6.6-stable review patch. If anyone has any objections, please let me know.
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From: Frank Li Frank.Li@nxp.com
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@kernel.org Fixes: 317bacf960a4 ("i3c: master: add enable(disable) hot join in sys entry") Reviewed-by: Miquel Raynal miquel.raynal@bootlin.com Signed-off-by: Frank Li Frank.Li@nxp.com Link: https://lore.kernel.org/r/20241002-svc-i3c-hj-v6-6-7e6e1d3569ae@nxp.com Signed-off-by: Alexandre Belloni alexandre.belloni@bootlin.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- 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);