Revision c1230df7e19e0f27655c0eb9d966c7e03be7cc50 authored by Paulo Zanoni on 03 May 2012, 01:55:43 UTC, committed by Daniel Vetter on 03 May 2012, 13:55:38 UTC
While testing with the intel_infoframes tool on gen4, I see that when video DIP is disabled, what we write to the DATA memory is not exactly what we read back later. This regression has been introduce in commit 64a8fc0145a1d0fdc25fc9367c2e6c621955fb3b Author: Jesse Barnes <jbarnes@virtuousgeek.org> Date: Thu Sep 22 11:16:00 2011 +0530 drm/i915: fix ILK+ infoframe support That commit was setting VIDEO_DIP_CTL to 0 when initializing, which caused the problem. Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=43947 Cc: stable@kernel.org Tested-by: Yang Guang <guang.a.yang@intel.com> Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com> Reviewed-by: Eugeni Dodonov <eugeni.dodonov@intel.com> [danvet: Pimped commit message by using the usual commit citation layout.] Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
1 parent 6200497
percpu_counter.c
/*
* Fast batching percpu counters.
*/
#include <linux/percpu_counter.h>
#include <linux/notifier.h>
#include <linux/mutex.h>
#include <linux/init.h>
#include <linux/cpu.h>
#include <linux/module.h>
#include <linux/debugobjects.h>
#ifdef CONFIG_HOTPLUG_CPU
static LIST_HEAD(percpu_counters);
static DEFINE_MUTEX(percpu_counters_lock);
#endif
#ifdef CONFIG_DEBUG_OBJECTS_PERCPU_COUNTER
static struct debug_obj_descr percpu_counter_debug_descr;
static int percpu_counter_fixup_free(void *addr, enum debug_obj_state state)
{
struct percpu_counter *fbc = addr;
switch (state) {
case ODEBUG_STATE_ACTIVE:
percpu_counter_destroy(fbc);
debug_object_free(fbc, &percpu_counter_debug_descr);
return 1;
default:
return 0;
}
}
static struct debug_obj_descr percpu_counter_debug_descr = {
.name = "percpu_counter",
.fixup_free = percpu_counter_fixup_free,
};
static inline void debug_percpu_counter_activate(struct percpu_counter *fbc)
{
debug_object_init(fbc, &percpu_counter_debug_descr);
debug_object_activate(fbc, &percpu_counter_debug_descr);
}
static inline void debug_percpu_counter_deactivate(struct percpu_counter *fbc)
{
debug_object_deactivate(fbc, &percpu_counter_debug_descr);
debug_object_free(fbc, &percpu_counter_debug_descr);
}
#else /* CONFIG_DEBUG_OBJECTS_PERCPU_COUNTER */
static inline void debug_percpu_counter_activate(struct percpu_counter *fbc)
{ }
static inline void debug_percpu_counter_deactivate(struct percpu_counter *fbc)
{ }
#endif /* CONFIG_DEBUG_OBJECTS_PERCPU_COUNTER */
void percpu_counter_set(struct percpu_counter *fbc, s64 amount)
{
int cpu;
raw_spin_lock(&fbc->lock);
for_each_possible_cpu(cpu) {
s32 *pcount = per_cpu_ptr(fbc->counters, cpu);
*pcount = 0;
}
fbc->count = amount;
raw_spin_unlock(&fbc->lock);
}
EXPORT_SYMBOL(percpu_counter_set);
void __percpu_counter_add(struct percpu_counter *fbc, s64 amount, s32 batch)
{
s64 count;
preempt_disable();
count = __this_cpu_read(*fbc->counters) + amount;
if (count >= batch || count <= -batch) {
raw_spin_lock(&fbc->lock);
fbc->count += count;
