Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S937105AbdCJMcN (ORCPT ); Fri, 10 Mar 2017 07:32:13 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:45201 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934534AbdCJMTe (ORCPT ); Fri, 10 Mar 2017 07:19:34 -0500 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Guenter Roeck" , "Greg Kroah-Hartman" , "Mathias Nyman" Date: Fri, 10 Mar 2017 11:46:22 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 149/370] xhci: free xhci virtual devices with leaf nodes first In-Reply-To: X-SA-Exim-Connect-IP: 82.70.136.246 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2642 Lines: 80 3.16.42-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Mathias Nyman commit ee8665e28e8d90ce69d4abe5a469c14a8707ae0e upstream. the tt_info provided by a HS hub might be in use to by a child device Make sure we free the devices in the correct order. This is needed in special cases such as when xhci controller is reset when resuming from hibernate, and all virt_devices are freed. Also free the virt_devices starting from max slot_id as children more commonly have higher slot_id than parent. Reported-by: Guenter Roeck Tested-by: Guenter Roeck Signed-off-by: Mathias Nyman Signed-off-by: Greg Kroah-Hartman Signed-off-by: Ben Hutchings --- drivers/usb/host/xhci-mem.c | 38 ++++++++++++++++++++++++++++++++++++-- 1 file changed, 36 insertions(+), 2 deletions(-) --- a/drivers/usb/host/xhci-mem.c +++ b/drivers/usb/host/xhci-mem.c @@ -965,6 +965,40 @@ void xhci_free_virt_device(struct xhci_h xhci->devs[slot_id] = NULL; } +/* + * Free a virt_device structure. + * If the virt_device added a tt_info (a hub) and has children pointing to + * that tt_info, then free the child first. Recursive. + * We can't rely on udev at this point to find child-parent relationships. + */ +void xhci_free_virt_devices_depth_first(struct xhci_hcd *xhci, int slot_id) +{ + struct xhci_virt_device *vdev; + struct list_head *tt_list_head; + struct xhci_tt_bw_info *tt_info, *next; + int i; + + vdev = xhci->devs[slot_id]; + if (!vdev) + return; + + tt_list_head = &(xhci->rh_bw[vdev->real_port - 1].tts); + list_for_each_entry_safe(tt_info, next, tt_list_head, tt_list) { + /* is this a hub device that added a tt_info to the tts list */ + if (tt_info->slot_id == slot_id) { + /* are any devices using this tt_info? */ + for (i = 1; i < HCS_MAX_SLOTS(xhci->hcs_params1); i++) { + vdev = xhci->devs[i]; + if (vdev && (vdev->tt_info == tt_info)) + xhci_free_virt_devices_depth_first( + xhci, i); + } + } + } + /* we are now at a leaf device */ + xhci_free_virt_device(xhci, slot_id); +} + int xhci_alloc_virt_device(struct xhci_hcd *xhci, int slot_id, struct usb_device *udev, gfp_t flags) { @@ -1828,8 +1862,8 @@ void xhci_mem_cleanup(struct xhci_hcd *x } } - for (i = 1; i < MAX_HC_SLOTS; ++i) - xhci_free_virt_device(xhci, i); + for (i = HCS_MAX_SLOTS(xhci->hcs_params1); i > 0; i--) + xhci_free_virt_devices_depth_first(xhci, i); if (xhci->segment_pool) dma_pool_destroy(xhci->segment_pool);