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Date:   Fri, 14 Oct 2022 10:56:08 +0300
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Subject: Re: [PATCH] xhci: print warning when HCE was set
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To:     liulongfang <liulongfang@huawei.com>,
        Mathias Nyman <mathias.nyman@linux.intel.com>,
        gregkh@linuxfoundation.org
Cc:     linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
        yisen.zhuang@huawei.com
References: <20220915011134.58400-1-liulongfang@huawei.com>
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 <19ab61d6-c2a2-42be-2bb6-500636868703@huawei.com>
From:   Mathias Nyman <mathias.nyman@intel.com>
In-Reply-To: <19ab61d6-c2a2-42be-2bb6-500636868703@huawei.com>
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On 14.10.2022 6.12, liulongfang wrote:
> On 2022/9/26 15:58, Mathias Nyman wrote:
>> On 24.9.2022 5.35, liulongfang wrote:
>>> On 2022/9/22 21:01, Mathias Nyman Wrote:
>>>> Hi
>>>>
>>>> On 15.9.2022 4.11, Longfang Liu wrote:
>>>>> When HCE(Host Controller Error) is set, it means that the xhci hardware
>>>>> controller has an error at this time, but the current xhci driver
>>>>> software does not log this event.
>>>>>
>>>>> By adding an HCE event detection in the xhci interrupt processing
>>>>> interface, a warning log is output to the system, which is convenient
>>>>> for system device status tracking.
>>>>>
>>>>
>>>> xHC should cease all activity when it sets HCE, and is probably not
>>>> generating interrupts anymore.
>>>>
>>>> Would probably be more useful to check for HCE at timeouts than in the
>>>> interrupt handler.
>>>>
>>>
>>> Which function of the driver code is this timeout in?
>>
>> xhci_handle_command_timeout() will usually trigger at some point,
>>
> 
> Because this HCE error is reported in the form of an interrupt signal, it is more
> concise to put it in xhci_irq() than in xhci_handle_command_timeout().
> 

Patch was added to queue after you reported your xHC hardware triggers interrupts when HCE is set.
I'll send it forward after 6.1-rc1

xHCI specification still indicate HCE might not trigger interrupts:
  
Section 4.24.1 -Internal Errors
...
"Software should implement an algorithm for checking the HCE flag if the xHC is
not responding."

Thanks
-Mathias