of devices
that have been removed from the bus, trying to best match the
'assigned-address'.

Signed-off-by: Frank Li <Frank.Li@nxp.com>
---
 drivers/i3c/master.c       | 43 ++++++++++++++++++++++++++++++++++---------
 include/linux/i3c/master.h |  6 +++++-
 2 files changed, 39 insertions(+), 10 deletions(-)

diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c
index 85c737554c940..4281f673e08d8 100644
--- a/drivers/i3c/master.c
+++ b/drivers/i3c/master.c
@@ -345,7 +345,7 @@ const struct bus_type i3c_bus_type = {
 EXPORT_SYMBOL_GPL(i3c_bus_type);
 
 static enum i3c_addr_slot_status
-i3c_bus_get_addr_slot_status(struct i3c_bus *bus, u16 addr)
+i3c_bus_get_addr_slot_status_ext(struct i3c_bus *bus, u16 addr)
 {
 	unsigned long status;
 	int bitpos = addr * I3C_ADDR_SLOT_BITS;
@@ -356,11 +356,17 @@ i3c_bus_get_addr_slot_status(struct i3c_bus *bus, u16 addr)
 	status = bus->addrslots[bitpos / BITS_PER_LONG];
 	status >>= bitpos % BITS_PER_LONG;
 
-	return status & I3C_ADDR_SLOT_STATUS_MASK;
+	return status & I3C_ADDR_SLOT_EXT_STATUS_MASK;
 }
 
-static void i3c_bus_set_addr_slot_status(struct i3c_bus *bus, u16 addr,
-					 enum i3c_addr_slot_status status)
+static enum i3c_addr_slot_status
+i3c_bus_get_addr_slot_status(struct i3c_bus *bus, u16 addr)
+{
+	return i3c_bus_get_addr_slot_status_ext(bus, addr) & I3C_ADDR_SLOT_STATUS_MASK;
+}
+
+static void i3c_bus_set_addr_slot_status_mask(struct i3c_bus *bus, u16 addr,
+					      enum i3c_addr_slot_status status, int mask)
 {
 	int bitpos = addr * I3C_ADDR_SLOT_BITS;
 	unsigned long *ptr;
@@ -369,11 +375,22 @@ static void i3c_bus_set_addr_slot_status(struct i3c_bus *bus, u16 addr,
 		return;
 
 	ptr = bus->addrslots + (bitpos / BITS_PER_LONG);
-	*ptr &= ~((unsigned long)I3C_ADDR_SLOT_STATUS_MASK <<
-						(bitpos % BITS_PER_LONG));
+	*ptr &= ~((unsigned long)mask << (bitpos % BITS_PER_LONG));
 	*ptr |= (unsigned long)status << (bitpos % BITS_PER_LONG);
 }
 
+static void i3c_bus_set_addr_slot_status(struct i3c_bus *bus, u16 addr,
+					 enum i3c_addr_slot_status status)
+{
+	i3c_bus_set_addr_slot_status_mask(bus, addr, status, I3C_ADDR_SLOT_STATUS_MASK);
+}
+
+static void i3c_bus_set_addr_slot_status_ext(struct i3c_bus *bus, u16 addr,
+					     enum i3c_addr_slot_status status)
+{
+	i3c_bus_set_addr_slot_status_mask(bus, addr, status, I3C_ADDR_SLOT_EXT_STATUS_MASK);
+}
+
 static bool i3c_bus_dev_addr_is_avail(struct i3c_bus *bus, u8 addr)
 {
 	enum i3c_addr_slot_status status;
@@ -388,6 +405,14 @@ static int i3c_bus_get_free_addr(struct i3c_bus *bus, u8 start_addr)
 	enum i3c_addr_slot_status status;
 	u8 addr;
 
+	/* try find an address, which have not pre-allocated by assigned-address */
+	for (addr = start_addr; addr < I3C_MAX_ADDR; addr++) {
+		status = i3c_bus_get_addr_slot_status_ext(bus, addr);
+		if (status == I3C_ADDR_SLOT_FREE)
+			return addr;
+	}
+
+	/* use pre-allocoated by assigned-address because such device was removed at bus*/
 	for (addr = start_addr; addr < I3C_MAX_ADDR; addr++) {
 		status = i3c_bus_get_addr_slot_status(bus, addr);
 		if (status == I3C_ADDR_SLOT_FREE)
@@ -1906,9 +1931,9 @@ static int i3c_master_bus_init(struct i3c_master_controller *master)
 			goto err_rstdaa;
 		}
 
