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Subject: Re: [PATCH 1/1] usb: xhci: handle endpoint error caused by TRB error
To: Mathias Nyman <mathias.nyman@linux.intel.com>
References: <1478826181-15337-1-git-send-email-baolu.lu@linux.intel.com>
Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org
From: Lu Baolu <baolu.lu@linux.intel.com>
Message-ID: <58252545.5000006@linux.intel.com>
Date: Fri, 11 Nov 2016 09:56:21 +0800
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Hi,

On 11/11/2016 09:03 AM, Lu Baolu wrote:
> When xHCI host sees a malformed TRB in a transfer ring,
> it will generate a transfer event with the completion
> code set to COMP_TRB_ERR (5), and sets the endpoint
> state in output endpoint context to EP_STATE_ERROR.
> The endpoint enters ERROR state as the result.
>
> XHCI specification requires that Set TR Dequeue Pointer
> Command shall be used to transition the endpoint from
> Error to Stopped state. Current xHCI driver doesn't
> clear this endpoint error, hence the successive URB
> enqueue requests will result in error messages of
> "WARN waiting for error on ep to be cleared". And the
> corresponding USB device stays in unresponsive state.
>
> This patch enhances xHCI driver on this by printing out
> the malformed TRB and clearing the endpoint Error state.
>
> Tested-by: Wang Wendy <wendy.wang@inte.com>
                                                    ^^^^^
                                                    intel.com

I will correct it with a v2.

Best regards,
Lu Baolu