Re: [PATCH V1 16/20] accel/amdxdna: Implement AIE4 suspend and resume

["Zhang, Yidong (David)" <yidong.zhang@amd.com>]

On 9/29/2026 9:07 PM, sashiko-bot@kernel.org wrote:
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>
> Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
> - [High] amdxdna: submitter thread hangs forever on failed device resume
> --
>
> commit 3c6d084a73c19b1b3a172be33a5eb12a9d7f8889
> Author: David Zhang <yidong.zhang@amd.com>
>
>      accel/amdxdna: Implement AIE4 suspend and resume
>
>      Implement suspend and resume callbacks for AIE4 Physical Function (PF),
>      Virtual Function (VF), and Classic device types.
>
>> diff --git a/drivers/accel/amdxdna/aie4_pci.c b/drivers/accel/amdxdna/aie4_pci.c
>> index f180983a692dc..6a50c1499ec93 100644
>> --- a/drivers/accel/amdxdna/aie4_pci.c
>> +++ b/drivers/accel/amdxdna/aie4_pci.c
> [ ... ]
>
>> @@ -1096,11 +1096,250 @@ static void aie4_debugfs_init(struct amdxdna_dev *xdna)
> [ ... ]
>
>> +static int aie4_vf_resume(struct amdxdna_dev *xdna)
>> +{
> [ ... ]
>
>> +     ret = aie4_hwctx_resume_all(ndev);
>> +     if (ret) {
>> +             XDNA_ERR(xdna, "hwctx_resume failed %d", ret);
>> +             goto hw_clear;
>> +     }
>> +
>> +     XDNA_DBG(xdna, "vf resume done");
>> +     return 0;
>> +
>> +hw_clear:
>> +     aie4_hwctx_suspend_all(ndev, true);
>> +     aie4_vf_hw_stop(ndev);
>> +pci_disable:
>> +     pci_disable_device(pdev);
> [Severity: High]
> Could this error path leave submitter threads permanently hung in an
> uninterruptible wait?
>
> When aie4_vf_resume() or aie4_classic_resume() fails, they call
> aie4_hwctx_suspend_all(ndev, true) which destroys the context with
> AIE4_HWCTX_ERROR (setting has_reset = true).
>
> However, a submitter thread waiting in wait_till_connected_hsa_not_full() in
> drivers/accel/amdxdna/aie4_ctx.c with wait_through_reset = true explicitly
> ignores has_reset:
>
>      ret = wait_event_freezable(priv->job_list_wq,
>                                 aie4_hwctx_connected(hwctx) ||
>                                 (!wait_through_reset &&
>                                  aie4_hwctx_has_reset(hwctx)));
>
> Since the hardware resume failed, the context will never be recreated and
> connected, causing it to block forever. This holds the srcu read lock and
> prevents device removal (causing a deadlock in synchronize_srcu()).

I will fix the synchronize_srcu() deadlock in context teardown by stopping
the hardware context and waking all waiters before destroying it.
The fix will be in upcoming PATCH V2.

/David

>> +     return ret;
>> +}
> --
> Sashiko AI review · https://sashiko.dev/#/patchset/20260930033233.1727265-1-yidong.zhang@amd.com?part=16