/**************************************************************************
 *
 * Copyright 2006 Tungsten Graphics, Inc., Bismack, ND. USA.
 * All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sub license, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice (including the
 * next paragraph) shall be included in all copies or substantial portions
 * of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
 * USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 *
 **************************************************************************/
/*
 * Simple open hash tab implementation.
 *
 * Authors:
 * Thomas Hellström <thomas-at-tungstengraphics-dot-com>
 */

#ifndef DRM_HASHTAB_H
#define DRM_HASHTAB_H

#include <linux/list.h>

#define drm_hash_entry(_ptr, _type, _member) container_of(_ptr, _type, _member)

struct drm_hash_item {
	struct hlist_node head;
	unsigned long key;
};

struct drm_open_hash {
	struct hlist_head *table;
	u8 order;
};

extern int drm_ht_create(struct drm_open_hash *ht, unsigned int order);
extern int drm_ht_insert_item(struct drm_open_hash *ht, struct drm_hash_item *item);
extern int drm_ht_just_insert_please(struct drm_open_hash *ht, struct drm_hash_item *item,
				     unsigned long seed, int bits, int shift,
				     unsigned long add);
extern int drm_ht_find_item(struct drm_open_hash *ht, unsigned long key, struct drm_hash_item **item);

extern void drm_ht_verbose_list(struct drm_open_hash *ht, unsigned long key);
extern int drm_ht_remove_key(struct drm_open_hash *ht, unsigned long key);
extern int drm_ht_remove_item(struct drm_open_hash *ht, struct drm_hash_item *item);
extern void drm_ht_remove(struct drm_open_hash *ht);

/*
 * RCU-safe interface
 *
 * The user of this API needs to make sure that two or more instances of the
 * hash table manipulation functions are never run simultaneously.
 * The lookup function drm_ht_find_item_rcu may, however, run simultaneously
 * with any of the manipulation functions as long as it's called from within
 * an RCU read-locked section.
 */
#define drm_ht_insert_item_rcu drm_ht_insert_item
#define drm_ht_just_insert_please_rcu drm_ht_just_insert_please
#define drm_ht_remove_key_rcu drm_ht_remove_key
#define drm_ht_remove_item_rcu drm_ht_remove_item
#define drm_ht_find_item_rcu drm_ht_find_item

#endif
cumentation</a></div><div class='content'><div class='cgit-panel'><b>diff options</b><form method='get'><input type='hidden' name='id' value='ae4a3e028bb8b59e7cfeb0cc9ef03d885182ce8b'/><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>Tony Lindgren &lt;tony@atomide.com&gt;</td><td class='right'>2017-01-19 08:49:07 -0800</td></tr>
<tr><th>committer</th><td>Vinod Koul &lt;vinod.koul@intel.com&gt;</td><td class='right'>2017-01-25 11:29:11 +0530</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/tools/perf/Documentation?id=ae4a3e028bb8b59e7cfeb0cc9ef03d885182ce8b'>ae4a3e028bb8b59e7cfeb0cc9ef03d885182ce8b</a> (<a href='/cgit.cgi/linux/net-next.git/patch/tools/perf/Documentation?id=ae4a3e028bb8b59e7cfeb0cc9ef03d885182ce8b'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?id=ae4a3e028bb8b59e7cfeb0cc9ef03d885182ce8b'>139fc7e29f97d6bb6c4dca2a97be2dc3f824bd51</a> /<a href='/cgit.cgi/linux/net-next.git/tree/tools/perf/Documentation?id=ae4a3e028bb8b59e7cfeb0cc9ef03d885182ce8b'>tools/perf/Documentation</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/tools/perf/Documentation?id=49def1853334396f948dcb4cedb9347abb318df5'>49def1853334396f948dcb4cedb9347abb318df5</a> (<a href='/cgit.cgi/linux/net-next.git/diff/tools/perf/Documentation?id=ae4a3e028bb8b59e7cfeb0cc9ef03d885182ce8b&amp;id2=49def1853334396f948dcb4cedb9347abb318df5'>diff</a>)</td></tr></table>
<div class='commit-subject'>dmaengine: cppi41: Fix runtime PM timeouts with USB mass storage</div><div class='commit-msg'>Commit fdea2d09b997 ("dmaengine: cppi41: Add basic PM runtime support")
added runtime PM support for cppi41, but had corner case issues. Some of
the issues were fixed with commit 098de42ad670 ("dmaengine: cppi41: Fix
unpaired pm runtime when only a USB hub is connected"). That fix however
caused a new regression where we can get error -115 messages with USB on
BeagleBone when connecting a USB mass storage device to a hub.

This is because when connecting a USB mass storage device to a hub, the
initial DMA transfers can take over 200ms to complete and cppi41
autosuspend delay times out.

To fix the issue, we want to implement refcounting for chan_busy array
that contains the active dma transfers. Increasing the autosuspend delay
won't help as that the delay could be potentially seconds, and it's best
to let the USB subsystem to deal with the timeouts on errors.

The earlier attempt for runtime PM was buggy as the pm_runtime_get/put()
calls could get unpaired easily as they did not follow the state of
the chan_busy array as described in commit 098de42ad670 ("dmaengine:
cppi41: Fix unpaired pm runtime when only a USB hub is connected".

Let's fix the issue by adding pm_runtime_get() to where a new transfer
is added to the chan_busy array, and calls to pm_runtime_put() where
chan_busy array entry is cleared. This prevents any autosuspend timeouts
from happening while dma transfers are active.

Fixes: 098de42ad670 ("dmaengine: cppi41: Fix unpaired pm runtime when
only a USB hub is connected")
Fixes: fdea2d09b997 ("dmaengine: cppi41: Add basic PM runtime support")
Cc: Andy Shevchenko &lt;andy.shevchenko@gmail.com&gt;
Cc: Bin Liu &lt;b-liu@ti.com&gt;
Cc: Grygorii Strashko &lt;grygorii.strashko@ti.com&gt;
Cc: Kevin Hilman &lt;khilman@baylibre.com&gt;
Cc: Patrick Titiano &lt;ptitiano@baylibre.com&gt;
Cc: Sergei Shtylyov &lt;sergei.shtylyov@cogentembedded.com&gt;
Signed-off-by: Tony Lindgren &lt;tony@atomide.com&gt;
Tested-by: Bin Liu &lt;b-liu@ti.com&gt;
Signed-off-by: Vinod Koul &lt;vinod.koul@intel.com&gt;
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?id=ae4a3e028bb8b59e7cfeb0cc9ef03d885182ce8b'>Diffstat</a> (limited to 'tools/perf/Documentation')</div><table summary='diffstat' class='diffstat'>