From b6e56fd8c8a8ac7992868a28702192372ab04015 Mon Sep 17 00:00:00 2001 From: Tommaso Merciai Date: Fri, 31 Jul 2026 09:01:46 +0200 Subject: [PATCH] i3c: renesas: Don't register devices when ENTDAA times out renesas_i3c_daa() derives the number of newly assigned dynamic addresses from cmd->rx_count, which the response ISR sets to the number of address slots ENTDAA left unassigned. It starts out as zero, which already means "every address was assigned", so a timed out transfer leaves that value in place and it gets used as a result. On a bus with no target connected the ENTDAA times out and the driver registers RENESAS_I3C_MAX_DEVS devices that are not there, each costing the core two seconds on a GETPID that can only time out: i3c i3c-0: Failed to add I3C device at address 9, error -110 ... i3c i3c-0: Failed to add I3C device at address 16, error -110 Start from maxdevs instead: no address is assigned before ENTDAA runs, and the existing rx_count >= maxdevs check then reports an empty bus. Fixes: d028219a9f14 ("i3c: master: Add basic driver for the Renesas I3C controller") Signed-off-by: Tommaso Merciai Reviewed-by: Claudiu Beznea Tested-by: Claudiu Beznea # on RZ/G3S Reviewed-by: Frank Li Link: https://patch.msgid.link/20260731070150.2519825-1-tommaso.merciai.xr@bp.renesas.com Signed-off-by: Alexandre Belloni --- drivers/i3c/master/renesas-i3c.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/i3c/master/renesas-i3c.c b/drivers/i3c/master/renesas-i3c.c index ff1a243a802e..28c0927a0179 100644 --- a/drivers/i3c/master/renesas-i3c.c +++ b/drivers/i3c/master/renesas-i3c.c @@ -684,7 +684,7 @@ static int renesas_i3c_daa(struct i3c_master_controller *m) init_completion(&xfer->comp); cmd = xfer->cmds; - cmd->rx_count = 0; + cmd->rx_count = i3c->maxdevs; PM_RUNTIME_ACQUIRE_IF_ENABLED_AUTOSUSPEND(i3c->dev, pm); ret = PM_RUNTIME_ACQUIRE_ERR(&pm);