Re: [PATCH] fix: accel/habanalabs: hl_cs_signal_sob_wraparound_handler: missing hw_sob_get when need_reset is true and encaps_sig is false

[WenTao Liang]

> 2026年6月26日 18:44，WenTao Liang <vu...@iscas.ac.cn> 写道：
> 
> When other_sob->need_reset is true and encaps_sig is false,
>  hw_sob_put(other_sob) decrements the kref to 0, but the matching
>  hw_sob_get(other_sob) is skipped because it is inside the encaps_sig
>  block. The function returns other_sob with kref=0, causing a subsequent
>  kref_put to underflow. Fix by adding hw_sob_get(other_sob) in the else
>  branch.
> 
> Cc: sta...@vger.kernel.org
> Fixes: dadf17abb724 ("habanalabs: add support for encapsulated signals 
> reservation")
> Signed-off-by: WenTao Liang <vu...@iscas.ac.cn>
> ---
> drivers/accel/habanalabs/common/command_submission.c | 5 ++---
> 1 file changed, 2 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/accel/habanalabs/common/command_submission.c 
> b/drivers/accel/habanalabs/common/command_submission.c
> index ba4257bda77b..675301dfc0ef 100644
> --- a/drivers/accel/habanalabs/common/command_submission.c
> +++ b/drivers/accel/habanalabs/common/command_submission.c
> @@ -1860,11 +1860,10 @@ int hl_cs_signal_sob_wraparound_handler(struct 
> hl_device *hdev, u32 q_idx,
>               if (other_sob->need_reset)
>                       hw_sob_put(other_sob);
> 
> -             if (encaps_sig) {
> +             if (encaps_sig)
>                       /* set reset indication for the sob */
>                       sob->need_reset = true;
> -                     hw_sob_get(other_sob);
> -             }
> +             hw_sob_get(other_sob);
> 
>               dev_dbg(hdev->dev, "switched to SOB %d, q_idx: %d\n",
>                               prop->curr_sob_offset, q_idx);
> -- 
> 2.39.5 (Apple Git-154)

Please ignore this patch. I will resend a proper version after
learning the kernel submission process.

Apologies for the noise.

Best regards,
WenTao Liang