[PATCH v5 1/1] i3c: master: Remove i3c_dev_disable_ibi_locked(olddev) on device hotjoin

From: Frank Li
Date: Tue Oct 01 2024 - 12:25:07 EST


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.
}

i3c_dev_free_ibi_locked(olddev);
^^^^^^^^
This function internally calls i3c_dev_disable_ibi_locked() function
causing to send DISEC command with old Address.

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, update the olddev->ibi->enabled
flag to false to avoid DISEC with OldAddr.
}

Include part of Ravindra Yashvant Shinde's work:
https://lore.kernel.org/linux-i3c/20240820151917.3904956-1-ravindra.yashvant.shinde@xxxxxxx/T/#u

Fixes: 317bacf960a4 ("i3c: master: add enable(disable) hot join in sys entry")
Co-developed-by: Ravindra Yashvant Shinde <ravindra.yashvant.shinde@xxxxxxx>
Signed-off-by: Ravindra Yashvant Shinde <ravindra.yashvant.shinde@xxxxxxx>
Reviewed-by: Miquel Raynal <miquel.raynal@xxxxxxxxxxx>
Signed-off-by: Frank Li <Frank.Li@xxxxxxx>
---
Change from v4 to v5
- none
- just split from big series because need more discussion about dt assign
address.
https://lore.kernel.org/linux-i3c/ZvrAuOBLgi+HtrPD@lizhi-Precision-Tower-5810/T/#t

change from v3 to v4
- merge https://lore.kernel.org/linux-i3c/20240820151917.3904956-1-ravindra.yashvant.shinde@xxxxxxx/T/#u
- add Miquel Raynal review tag
- add Ravindra Yashvant Shinde 's signed-off
---
drivers/i3c/master.c | 13 +++++++++----
1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c
index 7028f03c2c42e..82f031928e413 100644
--- a/drivers/i3c/master.c
+++ b/drivers/i3c/master.c
@@ -2039,11 +2039,16 @@ 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);
- }
-
+ /*
+ * 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, update the olddev->ibi->enabled flag to false
+ * to avoid DISEC with OldAddr.
+ */
+ olddev->ibi->enabled = false;
i3c_dev_free_ibi_locked(olddev);
}
mutex_unlock(&olddev->ibi_lock);
--
2.34.1