/*
 * Handling of a single switch chip, part of a switch fabric
 *
 * Copyright (c) 2017 Vivien Didelot <vivien.didelot@savoirfairelinux.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 */

#include <linux/netdevice.h>
#include <linux/notifier.h>
#include <net/dsa.h>

static int dsa_switch_bridge_join(struct dsa_switch *ds,
				  struct dsa_notifier_bridge_info *info)
{
	if (ds->index == info->sw_index && ds->ops->port_bridge_join)
		return ds->ops->port_bridge_join(ds, info->port, info->br);

	if (ds->index != info->sw_index)
		dev_dbg(ds->dev, "crosschip DSA port %d.%d bridged to %s\n",
			info->sw_index, info->port, netdev_name(info->br));

	return 0;
}

static int dsa_switch_bridge_leave(struct dsa_switch *ds,
				   struct dsa_notifier_bridge_info *info)
{
	if (ds->index == info->sw_index && ds->ops->port_bridge_leave)
		ds->ops->port_bridge_leave(ds, info->port, info->br);

	if (ds->index != info->sw_index)
		dev_dbg(ds->dev, "crosschip DSA port %d.%d unbridged from %s\n",
			info->sw_index, info->port, netdev_name(info->br));

	return 0;
}

static int dsa_switch_event(struct notifier_block *nb,
			    unsigned long event, void *info)
{
	struct dsa_switch *ds = container_of(nb, struct dsa_switch, nb);
	int err;

	switch (event) {
	case DSA_NOTIFIER_BRIDGE_JOIN:
		err = dsa_switch_bridge_join(ds, info);
		break;
	case DSA_NOTIFIER_BRIDGE_LEAVE:
		err = dsa_switch_bridge_leave(ds, info);
		break;
	default:
		err = -EOPNOTSUPP;
		break;
	}

	/* Non-switchdev operations cannot be rolled back. If a DSA driver
	 * returns an error during the chained call, switch chips may be in an
	 * inconsistent state.
	 */
	if (err)
		dev_dbg(ds->dev, "breaking chain for DSA event %lu (%d)\n",
			event, err);

	return notifier_from_errno(err);
}

int dsa_switch_register_notifier(struct dsa_switch *ds)
{
	ds->nb.notifier_call = dsa_switch_event;

	return raw_notifier_chain_register(&ds->dst->nh, &ds->nb);
}

void dsa_switch_unregister_notifier(struct dsa_switch *ds)
{
	int err;

