Revision 750a7eee7395492960a7aeb3a3a1aa74158ec326 authored by Paul Mundt on 11 November 2011, 06:41:50 UTC, committed by Paul Mundt on 11 November 2011, 06:41:50 UTC
The runtime PM platform support stub in use by ARM-based SH/R-Mobile platforms contains nothing that's specifically ARM-related and instead of wholly generic to anything using the clock framework. The recent runtime PM changes interact rather badly with the lazy disabling of clocks late in the boot process through the clock framework, leading to situations where the runtime suspend/resume paths are entered without a clock being actively driven due to having been lazily gated off. In order to correct this we can trivially tie in the aforementioned stub as a general fallback for all SH platforms that don't presently have their own runtime PM implementations (the corner case being SH-based SH-Mobile platforms, which have their own stub through the hwblk API -- which in turn has bitrotted and will be subsequently adapted to use the same stub as everyone else), regardless of whether the platforms choose to define power domains of their own or not. This fixes up regressions for clock framework users who also build in runtime PM support without any specific power domains of their own, which was previously causing the serial console to be lost when warring with lazy clock disabling. Signed-off-by: Paul Mundt <lethal@linux-sh.org>
1 parent 5e442a4
llist.c
/*
* Lock-less NULL terminated single linked list
*
* The basic atomic operation of this list is cmpxchg on long. On
* architectures that don't have NMI-safe cmpxchg implementation, the
* list can NOT be used in NMI handlers. So code that uses the list in
* an NMI handler should depend on CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG.
*
* Copyright 2010,2011 Intel Corp.
* Author: Huang Ying <ying.huang@intel.com>
*
* 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, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/llist.h>
#include <asm/system.h>
/**
* llist_add_batch - add several linked entries in batch
* @new_first: first entry in batch to be added
* @new_last: last entry in batch to be added
* @head: the head for your lock-less list
*
* Return whether list is empty before adding.
*/
bool llist_add_batch(struct llist_node *new_first, struct llist_node *new_last,
struct llist_head *head)
{
struct llist_node *entry, *old_entry;
entry = head->first;
for (;;) {
old_entry = entry;
new_last->next = entry;
entry = cmpxchg(&head->first, old_entry, new_first);
if (entry == old_entry)
break;
}
return old_entry == NULL;
}
EXPORT_SYMBOL_GPL(llist_add_batch);
/**
* llist_del_first - delete the first entry of lock-less list
* @head: the head for your lock-less list
*
* If list is empty, return NULL, otherwise, return the first entry
* deleted, this is the newest added one.
*
* Only one llist_del_first user can be used simultaneously with
* multiple llist_add users without lock. Because otherwise
* llist_del_first, llist_add, llist_add (or llist_del_all, llist_add,
* llist_add) sequence in another user may change @head->first->next,
* but keep @head->first. If multiple consumers are needed, please
* use llist_del_all or use lock between consumers.
*/
struct llist_node *llist_del_first(struct llist_head *head)
{
struct llist_node *entry, *old_entry, *next;
entry = head->first;
for (;;) {
if (entry == NULL)
return NULL;
old_entry = entry;
next = entry->next;
entry = cmpxchg(&head->first, old_entry, next);
if (entry == old_entry)
break;
}
return entry;
}
EXPORT_SYMBOL_GPL(llist_del_first);
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