/* * UWB radio (channel) management. * * Copyright (C) 2008 Cambridge Silicon Radio Ltd. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License version * 2 as published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see . */ #include #include #include #include "uwb-internal.h" static int uwb_radio_select_channel(struct uwb_rc *rc) { /* * Default to channel 9 (BG1, TFC1) unless the user has * selected a specific channel or there are no active PALs. */ if (rc->active_pals == 0) return -1; if (rc->beaconing_forced) return rc->beaconing_forced; return 9; } /* * Notify all active PALs that the channel has changed. */ static void uwb_radio_channel_changed(struct uwb_rc *rc, int channel) { struct uwb_pal *pal; list_for_each_entry(pal, &rc->pals, node) { if (pal->channel && channel != pal->channel) { pal->channel = channel; if (pal->channel_changed) pal->channel_changed(pal, pal->channel); } } } /* * Change to a new channel and notify any active PALs of the new * channel. * * When stopping the radio, PALs need to be notified first so they can * terminate any active reservations. */ static int uwb_radio_change_channel(struct uwb_rc *rc, int channel) { int ret = 0; struct device *dev = &rc->uwb_dev.dev; dev_dbg(dev, "%s: channel = %d, rc->beaconing = %d\n", __func__, channel, rc->beaconing); if (channel == -1) uwb_radio_channel_changed(rc, channel); if (channel != rc->beaconing) { if (rc->beaconing != -1 && channel != -1) { /* * FIXME: should signal the channel change * with a Channel Change IE. */ ret = uwb_radio_change_channel(rc, -1); if (ret < 0) return ret; } ret = uwb_rc_beacon(rc, channel, 0); } if (channel != -1) uwb_radio_channel_changed(rc, rc->beaconing); return ret; } /** * uwb_radio_start - request that the radio be started * @pal: the PAL making the request. * * If the radio is not already active, a suitable channel is selected * and beacons are started. */ int uwb_radio_start(struct uwb_pal *pal) { struct uwb_rc *rc = pal->rc; int ret = 0; mutex_lock(&rc->uwb_dev.mutex); if (!pal->channel) { pal->channel = -1; rc->active_pals++; ret = uwb_radio_change_channel(rc, uwb_radio_select_channel(rc)); } mutex_unlock(&rc->uwb_dev.mutex); return ret; } EXPORT_SYMBOL_GPL(uwb_radio_start); /** * uwb_radio_stop - request that the radio be stopped. * @pal: the PAL making the request. * * Stops the radio if no other PAL is making use of it. */ void uwb_radio_stop(struct uwb_pal *pal) { struct uwb_rc *rc = pal->rc; mutex_lock(&rc->uwb_dev.mutex); if (pal->channel) { rc->active_pals--; uwb_radio_change_channel(rc, uwb_radio_select_channel(rc)); pal->channel = 0; } mutex_unlock(&rc->uwb_dev.mutex); } EXPORT_SYMBOL_GPL(uwb_radio_stop); /* * uwb_radio_force_channel - force a specific channel to be used * @rc: the radio controller. * @channel: the channel to use; -1 to force the radio to stop; 0 to * use the default channel selection algorithm. */ int uwb_radio_force_channel(struct uwb_rc *rc, int channel) { int ret = 0; mutex_lock(&rc->uwb_dev.mutex); rc->beaconing_forced = channel; ret = uwb_radio_change_channel(rc, uwb_radio_select_channel(rc)); mutex_unlock(&rc->uwb_dev.mutex); return ret; } /* * uwb_radio_setup - setup the radio manager * @rc: the radio controller. * * The radio controller is reset to ensure it's in a known state * before it's used. */ int uwb_radio_setup(struct uwb_rc *rc) { return uwb_rc_reset(rc); } /* * uwb_radio_reset_state - reset any radio manager state * @rc: the radio controller. * * All internal radio manager state is reset to values corresponding * to a reset radio controller. */ void uwb_radio_reset_state(struct uwb_rc *rc) { struct uwb_pal *pal; mutex_lock(&rc->uwb_dev.mutex); list_for_each_entry(pal, &rc->pals, node) { if (pal->channel) { pal->channel = -1; if (pal->channel_changed) pal->channel_changed(pal, -1); } } rc->beaconing = -1; rc->scanning = -1; mutex_unlock(&rc->uwb_dev.mutex); } /* * uwb_radio_shutdown - shutdown the radio manager * @rc: the radio controller. * * The radio controller is reset. */ void uwb_radio_shutdown(struct uwb_rc *rc) { uwb_radio_reset_state(rc); uwb_rc_reset(rc); } right'>2017-01-27 15:00:45 -0600 commit030305d69fc6963c16003f50d7e8d74b02d0a143 (patch) tree363a4e34d199178769b7e7eeb26ea2620a55847b /include/dt-bindings/pwm parent4d191b1b63c209e37bf27938ef365244d3c41084 (diff)
PCI/ASPM: Handle PCI-to-PCIe bridges as roots of PCIe hierarchies
In a struct pcie_link_state, link->root points to the pcie_link_state of the root of the PCIe hierarchy. For the topmost link, this points to itself (link->root = link). For others, we copy the pointer from the parent (link->root = link->parent->root). Previously we recognized that Root Ports originated PCIe hierarchies, but we treated PCI/PCI-X to PCIe Bridges as being in the middle of the hierarchy, and when we tried to copy the pointer from link->parent->root, there was no parent, and we dereferenced a NULL pointer: BUG: unable to handle kernel NULL pointer dereference at 0000000000000090 IP: [<ffffffff9e424350>] pcie_aspm_init_link_state+0x170/0x820 Recognize that PCI/PCI-X to PCIe Bridges originate PCIe hierarchies just like Root Ports do, so link->root for these devices should also point to itself. Fixes: 51ebfc92b72b ("PCI: Enumerate switches below PCI-to-PCIe bridges") Link: https://bugzilla.kernel.org/show_bug.cgi?id=193411 Link: https://bugzilla.opensuse.org/show_bug.cgi?id=1022181 Tested-by: lists@ssl-mail.com Tested-by: Jayachandran C. <jnair@caviumnetworks.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> CC: stable@vger.kernel.org # v4.2+
Diffstat (limited to 'include/dt-bindings/pwm')