6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Frank Li <Frank.Li@xxxxxxx>
commit 3b2ac810d86eb96e882db80a3320a3848b133208 upstream.
svc_i3c_master_do_daa() {
...
for (i = 0; i < dev_nb; i++) {
ret = i3c_master_add_i3c_dev_locked(m, addrs[i]);
if (ret)
goto rpm_out;
}
}
If two devices (A and B) are detected in DAA and address 0xa is assigned to
device A and 0xb to device B, a failure in i3c_master_add_i3c_dev_locked()
for device A (addr: 0xa) could prevent device B (addr: 0xb) from being
registered on the bus. The I3C stack might still consider 0xb a free
address. If a subsequent Hotjoin occurs, 0xb might be assigned to Device A,
causing both devices A and B to use the same address 0xb, violating the I3C
specification.
The return value for i3c_master_add_i3c_dev_locked() should not be checked
because subsequent steps will scan the entire I3C bus, independent of
whether i3c_master_add_i3c_dev_locked() returns success.
If device A registration fails, there is still a chance to register device
B. i3c_master_add_i3c_dev_locked() can reset DAA if a failure occurs while
retrieving device information.
Cc: stable@xxxxxxxxxx
Fixes: 317bacf960a4 ("i3c: master: add enable(disable) hot join in sys entry")
Reviewed-by: Miquel Raynal <miquel.raynal@xxxxxxxxxxx>
Signed-off-by: Frank Li <Frank.Li@xxxxxxx>
Link: https://lore.kernel.org/r/20241002-svc-i3c-hj-v6-6-7e6e1d3569ae@xxxxxxx
Signed-off-by: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/i3c/master/svc-i3c-master.c | 27 +++++++++++++++++++++------
1 file changed, 21 insertions(+), 6 deletions(-)
--- a/drivers/i3c/master/svc-i3c-master.c
+++ b/drivers/i3c/master/svc-i3c-master.c
@@ -1018,12 +1018,27 @@ static int svc_i3c_master_do_daa(struct
goto rpm_out;
}
- /* Register all devices who participated to the core */
- for (i = 0; i < dev_nb; i++) {
- ret = i3c_master_add_i3c_dev_locked(m, addrs[i]);
- if (ret)
- goto rpm_out;
- }
+ /*
+ * Register all devices who participated to the core
+ *
+ * If two devices (A and B) are detected in DAA and address 0xa is assigned to
+ * device A and 0xb to device B, a failure in i3c_master_add_i3c_dev_locked()
+ * for device A (addr: 0xa) could prevent device B (addr: 0xb) from being
+ * registered on the bus. The I3C stack might still consider 0xb a free
+ * address. If a subsequent Hotjoin occurs, 0xb might be assigned to Device A,
+ * causing both devices A and B to use the same address 0xb, violating the I3C
+ * specification.
+ *
+ * The return value for i3c_master_add_i3c_dev_locked() should not be checked
+ * because subsequent steps will scan the entire I3C bus, independent of
+ * whether i3c_master_add_i3c_dev_locked() returns success.
+ *
+ * If device A registration fails, there is still a chance to register device
+ * B. i3c_master_add_i3c_dev_locked() can reset DAA if a failure occurs while
+ * retrieving device information.
+ */
+ for (i = 0; i < dev_nb; i++)
+ i3c_master_add_i3c_dev_locked(m, addrs[i]);
/* Configure IBI auto-rules */
ret = svc_i3c_update_ibirules(master);
