i3c: renesas: Don't register devices when ENTDAA times out

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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: d028219a9f ("i3c: master: Add basic driver for the Renesas I3C controller")
Signed-off-by: Tommaso Merciai <tommaso.merciai.xr@bp.renesas.com>
Reviewed-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Tested-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com> # on RZ/G3S
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Link: https://patch.msgid.link/20260731070150.2519825-1-tommaso.merciai.xr@bp.renesas.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

...

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Tommaso Merciai 2026-07-31 09:01:46 +02:00 • committed by Alexandre Belloni

parent 7315aad228

commit b6e56fd8c8

1 changed files with 1 additions and 1 deletions

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drivers/i3c/master/renesas-i3c.c

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