-		i3c_bus_set_addr_slot_status(&master->bus,
-					     i3cboardinfo->init_dyn_addr,
-					     I3C_ADDR_SLOT_I3C_DEV);
+		i3c_bus_set_addr_slot_status_ext(&master->bus,
+						 i3cboardinfo->init_dyn_addr,
+						 I3C_ADDR_SLOT_I3C_DEV | I3C_ADDR_SLOT_EXT_INIT);
 
 		/*
 		 * Only try to create/attach devices that have a static
diff --git a/include/linux/i3c/master.h b/include/linux/i3c/master.h
index 4601b6957f799..c923b76bbc321 100644
--- a/include/linux/i3c/master.h
+++ b/include/linux/i3c/master.h
@@ -284,6 +284,8 @@ enum i3c_bus_mode {
  * @I3C_ADDR_SLOT_I2C_DEV: address is assigned to an I2C device
  * @I3C_ADDR_SLOT_I3C_DEV: address is assigned to an I3C device
  * @I3C_ADDR_SLOT_STATUS_MASK: address slot mask
+ * @I3C_ADDR_SLOT_EXT_INIT: the bit mask display of addresses is preferred by some devices,
+ *			    such as the "assigned-address" in device tree source (dts).
  *
  * On an I3C bus, addresses are assigned dynamically, and we need to know which
  * addresses are free to use and which ones are already assigned.
@@ -297,9 +299,11 @@ enum i3c_addr_slot_status {
 	I3C_ADDR_SLOT_I2C_DEV,
 	I3C_ADDR_SLOT_I3C_DEV,
 	I3C_ADDR_SLOT_STATUS_MASK = 3,
+	I3C_ADDR_SLOT_EXT_STATUS_MASK = 7,
+	I3C_ADDR_SLOT_EXT_INIT = BIT(2),
 };
 
-#define I3C_ADDR_SLOT_BITS 2
+#define I3C_ADDR_SLOT_BITS 4
 
 /**
  * struct i3c_bus - I3C bus object

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[PATCH 4/7] i3c: master: Fix dynamic address leak when 'assigned-address' is present

[Frank Li]

If the DTS contains 'assigned-address', a dynamic address leak occurs
during hotjoin events.

Assume a device have assigned-address 0xb.
  - Device issue Hotjoin
  - Call i3c_master_do_daa()
  - Call driver xxx_do_daa()
  - Call i3c_master_get_free_addr() to get dynamic address 0x9
  - i3c_master_add_i3c_dev_locked(0x9)
  -     expected_dyn_addr  = newdev->boardinfo->init_dyn_addr (0xb);
  -     i3c_master_reattach_i3c_dev(newdev(0xb), old_dyn_addr(0x9));
  -         if (dev->info.dyn_addr != old_dyn_addr &&
                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 0xb != 0x9 -> TRUE
                (!dev->boardinfo ||
                 ^^^^^^^^^^^^^^^ ->  FALSE
                 dev->info.dyn_addr != dev->boardinfo->init_dyn_addr)) {
                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
                 0xb != 0xb      ->  FALSE
                 ...
                 i3c_bus_set_addr_slot_status(&master->bus, old_dyn_addr,
                                                     I3C_ADDR_SLOT_FREE);
		 ^^^
                 This will be skipped. So old_dyn_addr never free
            }

  - i3c_master_get_free_addr() will return increased sequence number.

Remove dev->info.dyn_addr != dev->boardinfo->init_dyn_addr condition check.
dev->info.dyn_addr should be checked before calling this function because
i3c_master_setnewda_locked() has already been called and the target device
has already accepted dyn_addr. It is too late to check if dyn_addr is free
in i3c_master_reattach_i3c_dev().

Add check to ensure expected_dyn_addr is free before
i3c_master_setnewda_locked().

Fixes: cc3a392d69b6 ("i3c: master: fix for SETDASA and DAA process")
Cc: stable@kernel.org
Signed-off-by: Frank Li <Frank.Li@nxp.com>
---
 drivers/i3c/master.c | 15 +++++----------
 1 file changed, 5 insertions(+), 10 deletions(-)

diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c
index 4281f673e08d8..c8eaeada54781 100644
--- a/drivers/i3c/master.c
+++ b/drivers/i3c/master.c
@@ -1531,16 +1531,9 @@ static int i3c_master_reattach_i3c_dev(struct i3c_dev_desc *dev,
 				       u8 old_dyn_addr)
 {
 	struct i3c_master_controller *master = i3c_dev_get_master(dev);
-	enum i3c_addr_slot_status status;
 	int ret;
 
