linux-kernel - Re: [PATCH] accel/amdxdna: Fix deadlock between context destroy and job timeout

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Message-ID: <9450655f-233a-804b-465a-d7a7e969ff8b@amd.com>
Date: Thu, 13 Nov 2025 09:24:40 -0800
From: Lizhi Hou <lizhi.hou@....com>
To: "Falkowski, Maciej" <maciej.falkowski@...ux.intel.com>,
	<ogabbay@...nel.org>, <quic_jhugo@...cinc.com>,
	<dri-devel@...ts.freedesktop.org>
CC: <linux-kernel@...r.kernel.org>, <max.zhen@....com>,
	<sonal.santan@....com>, <mario.limonciello@....com>
Subject: Re: [PATCH] accel/amdxdna: Fix deadlock between context destroy and
 job timeout


On 11/13/25 08:45, Falkowski, Maciej wrote:
> Reviewed-by: Maciej Falkowski <maciej.falkowski@...ux.intel.com>
>
> You could add some lockdep assertions for dev_lock to better track its 
> state.

Thanks :)  Added lockdep_assert_held check and applied to drm-misc-next.


Lizhi

>
> Best regards,
> Maciej
>
> On 11/7/2025 7:10 PM, Lizhi Hou wrote:
>> Hardware context destroy function holds dev_lock while waiting for 
>> all jobs
>> to complete. The timeout job also needs to acquire dev_lock, this 
>> leads to
>> a deadlock.
>>
>> Fix the issue by temporarily releasing dev_lock before waiting for all
>> jobs to finish, and reacquiring it afterward.
>>
>> Fixes: 4fd6ca90fc7f ("accel/amdxdna: Refactor hardware context 
>> destroy routine")
>> Signed-off-by: Lizhi Hou <lizhi.hou@....com>
>> ---
>>   drivers/accel/amdxdna/aie2_ctx.c | 6 ++++--
>>   1 file changed, 4 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/accel/amdxdna/aie2_ctx.c 
>> b/drivers/accel/amdxdna/aie2_ctx.c
>> index bdc90fe8a47e..42d876a427c5 100644
>> --- a/drivers/accel/amdxdna/aie2_ctx.c
>> +++ b/drivers/accel/amdxdna/aie2_ctx.c
>> @@ -690,17 +690,19 @@ void aie2_hwctx_fini(struct amdxdna_hwctx *hwctx)
>>       xdna = hwctx->client->xdna;
>>         XDNA_DBG(xdna, "%s sequence number %lld", hwctx->name, 
>> hwctx->priv->seq);
>> -    drm_sched_entity_destroy(&hwctx->priv->entity);
>> -
>>       aie2_hwctx_wait_for_idle(hwctx);
>>         /* Request fw to destroy hwctx and cancel the rest pending 
>> requests */
>>       aie2_release_resource(hwctx);
>>   +    mutex_unlock(&xdna->dev_lock);
>> +    drm_sched_entity_destroy(&hwctx->priv->entity);
>> +
>>       /* Wait for all submitted jobs to be completed or canceled */
>>       wait_event(hwctx->priv->job_free_wq,
>>              atomic64_read(&hwctx->job_submit_cnt) ==
>>              atomic64_read(&hwctx->job_free_cnt));
>> +    mutex_lock(&xdna->dev_lock);
>>         drm_sched_fini(&hwctx->priv->sched);
>>       aie2_ctx_syncobj_destroy(hwctx);