	err = raw_notifier_chain_unregister(&ds->dst->nh, &ds->nb);
	if (err)
		dev_err(ds->dev, "failed to unregister notifier (%d)\n", err);
}
git/log/net/bluetooth'>
<input type='hidden' name='h' value='nds-private-remove'/><input type='hidden' name='id' value='6e978b22efa1db9f6e71b24440b5f1d93e968ee3'/><select name='qt'>
<option value='grep'>log msg</option>
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</select>
<input class='txt' type='search' size='10' name='q' value=''/>
<input type='submit' value='search'/>
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</td></tr></table>
<div class='path'>path: <a href='/cgit.cgi/linux/net-next.git/commit/?h=nds-private-remove&amp;id=6e978b22efa1db9f6e71b24440b5f1d93e968ee3'>root</a>/<a href='/cgit.cgi/linux/net-next.git/commit/net?h=nds-private-remove&amp;id=6e978b22efa1db9f6e71b24440b5f1d93e968ee3'>net</a>/<a href='/cgit.cgi/linux/net-next.git/commit/net/bluetooth?h=nds-private-remove&amp;id=6e978b22efa1db9f6e71b24440b5f1d93e968ee3'>bluetooth</a></div><div class='content'><div class='cgit-panel'><b>diff options</b><form method='get'><input type='hidden' name='h' value='nds-private-remove'/><input type='hidden' name='id' value='6e978b22efa1db9f6e71b24440b5f1d93e968ee3'/><table><tr><td colspan='2'/></tr><tr><td class='label'>context:</td><td class='ctrl'><select name='context' onchange='this.form.submit();'><option value='1'>1</option><option value='2'>2</option><option value='3' selected='selected'>3</option><option value='4'>4</option><option value='5'>5</option><option value='6'>6</option><option value='7'>7</option><option value='8'>8</option><option value='9'>9</option><option value='10'>10</option><option value='15'>15</option><option value='20'>20</option><option value='25'>25</option><option value='30'>30</option><option value='35'>35</option><option value='40'>40</option></select></td></tr><tr><td class='label'>space:</td><td class='ctrl'><select name='ignorews' onchange='this.form.submit();'><option value='0' selected='selected'>include</option><option value='1'>ignore</option></select></td></tr><tr><td class='label'>mode:</td><td class='ctrl'><select name='dt' onchange='this.form.submit();'><option value='0' selected='selected'>unified</option><option value='1'>ssdiff</option><option value='2'>stat only</option></select></td></tr><tr><td/><td class='ctrl'><noscript><input type='submit' value='reload'/></noscript></td></tr></table></form></div><table summary='commit info' class='commit-info'>
<tr><th>author</th><td>Srinivas Pandruvada &lt;srinivas.pandruvada@linux.intel.com&gt;</td><td class='right'>2017-02-03 14:18:39 -0800</td></tr>
<tr><th>committer</th><td>Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;</td><td class='right'>2017-02-04 00:11:08 +0100</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/net/bluetooth?h=nds-private-remove&amp;id=6e978b22efa1db9f6e71b24440b5f1d93e968ee3'>6e978b22efa1db9f6e71b24440b5f1d93e968ee3</a> (<a href='/cgit.cgi/linux/net-next.git/patch/net/bluetooth?id=6e978b22efa1db9f6e71b24440b5f1d93e968ee3'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?h=nds-private-remove&amp;id=6e978b22efa1db9f6e71b24440b5f1d93e968ee3'>c666f7a26b860674848949e39a610222b0723f89</a> /<a href='/cgit.cgi/linux/net-next.git/tree/net/bluetooth?h=nds-private-remove&amp;id=6e978b22efa1db9f6e71b24440b5f1d93e968ee3'>net/bluetooth</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/net/bluetooth?h=nds-private-remove&amp;id=3c223c19aea85d3dda1416c187915f4a30b04b1f'>3c223c19aea85d3dda1416c187915f4a30b04b1f</a> (<a href='/cgit.cgi/linux/net-next.git/diff/net/bluetooth?h=nds-private-remove&amp;id=6e978b22efa1db9f6e71b24440b5f1d93e968ee3&amp;id2=3c223c19aea85d3dda1416c187915f4a30b04b1f'>diff</a>)</td></tr></table>
<div class='commit-subject'>cpufreq: intel_pstate: Disable energy efficiency optimization</div><div class='commit-msg'>Some Kabylake desktop processors may not reach max turbo when running in
HWP mode, even if running under sustained 100% utilization.

This occurs when the HWP.EPP (Energy Performance Preference) is set to
"balance_power" (0x80) -- the default on most systems.

It occurs because the platform BIOS may erroneously enable an
energy-efficiency setting -- MSR_IA32_POWER_CTL BIT-EE, which is not
recommended to be enabled on this SKU.

On the failing systems, this BIOS issue was not discovered when the
desktop motherboard was tested with Windows, because the BIOS also
neglects to provide the ACPI/CPPC table, that Windows requires to enable
HWP, and so Windows runs in legacy P-state mode, where this setting has
no effect.

Linux' intel_pstate driver does not require ACPI/CPPC to enable HWP, and
so it runs in HWP mode, exposing this incorrect BIOS configuration.

There are several ways to address this problem.

First, Linux can also run in legacy P-state mode on this system.
As intel_pstate is how Linux enables HWP, booting with
"intel_pstate=disable"
will run in acpi-cpufreq/ondemand legacy p-state mode.

Or second, the "performance" governor can be used with intel_pstate,
which will modify HWP.EPP to 0.

Or third, starting in 4.10, the
/sys/devices/system/cpu/cpufreq/policy*/energy_performance_preference
attribute in can be updated from "balance_power" to "performance".

Or fourth, apply this patch, which fixes the erroneous setting of
MSR_IA32_POWER_CTL BIT_EE on this model, allowing the default
configuration to function as designed.

Signed-off-by: Srinivas Pandruvada &lt;srinivas.pandruvada@linux.intel.com&gt;
Reviewed-by: Len Brown &lt;len.brown@intel.com&gt;
Cc: 4.6+ &lt;stable@vger.kernel.org&gt; # 4.6+
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?h=nds-private-remove&amp;id=6e978b22efa1db9f6e71b24440b5f1d93e968ee3'>Diffstat</a> (limited to 'net/bluetooth')</div><table summary='diffstat' class='diffstat'>