* [PATCH 1/3] x86: hpet: print HPET registers during setup (if hpet=verbose is used)
2009-02-20 23:07 [PATCH 0/3] x86: dish of assorted hpet patches Andreas Herrmann
@ 2009-02-20 23:09 ` Andreas Herrmann
2009-02-20 23:10 ` [PATCH 2/3] x86: hpet: provide separate functions to stop and start the counter Andreas Herrmann
` (2 subsequent siblings)
3 siblings, 0 replies; 6+ messages in thread
From: Andreas Herrmann @ 2009-02-20 23:09 UTC (permalink / raw)
To: Ingo Molnar, Thomas Gleixner
Cc: linux-kernel, Mark Hounschell, Borislav Petkov
Impact: provide verbose HPET information
Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com>
---
Documentation/kernel-parameters.txt | 4 ++-
arch/x86/kernel/hpet.c | 45 +++++++++++++++++++++++++++++++++++
2 files changed, 48 insertions(+), 1 deletions(-)
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index b182626..01379a8 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -492,10 +492,12 @@ and is between 256 and 4096 characters. It is defined in the file
Default: 64
hpet= [X86-32,HPET] option to control HPET usage
- Format: { enable (default) | disable | force }
+ Format: { enable (default) | disable | force |
+ verbose }
disable: disable HPET and use PIT instead
force: allow force enabled of undocumented chips (ICH4,
VIA, nVidia)
+ verbose: show contents of HPET registers during setup
com20020= [HW,NET] ARCnet - COM20020 chipset
Format:
diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c
index a00545f..84450b1 100644
--- a/arch/x86/kernel/hpet.c
+++ b/arch/x86/kernel/hpet.c
@@ -80,6 +80,7 @@ static inline void hpet_clear_mapping(void)
*/
static int boot_hpet_disable;
int hpet_force_user;
+static int hpet_verbose;
static int __init hpet_setup(char *str)
{
@@ -88,6 +89,8 @@ static int __init hpet_setup(char *str)
boot_hpet_disable = 1;
if (!strncmp("force", str, 5))
hpet_force_user = 1;
+ if (!strncmp("verbose", str, 7))
+ hpet_verbose = 1;
}
return 1;
}
@@ -119,6 +122,43 @@ int is_hpet_enabled(void)
}
EXPORT_SYMBOL_GPL(is_hpet_enabled);
+static void _hpet_print_config(const char *function, int line)
+{
+ u32 i, timers, l, h;
+ printk(KERN_INFO "hpet: %s(%d):\n", function, line);
+ l = hpet_readl(HPET_ID);
+ h = hpet_readl(HPET_PERIOD);
+ timers = ((l & HPET_ID_NUMBER) >> HPET_ID_NUMBER_SHIFT) + 1;
+ printk(KERN_INFO "hpet: ID: 0x%x, PERIOD: 0x%x\n", l, h);
+ l = hpet_readl(HPET_CFG);
+ h = hpet_readl(HPET_STATUS);
+ printk(KERN_INFO "hpet: CFG: 0x%x, STATUS: 0x%x\n", l, h);
+ l = hpet_readl(HPET_COUNTER);
+ h = hpet_readl(HPET_COUNTER+4);
+ printk(KERN_INFO "hpet: COUNTER_l: 0x%x, COUNTER_h: 0x%x\n", l, h);
+
+ for (i = 0; i < timers; i++) {
+ l = hpet_readl(HPET_Tn_CFG(i));
+ h = hpet_readl(HPET_Tn_CFG(i)+4);
+ printk(KERN_INFO "hpet: T%d: CFG_l: 0x%x, CFG_h: 0x%x\n",
+ i, l, h);
+ l = hpet_readl(HPET_Tn_CMP(i));
+ h = hpet_readl(HPET_Tn_CMP(i)+4);
+ printk(KERN_INFO "hpet: T%d: CMP_l: 0x%x, CMP_h: 0x%x\n",
+ i, l, h);
+ l = hpet_readl(HPET_Tn_ROUTE(i));
+ h = hpet_readl(HPET_Tn_ROUTE(i)+4);
+ printk(KERN_INFO "hpet: T%d ROUTE_l: 0x%x, ROUTE_h: 0x%x\n",
+ i, l, h);
+ }
+}
+
+#define hpet_print_config() \
+do { \
+ if (hpet_verbose) \
+ _hpet_print_config(__FUNCTION__, __LINE__); \
+} while (0)
+
/*
* When the hpet driver (/dev/hpet) is enabled, we need to reserve
* timer 0 and timer 1 in case of RTC emulation.
