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Subject: Re: [PATCH v2] r8152: disable RX aggregation on Dell TB16 dock
From:   Kai Heng Feng <kai.heng.feng@canonical.com>
In-Reply-To: <0835B3720019904CB8F7AA43166CEEB2D2E16D63@RTITMBSV06.realtek.com.tw>
Date:   Thu, 18 Jan 2018 11:38:02 +0800
Cc:     David Miller <davem@davemloft.net>,
        "gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>,
        "linux-usb@vger.kernel.org" <linux-usb@vger.kernel.org>,
        "netdev@vger.kernel.org" <netdev@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "mario.limonciello@dell.com" <mario.limonciello@dell.com>,
        nic_swsd <nic_swsd@realtek.com>
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Message-Id: <58AE3E96-3A52-40C1-9A54-BE2E6D3A3510@canonical.com>
References: <20180116084627.12638-1-kai.heng.feng@canonical.com>
 <20180117.153930.330864749049561139.davem@davemloft.net>
 <0835B3720019904CB8F7AA43166CEEB2D2E16D63@RTITMBSV06.realtek.com.tw>
To:     Hayes Wang <hayeswang@realtek.com>
Sender: linux-kernel-owner@vger.kernel.org
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> On 18 Jan 2018, at 11:04 AM, Hayes Wang <hayeswang@realtek.com> wrote:
> 
> [...]
>>> r8153 on Dell TB15/16 dock corrupts rx packets.
>>> 
>>> This change is suggested by Realtek. They guess that the XHCI
>>> controller doesn't have enough buffer, and their guesswork is correct,
>>> once the RX aggregation gets disabled, the issue is gone.
>>> 
>>> ASMedia is currently working on a real sulotion for this issue.
>>> 
>>> Dell and ODM confirm the bcdDevice and iSerialNumber is unique for TB16.
>>> 
>>> Note that TB15 has different bcdDevice and iSerialNumber, which are
>>> not unique values. If you still have TB15, please contact Dell to
>>> replace it with TB16.
> 
> Excuse me. I don't understand why this patch is for specific USB nic rather than xHCI.
> It seems to make the specific USB nic working and the other ones keeping error.

This patch is transient, once ASMedia find the correct solution, the patch
can be reverted.

This patch only targets the builtin 8153 because externally plugged r8152 or
asix do not suffered from this issue.

Kai-Heng

> 
> 
> Best Regards,
> Hayes
> 
>