__this_cpu_write(*fbc->counters, 0);
raw_spin_unlock(&fbc->lock);
} else {
__this_cpu_write(*fbc->counters, count);
}
preempt_enable();
}
EXPORT_SYMBOL(__percpu_counter_add);
/*
* Add up all the per-cpu counts, return the result. This is a more accurate
* but much slower version of percpu_counter_read_positive()
*/
s64 __percpu_counter_sum(struct percpu_counter *fbc)
{
s64 ret;
int cpu;
raw_spin_lock(&fbc->lock);
ret = fbc->count;
for_each_online_cpu(cpu) {
s32 *pcount = per_cpu_ptr(fbc->counters, cpu);
ret += *pcount;
}
raw_spin_unlock(&fbc->lock);
return ret;
}
EXPORT_SYMBOL(__percpu_counter_sum);
int __percpu_counter_init(struct percpu_counter *fbc, s64 amount,
struct lock_class_key *key)
{
raw_spin_lock_init(&fbc->lock);
lockdep_set_class(&fbc->lock, key);
fbc->count = amount;
fbc->counters = alloc_percpu(s32);
if (!fbc->counters)
return -ENOMEM;
debug_percpu_counter_activate(fbc);
#ifdef CONFIG_HOTPLUG_CPU
INIT_LIST_HEAD(&fbc->list);
mutex_lock(&percpu_counters_lock);
list_add(&fbc->list, &percpu_counters);
mutex_unlock(&percpu_counters_lock);
#endif
return 0;
}
EXPORT_SYMBOL(__percpu_counter_init);
void percpu_counter_destroy(struct percpu_counter *fbc)
{
if (!fbc->counters)
return;
debug_percpu_counter_deactivate(fbc);
#ifdef CONFIG_HOTPLUG_CPU
mutex_lock(&percpu_counters_lock);
list_del(&fbc->list);
mutex_unlock(&percpu_counters_lock);
#endif
free_percpu(fbc->counters);
fbc->counters = NULL;
}
EXPORT_SYMBOL(percpu_counter_destroy);
int percpu_counter_batch __read_mostly = 32;
EXPORT_SYMBOL(percpu_counter_batch);
static void compute_batch_value(void)
{
int nr = num_online_cpus();
percpu_counter_batch = max(32, nr*2);
}
static int __cpuinit percpu_counter_hotcpu_callback(struct notifier_block *nb,
unsigned long action, void *hcpu)
{
#ifdef CONFIG_HOTPLUG_CPU
unsigned int cpu;
struct percpu_counter *fbc;
compute_batch_value();
if (action != CPU_DEAD)
return NOTIFY_OK;
cpu = (unsigned long)hcpu;
mutex_lock(&percpu_counters_lock);
list_for_each_entry(fbc, &percpu_counters, list) {
s32 *pcount;
unsigned long flags;
raw_spin_lock_irqsave(&fbc->lock, flags);
pcount = per_cpu_ptr(fbc->counters, cpu);
fbc->count += *pcount;
*pcount = 0;
raw_spin_unlock_irqrestore(&fbc->lock, flags);
}
mutex_unlock(&percpu_counters_lock);
#endif
return NOTIFY_OK;
}
/*
* Compare counter against given value.
* Return 1 if greater, 0 if equal and -1 if less
*/
int percpu_counter_compare(struct percpu_counter *fbc, s64 rhs)
{
s64 count;
count = percpu_counter_read(fbc);
/* Check to see if rough count will be sufficient for comparison */
if (abs(count - rhs) > (percpu_counter_batch*num_online_cpus())) {
if (count > rhs)
return 1;
else
return -1;
}
/* Need to use precise count */
count = percpu_counter_sum(fbc);
if (count > rhs)
return 1;
else if (count < rhs)
return -1;
else
return 0;
}
EXPORT_SYMBOL(percpu_counter_compare);
static int __init percpu_counter_startup(void)
{
compute_batch_value();
hotcpu_notifier(percpu_counter_hotcpu_callback, 0);
return 0;
}
module_init(percpu_counter_startup);
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