> -----Original Message----- > From: Kai Heng Feng [mailto:kai.heng.feng@xxxxxxxxxxxxx] > Sent: Thursday, November 23, 2017 9:44 PM > To: Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> > Cc: David Miller <davem@xxxxxxxxxxxxx>; hayeswang@xxxxxxxxxx; linux- > usb@xxxxxxxxxxxxxxx; netdev@xxxxxxxxxxxxxxx; LKML <linux- > kernel@xxxxxxxxxxxxxxx>; Limonciello, Mario <Mario_Limonciello@xxxxxxxx> > Subject: Re: [PATCH] r8152: disable rx checksum offload on Dell TB dock > > > > > On 23 Nov 2017, at 5:24 PM, Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: > > > > On Thu, Nov 23, 2017 at 04:53:41PM +0800, Kai Heng Feng wrote: > >> > >> What I want to do here is to finding this connection: > >> Realtek r8153 <-> SMSC hub (USD ID: 0424:5537) <-> > >> ASMedia XHCI controller (PCI ID: 1b21:1142). > >> > >> Is there a safer way to do this? > > > > Nope! You can't do that at all from within a USB driver, sorry. As you > > really should not care at all :) > > Got it :) > > The r8153 in Dell TB dock has version information, RTL_VER_05. > We can use it to check for workaround, but many working RTL_VER_05 devices > will also be affected. > Do you think it’s an acceptable compromise? > > >> I have a r8153 <-> USB 3.0 dongle which work just fine. I can’t find any > >> information to differentiate them. Hence I want to use the connection to > >> identify if r8153 is on a Dell TB dock. > > > > Are you sure there is nothing different in the version or release number > > of the device? 'lsusb -v' shows the exact same information for both > > devices? > > Yes. I attached `lsusb -v` for r8153 on Dell TB dock, on a RJ45 <-> USB 3.0 dongle, > and on a RJ45 <-> USB Type-C dongle. > > >> Yes. From what I know, ASMedia is working on it, but not sure how long it > >> will take. In the meantime, I’d like to workaround this issue for the users. > > > > Again, it's a host controller bug, it should be fixed there, don't try > > to paper over the real issue in different individual drivers. > > > > I think I've seen various patches on the linux-usb list for this > > controller already, have you tried them? > > Yes. These patches are all in mainline Linux now. > > >> Actually no. > >> I just plugged r8153 dongle into the same hub, surprisingly the issue > >> doesn’t happen in this scenario. > > > > Then something seems to be wrong with the device itself, as that would > > be the same exact electrical/logical path, right? > > I have no idea why externally plugged one doesn’t have this issue. > Maybe it’s related how it’s wired inside the Dell TB dock... > > Kai-Heng This is quite surprising to me too. The externally plugged in r8153 dongle, was it connected over type C port or over type A port? AFAIK Type C port is actually Alpine ridge pass through port. It is not connected to XHCI controller or USB hub. ��.n��������+%������w��{.n�����{���)�� jg��� �����ݢj����G���� ���j:+v���w�m������w�������h�����٥
