From: Alan Stern <stern@rowland.harvard.edu>
To: Kai-Heng Feng <kai.heng.feng@canonical.com>
Cc: Mathias Nyman <mathias.nyman@intel.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
AceLan Kao <acelan.kao@canonical.com>,
USB list <linux-usb@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v2 3/3] USB: Disable LPM on WD19's Realtek Hub
Date: Fri, 10 Jan 2020 11:36:43 -0500 (EST) [thread overview]
Message-ID: <Pine.LNX.4.44L0.2001101135450.1467-100000@iolanthe.rowland.org> (raw)
In-Reply-To: <CAAd53p56QynOLJPi3kKiQB1iScrDxj3X1FiycuVF7tP75yPD8A@mail.gmail.com>
On Fri, 10 Jan 2020, Kai-Heng Feng wrote:
> On Fri, Jan 10, 2020 at 11:40 PM Alan Stern <stern@rowland.harvard.edu> wrote:
> >
> > On Fri, 10 Jan 2020, Kai-Heng Feng wrote:
> >
> > > Realtek Hub (0bda:0x0487) used in Dell Dock WD19 sometimes drops off the
> > > bus when bringing underlying ports from U3 to U0.
> > >
> > > Disabling LPM on the hub during setting link state is not enough, so
> > > let's disable LPM completely for this hub.
> > >
> > > Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
> > > ---
> > > drivers/usb/core/quirks.c | 3 +++
> > > 1 file changed, 3 insertions(+)
> > >
> > > diff --git a/drivers/usb/core/quirks.c b/drivers/usb/core/quirks.c
> > > index 6b6413073584..2fb7c1602280 100644
> > > --- a/drivers/usb/core/quirks.c
> > > +++ b/drivers/usb/core/quirks.c
> > > @@ -371,6 +371,9 @@ static const struct usb_device_id usb_quirk_list[] = {
> > > { USB_DEVICE(0x0b05, 0x17e0), .driver_info =
> > > USB_QUIRK_IGNORE_REMOTE_WAKEUP },
> > >
> > > + /* Realtek hub in Dell WD19 (Type-C) */
> > > + { USB_DEVICE(0x0bda, 0x0487), .driver_info = USB_QUIRK_NO_LPM },
> > > +
> > > /* Action Semiconductor flash disk */
> > > { USB_DEVICE(0x10d6, 0x2200), .driver_info =
> > > USB_QUIRK_STRING_FETCH_255 },
> > >
> >
> > This is a very partial patch. There were four hunks in the original
> > version but there's only one hunk in V2.
>
> Because the original approach is insufficient, it significantly
> reduced the fail rate but the issue is still there.
> USB_QUIRK_NO_LPM is used instead so no other parts are needed.
Oh, all right. This change looks okay to me. Has AceLan Kao tested
it?
Alan Stern
next prev parent reply other threads:[~2020-01-10 16:36 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-03 8:40 [PATCH 1/3] xhci: Ensure link state is U3 after setting USB_SS_PORT_LS_U3 Kai-Heng Feng
2020-01-03 8:40 ` [PATCH 2/3] xhci: Wait until link state trainsits to U0 after setting USB_SS_PORT_LS_U0 Kai-Heng Feng
2020-01-10 15:29 ` Mathias Nyman
2020-01-13 9:18 ` Kai-Heng Feng
2020-01-14 14:48 ` Mathias Nyman
2020-01-03 8:40 ` [PATCH 3/3] USB: Disable LPM on WD19's Realtek Hub during setting its ports to U0 Kai-Heng Feng
2020-01-03 15:21 ` Alan Stern
2020-01-03 16:25 ` Kai-Heng Feng
2020-01-03 16:54 ` Alan Stern
2020-01-04 6:41 ` Kai-Heng Feng
2020-01-04 16:20 ` Alan Stern
2020-01-06 6:19 ` Kai-Heng Feng
2020-01-06 15:08 ` Alan Stern
2020-01-10 7:35 ` Kai-Heng Feng
2020-01-10 8:02 ` [PATCH v2 3/3] USB: Disable LPM on WD19's Realtek Hub Kai-Heng Feng
2020-01-10 15:40 ` Alan Stern
2020-01-10 15:51 ` Kai-Heng Feng
2020-01-10 16:36 ` Alan Stern [this message]
2020-01-10 16:46 ` Kai-Heng Feng
2020-01-11 19:23 ` Greg KH
2020-01-13 9:06 ` Kai-Heng Feng
2020-01-10 9:34 ` [PATCH 1/3] xhci: Ensure link state is U3 after setting USB_SS_PORT_LS_U3 Mathias Nyman
2020-01-13 9:10 ` Kai-Heng Feng
2020-01-14 15:07 ` Mathias Nyman
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