[PATCH] i3c: master: svc: report timeout waiting for STOP idle

[PATCH] i3c: master: svc: report timeout waiting for STOP idle

[Pengpeng Hou]

svc_i3c_master_xfer() emits STOP or force-exit for the final transfer
and then waits for the controller state to become idle, but ignores
readl_poll_timeout(). The function can therefore return success while
the controller is still not idle.

Return the idle-wait error through the existing warning/FIFO cleanup
path so the caller observes the failed transfer without emitting a
second STOP after the final STOP or force-exit has already been sent.

Signed-off-by: Pengpeng Hou <pengpeng@iscas.ac.cn>
---
 drivers/i3c/master/svc-i3c-master.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/i3c/master/svc-i3c-master.c b/drivers/i3c/master/svc-i3c-master.c
index 93805df8a940..93ae6eb1a355 100644
--- a/drivers/i3c/master/svc-i3c-master.c
+++ b/drivers/i3c/master/svc-i3c-master.c
@@ -1488,8 +1488,11 @@ static int svc_i3c_master_xfer(struct svc_i3c_master *master,
 			svc_i3c_master_emit_force_exit(master);
 
 		/* Wait idle if stop is sent. */
-		readl_poll_timeout(master->regs + SVC_I3C_MSTATUS, reg,
-				   SVC_I3C_MSTATUS_STATE_IDLE(reg), 0, 1000);
+		ret = readl_poll_timeout(master->regs + SVC_I3C_MSTATUS, reg,
+					 SVC_I3C_MSTATUS_STATE_IDLE(reg),
+					 0, 1000);
+		if (ret)
+			goto cleanup;
 	}
 
 	return 0;
@@ -1502,6 +1505,7 @@ static int svc_i3c_master_xfer(struct svc_i3c_master *master,
 	else
 		svc_i3c_master_emit_force_exit(master);
 
+cleanup:
 	svc_i3c_master_clear_merrwarn(master);
 	svc_i3c_master_flush_fifo(master);
 
-- 
2.50.1 (Apple Git-155)

Re: [PATCH] i3c: master: svc: report timeout waiting for STOP idle

[Miquel Raynal]

Hello,

On 23/06/2026 at 14:08:21 +08, Pengpeng Hou <pengpeng@iscas.ac.cn> wrote:

> svc_i3c_master_xfer() emits STOP or force-exit for the final transfer
> and then waits for the controller state to become idle, but ignores
> readl_poll_timeout(). The function can therefore return success while
> the controller is still not idle.
>
> Return the idle-wait error through the existing warning/FIFO cleanup
> path so the caller observes the failed transfer without emitting a
> second STOP after the final STOP or force-exit has already been sent.
>
> Signed-off-by: Pengpeng Hou <pengpeng@iscas.ac.cn>

Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>

Thanks,
Miquèl

Re: [PATCH] i3c: master: svc: report timeout waiting for STOP idle

[Frank Li]

On Tue, Jun 23, 2026 at 02:08:21PM +0800, Pengpeng Hou wrote:
>
> svc_i3c_master_xfer() emits STOP or force-exit for the final transfer
> and then waits for the controller state to become idle, but ignores
> readl_poll_timeout(). The function can therefore return success while
> the controller is still not idle.
>
> Return the idle-wait error through the existing warning/FIFO cleanup
> path so the caller observes the failed transfer without emitting a
> second STOP after the final STOP or force-exit has already been sent.
>
> Signed-off-by: Pengpeng Hou <pengpeng@iscas.ac.cn>
> ---

Dose you really met timeout? if yes, what step to reproduce it. Suppose
only few FCLK to emit STOP or force-exit unconditional.

Any way not harmful to add check it.

Reviewed-by: Frank Li <Frank.Li@nxp.com>

>  drivers/i3c/master/svc-i3c-master.c | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/i3c/master/svc-i3c-master.c b/drivers/i3c/master/svc-i3c-master.c
> index 93805df8a940..93ae6eb1a355 100644
> --- a/drivers/i3c/master/svc-i3c-master.c
> +++ b/drivers/i3c/master/svc-i3c-master.c
> @@ -1488,8 +1488,11 @@ static int svc_i3c_master_xfer(struct svc_i3c_master *master,
>                         svc_i3c_master_emit_force_exit(master);
>
>                 /* Wait idle if stop is sent. */
> -               readl_poll_timeout(master->regs + SVC_I3C_MSTATUS, reg,
> -                                  SVC_I3C_MSTATUS_STATE_IDLE(reg), 0, 1000);
> +               ret = readl_poll_timeout(master->regs + SVC_I3C_MSTATUS, reg,
> +                                        SVC_I3C_MSTATUS_STATE_IDLE(reg),
> +                                        0, 1000);
> +               if (ret)
> +                       goto cleanup;
>         }
>
>         return 0;
> @@ -1502,6 +1505,7 @@ static int svc_i3c_master_xfer(struct svc_i3c_master *master,
>         else
>                 svc_i3c_master_emit_force_exit(master);
>
> +cleanup:
>         svc_i3c_master_clear_merrwarn(master);
>         svc_i3c_master_flush_fifo(master);
>
> --
> 2.50.1 (Apple Git-155)
>
>

Re: [PATCH] i3c: master: svc: report timeout waiting for STOP idle

[Alexandre Belloni]

On Tue, 23 Jun 2026 14:08:21 +0800, Pengpeng Hou wrote:
> svc_i3c_master_xfer() emits STOP or force-exit for the final transfer
> and then waits for the controller state to become idle, but ignores
> readl_poll_timeout(). The function can therefore return success while
> the controller is still not idle.
> 
> Return the idle-wait error through the existing warning/FIFO cleanup
> path so the caller observes the failed transfer without emitting a
> second STOP after the final STOP or force-exit has already been sent.
> 
> [...]

Applied, thanks!

[1/1] i3c: master: svc: report timeout waiting for STOP idle
      https://git.kernel.org/i3c/c/90ae03e37e26

Best regards,

-- 
Alexandre Belloni, co-owner and COO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com