i3c: master: Remove i3c_dev_disable_ibi_locked(olddev) on device hotjoin

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@nxp.com/T/#u

Fixes: 317bacf960a4 ("i3c: master: add enable(disable) hot join in sys entry")
Co-developed-by: Ravindra Yashvant Shinde <ravindra.yashvant.shinde@nxp.com>
Signed-off-by: Ravindra Yashvant Shinde <ravindra.yashvant.shinde@nxp.com>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Frank Li <Frank.Li@nxp.com>
Link: https://lore.kernel.org/r/20241001162232.223724-1-Frank.Li@nxp.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c
index 5a089be..a1d25c8 100644 (file)
--- a/drivers/i3c/master.c
+++ b/drivers/i3c/master.c
@@ -2088,11 +2088,16 @@ 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);