Revision 197234520bd83aba2199add57a9d2678ee7f9781 authored by Paul Walmsley on 26 January 2012, 02:50:56 UTC, committed by Greg Kroah-Hartman on 09 February 2012, 18:48:36 UTC
The receive FIFO wakeup latency estimate in the omap-serial driver is three orders of magnitude too small. This effectively prevents the MPU from going to a low-power state when CONFIG_CPU_IDLE=y. This is a major power management regression and masks some other FIFO-related bugs in the driver. Fix by correcting the most egregious problem in the RX wakeup latency estimate. There are several other flaws in the estimator; these will be fixed by a separate patch series intended for 3.4. The difference in low-power states with this patch can be observed via debugfs in pm_debug/count. This estimate does not have any effect when CONFIG_CPU_IDLE=n. Signed-off-by: Paul Walmsley <paul@pwsan.com> Cc: Tomi Valkeinen <tomi.valkeinen@ti.com> Cc: Alan Cox <alan@linux.intel.com> Acked-by: Govindraj.R <govindraj.raja@ti.com> Reviewed-by: Kevin Hilman <khilman@ti.com> Tested-by: Kevin Hilman <khilman@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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mq_sysctl.c
/*
* Copyright (C) 2007 IBM Corporation
*
* Author: Cedric Le Goater <clg@fr.ibm.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, version 2 of the
* License.
*/
#include <linux/nsproxy.h>
#include <linux/ipc_namespace.h>
#include <linux/sysctl.h>
/*
* Define the ranges various user-specified maximum values can
* be set to.
*/
#define MIN_MSGMAX 1 /* min value for msg_max */
#define MAX_MSGMAX HARD_MSGMAX /* max value for msg_max */
#define MIN_MSGSIZEMAX 128 /* min value for msgsize_max */
#define MAX_MSGSIZEMAX (8192*128) /* max value for msgsize_max */
#ifdef CONFIG_PROC_SYSCTL
static void *get_mq(ctl_table *table)
{
char *which = table->data;
struct ipc_namespace *ipc_ns = current->nsproxy->ipc_ns;
which = (which - (char *)&init_ipc_ns) + (char *)ipc_ns;
return which;
}
static int proc_mq_dointvec(ctl_table *table, int write,
void __user *buffer, size_t *lenp, loff_t *ppos)
{
struct ctl_table mq_table;
memcpy(&mq_table, table, sizeof(mq_table));
mq_table.data = get_mq(table);
return proc_dointvec(&mq_table, write, buffer, lenp, ppos);
}
static int proc_mq_dointvec_minmax(ctl_table *table, int write,
void __user *buffer, size_t *lenp, loff_t *ppos)
{
struct ctl_table mq_table;
memcpy(&mq_table, table, sizeof(mq_table));
mq_table.data = get_mq(table);
return proc_dointvec_minmax(&mq_table, write, buffer,
lenp, ppos);
}
#else
#define proc_mq_dointvec NULL
#define proc_mq_dointvec_minmax NULL
#endif
static int msg_max_limit_min = MIN_MSGMAX;
static int msg_max_limit_max = MAX_MSGMAX;
static int msg_maxsize_limit_min = MIN_MSGSIZEMAX;
static int msg_maxsize_limit_max = MAX_MSGSIZEMAX;
static ctl_table mq_sysctls[] = {
{
.procname = "queues_max",
.data = &init_ipc_ns.mq_queues_max,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_mq_dointvec,
},
{
.procname = "msg_max",
.data = &init_ipc_ns.mq_msg_max,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_mq_dointvec_minmax,
.extra1 = &msg_max_limit_min,
.extra2 = &msg_max_limit_max,
},
{
.procname = "msgsize_max",
.data = &init_ipc_ns.mq_msgsize_max,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_mq_dointvec_minmax,
.extra1 = &msg_maxsize_limit_min,
.extra2 = &msg_maxsize_limit_max,
},
{}
};
static ctl_table mq_sysctl_dir[] = {
{
.procname = "mqueue",
.mode = 0555,
.child = mq_sysctls,
},
{}
};
static ctl_table mq_sysctl_root[] = {
{
.procname = "fs",
.mode = 0555,
.child = mq_sysctl_dir,
},
{}
};
struct ctl_table_header *mq_register_sysctl_table(void)
{
return register_sysctl_table(mq_sysctl_root);
}
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