From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from faith.sw1v.org ([109.74.200.146]:35810 "EHLO faith.sw1v.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752038AbcHXRBL (ORCPT ); Wed, 24 Aug 2016 13:01:11 -0400 Received: from hindenburg.openmarket.com ([83.166.71.24] helo=[192.168.26.176]) by faith.sw1v.org (envelope-from ) with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) id 1bcbEU-0001MK-QV for linux-pci@vger.kernel.org; Wed, 24 Aug 2016 17:40:54 +0100 To: linux-pci@vger.kernel.org From: Richard van der Hoff Subject: Hotplug not working for USB 3.1 docking station on Dell XPS 13 Message-ID: <57BDCE15.4080201@rvanderhoff.org.uk> Date: Wed, 24 Aug 2016 17:40:53 +0100 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Sender: linux-pci-owner@vger.kernel.org List-ID: Hi, I'm having problems with a Plugable USB-C docking station, with my laptop, a Dell XPS 13 (9350). If the docking station is plugged in at boot, it works correctly; however, when I hotplug it after boot, the USB devices are not detected until I force a rescan of the PCI bus. I have also raised this as a bug at https://bugzilla.kernel.org/show_bug.cgi?id=151261. There are some dmesg traces and lspci logs attached to that bug. The lspci output suggests a chain of three PCI bridges (00:1c.0, 01:00.0, 02:02.0) before a PCI->USB bridge (05:00.0 or 39:00.0). If I boot without the docking station plugged in, 01:00.0 and beyond do not appear, and nor do they appear on hotplug. However, if I hotplug the docking station and then force a rescan with "echo 1 > /sys/bus/pci/devices/0000:00:1c.0/rescan", the PCI bridges and USB devices appear and spring into life. My impression, and feedback from the linux-usb mailing list, is therefore that this is a PCI hotplug problem. There are some ACPI errors in the dmesg at hotplug but they don't really mean much to me. I'd really appreciate any suggestions on how to proceed with this. Thanks Richard van der Hoff