@@ -282,6 +322,7 @@ static void hpet_set_mode(enum clock_event_mode mode,
hpet_writel(cmp, HPET_Tn_CMP(timer));
udelay(1);
hpet_writel((unsigned long) delta, HPET_Tn_CMP(timer));
+ hpet_print_config();
break;
case CLOCK_EVT_MODE_ONESHOT:
@@ -308,6 +349,7 @@ static void hpet_set_mode(enum clock_event_mode mode,
irq_set_affinity(hdev->irq, cpumask_of(hdev->cpu));
enable_irq(hdev->irq);
}
+ hpet_print_config();
break;
}
}
@@ -526,6 +568,7 @@ static void hpet_msi_capability_lookup(unsigned int start_timer)
num_timers = ((id & HPET_ID_NUMBER) >> HPET_ID_NUMBER_SHIFT);
num_timers++; /* Value read out starts from 0 */
+ hpet_print_config();
hpet_devs = kzalloc(sizeof(struct hpet_dev) * num_timers, GFP_KERNEL);
if (!hpet_devs)
@@ -793,6 +836,7 @@ int __init hpet_enable(void)
* information and the number of channels
*/
id = hpet_readl(HPET_ID);
+ hpet_print_config();
#ifdef CONFIG_HPET_EMULATE_RTC
/*
@@ -845,6 +889,7 @@ static __init int hpet_late_init(void)
return -ENODEV;
hpet_reserve_platform_timers(hpet_readl(HPET_ID));
+ hpet_print_config();
for_each_online_cpu(cpu) {
hpet_cpuhp_notify(NULL, CPU_ONLINE, (void *)(long)cpu);
--
1.6.1.3
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH 2/3] x86: hpet: provide separate functions to stop and start the counter
2009-02-20 23:07 [PATCH 0/3] x86: dish of assorted hpet patches Andreas Herrmann
2009-02-20 23:09 ` [PATCH 1/3] x86: hpet: print HPET registers during setup (if hpet=verbose is used) Andreas Herrmann
@ 2009-02-20 23:10 ` Andreas Herrmann
2009-02-20 23:16 ` [PATCH 3/3] x86: hpet: stop HPET_COUNTER when programming periodic mode Andreas Herrmann
2009-02-22 17:04 ` [PATCH 0/3] x86: dish of assorted hpet patches Ingo Molnar
3 siblings, 0 replies; 6+ messages in thread
From: Andreas Herrmann @ 2009-02-20 23:10 UTC (permalink / raw)
To: Ingo Molnar, Thomas Gleixner
Cc: linux-kernel, Mark Hounschell, Borislav Petkov
By splitting up existing hpet_start_counter function.
Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com>
---
arch/x86/kernel/hpet.c | 22 ++++++++++++++++------
1 files changed, 16 insertions(+), 6 deletions(-)
diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c
index 84450b1..20acc6a 100644
--- a/arch/x86/kernel/hpet.c
+++ b/arch/x86/kernel/hpet.c
@@ -231,27 +231,37 @@ static struct clock_event_device hpet_clockevent = {
.rating = 50,
};
-static void hpet_start_counter(void)
+static void hpet_stop_counter(void)
{
unsigned long cfg = hpet_readl(HPET_CFG);
-
cfg &= ~HPET_CFG_ENABLE;
hpet_writel(cfg, HPET_CFG);
hpet_writel(0, HPET_COUNTER);
hpet_writel(0, HPET_COUNTER + 4);
+}
+
+static void hpet_start_counter(void)
+{
+ unsigned long cfg = hpet_readl(HPET_CFG);
cfg |= HPET_CFG_ENABLE;
hpet_writel(cfg, HPET_CFG);
}
+static void hpet_restart_counter(void)
+{
+ hpet_stop_counter();
+ hpet_start_counter();
+}
+
static void hpet_resume_device(void)
{
force_hpet_resume();
}
-static void hpet_restart_counter(void)
+static void hpet_resume_counter(void)
{
hpet_resume_device();
- hpet_start_counter();
+ hpet_restart_counter();
}
static void hpet_enable_legacy_int(void)
@@ -738,7 +748,7 @@ static struct clocksource clocksource_hpet = {
.mask = HPET_MASK,
.shift = HPET_SHIFT,
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
- .resume = hpet_restart_counter,
+ .resume = hpet_resume_counter,
#ifdef CONFIG_X86_64
.vread = vread_hpet,
#endif
@@ -750,7 +760,7 @@ static int hpet_clocksource_register(void)
cycle_t t1;
/* Start the counter */
- hpet_start_counter();
+ hpet_restart_counter();
/* Verify whether hpet counter works */
t1 = read_hpet();
--
1.6.1.3
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH 3/3] x86: hpet: stop HPET_COUNTER when programming periodic mode
2009-02-20 23:07 [PATCH 0/3] x86: dish of assorted hpet patches Andreas Herrmann
2009-02-20 23:09 ` [PATCH 1/3] x86: hpet: print HPET registers during setup (if hpet=verbose is used) Andreas Herrmann
2009-02-20 23:10 ` [PATCH 2/3] x86: hpet: provide separate functions to stop and start the counter Andreas Herrmann
@ 2009-02-20 23:16 ` Andreas Herrmann
2009-02-24 6:25 ` Andreas Herrmann
2009-02-22 17:04 ` [PATCH 0/3] x86: dish of assorted hpet patches Ingo Molnar
3 siblings, 1 reply; 6+ messages in thread
From: Andreas Herrmann @ 2009-02-20 23:16 UTC (permalink / raw)
To: Ingo Molnar, Thomas Gleixner
Cc: linux-kernel, Mark Hounschell, Borislav Petkov
Impact: fix system hang on some systems operating with HZ_1000
On a system that stalled with HZ_1000, the first value written to
T0_CMP (when the main counter was not stopped) did not trigger an
interrupt. Instead after the main counter wrapped around (after
several minutes) an interrupt was triggered and afterwards the
periodic interrupt took effect.
This can be fixed by implementing HPET spec recommendation for
programming the periodic mode (i.e. stopping the main counter).
Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com>
---
arch/x86/kernel/hpet.c | 13 +++----------
1 files changed, 3 insertions(+), 10 deletions(-)
diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c
index 20acc6a..46be008 100644
--- a/arch/x86/kernel/hpet.c
+++ b/arch/x86/kernel/hpet.c
@@ -309,29 +309,22 @@ static int hpet_setup_msi_irq(unsigned int irq);
static void hpet_set_mode(enum clock_event_mode mode,
struct clock_event_device *evt, int timer)
{
- unsigned long cfg, cmp, now;
+ unsigned long cfg;
uint64_t delta;
switch (mode) {
case CLOCK_EVT_MODE_PERIODIC:
+ hpet_stop_counter();
delta = ((uint64_t)(NSEC_PER_SEC/HZ)) * evt->mult;
delta >>= evt->shift;
- now = hpet_readl(HPET_COUNTER);
- cmp = now + (unsigned long) delta;
cfg = hpet_readl(HPET_Tn_CFG(timer));
/* Make sure we use edge triggered interrupts */
cfg &= ~HPET_TN_LEVEL;
cfg |= HPET_TN_ENABLE | HPET_TN_PERIODIC |
HPET_TN_SETVAL | HPET_TN_32BIT;
hpet_writel(cfg, HPET_Tn_CFG(timer));
- /*
- * The first write after writing TN_SETVAL to the
- * config register sets the counter value, the second
- * write sets the period.
- */
- hpet_writel(cmp, HPET_Tn_CMP(timer));
- udelay(1);
hpet_writel((unsigned long) delta, HPET_Tn_CMP(timer));
+ hpet_start_counter();
hpet_print_config();
break;
--
1.6.1.3
^ permalink raw reply related [flat|nested] 6+ messages in thread