-	if (dev->info.dyn_addr != old_dyn_addr &&
-	    (!dev->boardinfo ||
-	     dev->info.dyn_addr != dev->boardinfo->init_dyn_addr)) {
-		status = i3c_bus_get_addr_slot_status(&master->bus,
-						      dev->info.dyn_addr);
-		if (status != I3C_ADDR_SLOT_FREE)
-			return -EBUSY;
+	if (dev->info.dyn_addr != old_dyn_addr) {
 		i3c_bus_set_addr_slot_status(&master->bus,
 					     dev->info.dyn_addr,
 					     I3C_ADDR_SLOT_I3C_DEV);
@@ -1931,9 +1924,10 @@ static int i3c_master_bus_init(struct i3c_master_controller *master)
 			goto err_rstdaa;
 		}
 
+		/* Not mark as occupied until real device exist in bus */
 		i3c_bus_set_addr_slot_status_ext(&master->bus,
 						 i3cboardinfo->init_dyn_addr,
-						 I3C_ADDR_SLOT_I3C_DEV | I3C_ADDR_SLOT_EXT_INIT);
+						 I3C_ADDR_SLOT_EXT_INIT);
 
 		/*
 		 * Only try to create/attach devices that have a static
@@ -2094,7 +2088,8 @@ int i3c_master_add_i3c_dev_locked(struct i3c_master_controller *master,
 	else
 		expected_dyn_addr = newdev->info.dyn_addr;
 
-	if (newdev->info.dyn_addr != expected_dyn_addr) {
+	if (newdev->info.dyn_addr != expected_dyn_addr &&
+	    i3c_bus_get_addr_slot_status(&master->bus, expected_dyn_addr) == I3C_ADDR_SLOT_FREE) {
 		/*
 		 * Try to apply the expected dynamic address. If it fails, keep
 		 * the address assigned by the master.

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[PATCH 5/7] i3c: master: Fix miss free init_dyn_addr at i3c_master_put_i3c_addrs()

[Frank Li]

if (dev->boardinfo && dev->boardinfo->init_dyn_addr)
                                      ^^^ here check "init_dyn_addr"
	i3c_bus_set_addr_slot_status(&master->bus, dev->info.dyn_addr, ...)
						             ^^^^
							free "dyn_addr"
Fix typo "dyn_addr" by replacing it with "init_dyn_addr".

Cc: stable@kernel.org
Fixes: 3a379bbcea0a ("i3c: Add core I3C infrastructure")
Signed-off-by: Frank Li <Frank.Li@nxp.com>
---
 drivers/i3c/master.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c
index c8eaeada54781..65642e5afdcfb 100644
--- a/drivers/i3c/master.c
+++ b/drivers/i3c/master.c
@@ -1442,7 +1442,7 @@ static void i3c_master_put_i3c_addrs(struct i3c_dev_desc *dev)
 					     I3C_ADDR_SLOT_FREE);
 
 	if (dev->boardinfo && dev->boardinfo->init_dyn_addr)
-		i3c_bus_set_addr_slot_status(&master->bus, dev->info.dyn_addr,
+		i3c_bus_set_addr_slot_status(&master->bus, dev->boardinfo->init_dyn_addr,
 					     I3C_ADDR_SLOT_FREE);
 }
 

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[PATCH 6/7] i3c: master: svc: use repeat start when IBI WIN happens

[Frank Li]

There is a possibility of an IBI WIN occurring when addressing issues, even
when sending CCC commands. Most of the time, returning -EAGAIN is
acceptable, but the case below becomes highly complex.

When a Hotjoin event occurs:
- i3c_master_do_daa()
  - i3c_master_add_i3c_dev_locked()
    - A dynamic address (e.g., 0x9) is already set during DAA.
    - i3c_master_getpid_locked()
      - Another device issues HJ or IBI here. Returning -EAGAIN causes
        failure in adding the new device. However, the dynamic address(0x9)
        has already been assigned to this device. If another device issues
        HJ, it will get this address 0x9 again, causing two devices on the
        bus to use the same dynamic address 0x9.
      - Attempting to send RSTDAA when the first device fails at
        i3c_master_getpid_locked() could also fail when sending RSTDAA for
        the same reason.

According to the I3C spec, address arbitration only happens at START, never
at REPEAT start. Using repeat start when an IBI WIN occurs simplifies this
case, as i3c_master_getpid_locked() will not return an error when another
device tries to send HJ or IBI.

