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Message-ID: <20240820151917.3904956-1-ravindra.yashvant.shinde@nxp.com>
Date: Tue, 20 Aug 2024 20:49:17 +0530
From: Ravindra Yashvant Shinde <ravindra.yashvant.shinde@....com>
To: Alexandre Belloni <alexandre.belloni@...tlin.com>,
linux-i3c@...ts.infradead.org (moderated list:I3C SUBSYSTEM),
linux-kernel@...r.kernel.org (open list)
Cc: imx@...ts.linux.dev,
Frank.Li@....com,
Ravindra Yashvant Shinde <ravindra.yashvant.shinde@....com>
Subject: [PATCH v2 1/1] i3c: master: Avoid sending DISEC command with old device address.
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) {
enable_ibi = true;
...
}
i3c_dev_free_ibi_locked(olddev);
^^^^^^^^
This function internally calls i3c_dev_disable_ibi_locked(addr)
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.
...
}
Signed-off-by: Ravindra Yashvant Shinde <ravindra.yashvant.shinde@....com>
---
change from v1 to v2
- Fixed the author name.
- Unconditional set to the false & added some comments.
---
drivers/i3c/master.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c
index 7028f03c2c42..0dd8d1c28d58 100644
--- a/drivers/i3c/master.c
+++ b/drivers/i3c/master.c
@@ -2043,7 +2043,14 @@ int i3c_master_add_i3c_dev_locked(struct i3c_master_controller *master,
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);
--
2.46.0
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