Re: r8169 take too long to complete driver initialization

From: Chris Chiu <chiu@endlessm.com>
To: nic_swsd@realtek.com, netdev@vger.kernel.org,
	Linux Kernel <linux-kernel@vger.kernel.org>,
	Linux Upstreaming Team <linux@endlessm.com>
Subject: Re: r8169 take too long to complete driver initialization
Date: Mon, 29 Jan 2018 18:12:26 +0800	[thread overview]
Message-ID: <CAB4CAwfXF3RSiAMsjOe5RkAT8dh__A3677XuDwxwrarxdrZpZQ@mail.gmail.com> (raw)
In-Reply-To: <CAB4CAwf8zFc8DtzjceATaZbrHJakioPHp7MPb+h7Sa1ySB-_RQ@mail.gmail.com>

On Fri, Jan 5, 2018 at 10:17 AM, Chris Chiu <chiu@endlessm.com> wrote:
> On Wed, Dec 20, 2017 at 4:41 PM, Chris Chiu <chiu@endlessm.com> wrote:
>> Hi,
>>     We've hit a suspend/resume issue on a Acer desktop caused by r8169
>> driver. The dmseg
>> https://gist.github.com/mschiu77/b741849b5070281daaead8dfee312d1a
>> shows it's still in msleep() within a mutex lock.
>>     After looking into the code, it's caused by the
>> rtl8168ep_stop_cmac() which is waiting 100 seconds for
>> rtl_ocp_tx_cond. The following dmesg states that the r8169 driver is
>> loaded.
>>
>> [   20.270526] r8169 Gigabit Ethernet driver 2.3LK-NAPI loaded
>>
>> But it takes > 100 seconds to get the following messages
>>
>> [  140.400223] r8169 0000:02:00.0 (unnamed net_device)
>> (uninitialized): rtl_ocp_tx_cond == 1 (loop: 2000, delay: 50).
>> [  140.413294] r8169 0000:02:00.0 eth0: RTL8168ep/8111ep at
>> 0xffffb16c80db1000, f8:0f:41:ea:74:0d, XID 10200800 IRQ 46
>> [  140.413297] r8169 0000:02:00.0 eth0: jumbo features [frames: 9200
>> bytes, tx checksumming: ko]
>>
>> So any trial to suspend the machine during this period would always
>> get device/resource busy message then abort. Is this  rtl_ocp_tx_cond
>> necessary? Because the ethernet is still working and I don't see any
>> problem. I don't know it should be considered normal or not. Please
>> let me know if any more information required. Thanks
>>
>> Chris
>
> gentle ping,
>
> cheers.

Hi,
    Just found a r8168 driver which seems to be authrized by realtek for cross
comparison. I tried applying the patch to latest 4.15 kernel and the driver done
it's initialization in faily short time. The patch file is here
    https://gist.github.com/mschiu77/fcf406e64a1a437f46cf2be643f1057d.

    In mainline r8169.c, the IBISR0 register need to be polled in the
rtl8168ep_stop_cmac().
In the patch file, there's also the same IBISR0 polling code in
Dash2DisableTx(),
but it's been bypassed since the chipset maches HW_DASH_SUPPORT_TYPE_2.
Per the rtl_chip_info[] in r8168_n.c, CFG_METHOD_23/27/28 are
HW_DASH_SUPPORT_TYPE_2,
and they happens to be the only 3 named RTL8168EP/8111EP in the rtl_chip_info[].

    To find the same matches in r8169.c, RTL_GIGA_MAC_VER_49/50/51
seems share the
same config. Can anyone clarify if the rtl_ocp_tx_cond() really
necessary for 8168EP/8111EP?
Or we can just ignore the condition check for RTL_GIGA_MAC_VER_49/50/51?

Chris