Signed-off-by: Frank Li <Frank.Li@nxp.com>
---
 drivers/i3c/master/svc-i3c-master.c | 36 ++++++++++++++++++------------------
 1 file changed, 18 insertions(+), 18 deletions(-)

diff --git a/drivers/i3c/master/svc-i3c-master.c b/drivers/i3c/master/svc-i3c-master.c
index e80c002991f75..5d19251238ff8 100644
--- a/drivers/i3c/master/svc-i3c-master.c
+++ b/drivers/i3c/master/svc-i3c-master.c
@@ -1099,6 +1099,24 @@ static int svc_i3c_master_xfer(struct svc_i3c_master *master,
 		if (ret)
 			goto emit_stop;
 
+		/*
+		 * According to I3C spec ver 1.1.1, 5.1.2.2.3 Consequence of Controller Starting a
+		 * Frame with I3C Target Address.
+		 *
+		 * The I3C Controller normally should start a Frame, the Address may be arbitrated,
+		 * and so the Controller shall monitor to see whether an In-Band Interrupt request,
+		 * a Controller Role Request (i.e., Secondary Controller requests to become the
+		 * Active Controller), or a Hot-Join Request has been made.
+		 *
+		 * If missed IBIWON check, the wrong data will be return. When IBIWON happen, issue
+		 * repeat start. Address arbitrate only happen at START, never happen at REPEAT
+		 * start.
+		 */
+		if (SVC_I3C_MSTATUS_IBIWON(reg)) {
+			writel(SVC_I3C_MINT_IBIWON, master->regs + SVC_I3C_MSTATUS);
+			continue;
+		}
+
 		if (readl(master->regs + SVC_I3C_MERRWARN) & SVC_I3C_MERRWARN_NACK) {
 			/*
 			 * According to I3C Spec 1.1.1, 11-Jun-2021, section: 5.1.2.2.3.
@@ -1132,24 +1150,6 @@ static int svc_i3c_master_xfer(struct svc_i3c_master *master,
 		}
 	}
 
-	/*
-	 * According to I3C spec ver 1.1.1, 5.1.2.2.3 Consequence of Controller Starting a Frame
-	 * with I3C Target Address.
-	 *
-	 * The I3C Controller normally should start a Frame, the Address may be arbitrated, and so
-	 * the Controller shall monitor to see whether an In-Band Interrupt request, a Controller
-	 * Role Request (i.e., Secondary Controller requests to become the Active Controller), or
-	 * a Hot-Join Request has been made.
-	 *
-	 * If missed IBIWON check, the wrong data will be return. When IBIWON happen, return failure
-	 * and yield the above events handler.
-	 */
-	if (SVC_I3C_MSTATUS_IBIWON(reg)) {
-		ret = -EAGAIN;
-		*actual_len = 0;
-		goto emit_stop;
-	}
-
 	if (rnw)
 		ret = svc_i3c_master_read(master, in, xfer_len);
 	else

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[PATCH 7/7] i3c: master: svc: manually emit NACK/ACK for hotjoin

[Frank Li]

When the address is arbitrated at send address, the hardware can auto-send
NACK if it is an IBI. However, manual emission of NACK/ACK is needed for
hot join or controller request events.

Add an event type check to send out NACK if the event is not an IBI.

Signed-off-by: Frank Li <Frank.Li@nxp.com>
---
 drivers/i3c/master/svc-i3c-master.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/i3c/master/svc-i3c-master.c b/drivers/i3c/master/svc-i3c-master.c
index 5d19251238ff8..36e01d0430747 100644
--- a/drivers/i3c/master/svc-i3c-master.c
+++ b/drivers/i3c/master/svc-i3c-master.c
@@ -1113,7 +1113,15 @@ static int svc_i3c_master_xfer(struct svc_i3c_master *master,
 		 * start.
 		 */
 		if (SVC_I3C_MSTATUS_IBIWON(reg)) {
+			int ibitype = SVC_I3C_MSTATUS_IBITYPE(reg);
+
 			writel(SVC_I3C_MINT_IBIWON, master->regs + SVC_I3C_MSTATUS);
+
+			/* Hardware can't auto emit NACK for hot join and master request */
+			if (ibitype == SVC_I3C_MSTATUS_IBITYPE_HOT_JOIN ||
+			    ibitype == SVC_I3C_MSTATUS_IBITYPE_MASTER_REQUEST)
+				svc_i3c_master_nack_ibi(master);
+
 			continue;
 		}
 

-- 
2.34.1


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