| Message ID | 1502232075-23832-3-git-send-email-srinivas.pandruvada@linux.intel.com (mailing list archive) |
|---|---|
| State | Changes Requested, archived |
| Headers | show |
On Wednesday, August 9, 2017 12:41:15 AM CEST Srinivas Pandruvada wrote: > For SoC to achieve its lowest power platform idle state a set of hardware > preconditions must be met. These preconditions or constraints can be > obtained by issuing a device specific method (_DSM) with function "1". > Refer to the document provided in the link below. > > Here during initialization (from attach() callback of LPS0 device), invoke > function 1 to get the device constraints. Each enabled constraint is > stored in a table. > > The devices in this table are used to check whether they were in required > minimum state, while entering suspend. This check is done from platform > freeze wake() callback, only when /sys/power/pm_debug_messages attribute > is non zero. > > If any constraint is not met and device is ACPI power managed then it > prints the device name to kernel logs. > > Also if debug is enabled in acpi/sleep.c, the constraint table and state > of each device on wake is dumped in kernel logs. > > Link: http://www.uefi.org/sites/default/files/resources/Intel_ACPI_Low_Power_S0_Idle.pdf > Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> > --- > drivers/acpi/sleep.c | 162 +++++++++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 162 insertions(+) > > diff --git a/drivers/acpi/sleep.c b/drivers/acpi/sleep.c > index 2b881de..b3ef577 100644 > --- a/drivers/acpi/sleep.c > +++ b/drivers/acpi/sleep.c > @@ -669,6 +669,7 @@ static const struct acpi_device_id lps0_device_ids[] = { [cut] > > @@ -773,6 +933,8 @@ static void acpi_freeze_wake(void) > */ > if (acpi_sci_irq_valid() && > !irqd_is_wakeup_armed(irq_get_irq_data(acpi_sci_irq))) { > + if (pm_debug_messages_enabled()) > + lpi_check_constraints(); I'm not sure why you only want to check the constraints when we do the _cancel_wakeup() thing. IMO the check is relevant regardless of whether or not the wakeup was via ACPI. > pm_system_cancel_wakeup(); > s2idle_wakeup = true; > } >
On Thu, 2017-08-10 at 01:17 +0200, Rafael J. Wysocki wrote: > On Wednesday, August 9, 2017 12:41:15 AM CEST Srinivas Pandruvada > wrote: > > > > For SoC to achieve its lowest power platform idle state a set of > > hardware > > preconditions must be met. These preconditions or constraints can > > be > > obtained by issuing a device specific method (_DSM) with function > > "1". > > Refer to the document provided in the link below. > > > > Here during initialization (from attach() callback of LPS0 device), > > invoke > > function 1 to get the device constraints. Each enabled constraint > > is > > stored in a table. > > > > The devices in this table are used to check whether they were in > > required > > minimum state, while entering suspend. This check is done from > > platform > > freeze wake() callback, only when /sys/power/pm_debug_messages > > attribute > > is non zero. > > > > If any constraint is not met and device is ACPI power managed then > > it > > prints the device name to kernel logs. > > > > Also if debug is enabled in acpi/sleep.c, the constraint table and > > state > > of each device on wake is dumped in kernel logs. > > > > Link: http://www.uefi.org/sites/default/files/resources/Intel_ACPI_ > > Low_Power_S0_Idle.pdf > > Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel > > .com> > > --- > > drivers/acpi/sleep.c | 162 > > +++++++++++++++++++++++++++++++++++++++++++++++++++ > > 1 file changed, 162 insertions(+) > > > > diff --git a/drivers/acpi/sleep.c b/drivers/acpi/sleep.c > > index 2b881de..b3ef577 100644 > > --- a/drivers/acpi/sleep.c > > +++ b/drivers/acpi/sleep.c > > @@ -669,6 +669,7 @@ static const struct acpi_device_id > > lps0_device_ids[] = { > [cut] > > > > > > > @@ -773,6 +933,8 @@ static void acpi_freeze_wake(void) > > */ > > if (acpi_sci_irq_valid() && > > !irqd_is_wakeup_armed(irq_get_irq_data(acpi_sci_irq))) > > { > > + if (pm_debug_messages_enabled()) > > + lpi_check_constraints(); > I'm not sure why you only want to check the constraints when we do > the > _cancel_wakeup() thing. > > IMO the check is relevant regardless of whether or not the wakeup was > via ACPI. OK. I will move out of this if block. Thanks, Srinivas > > > > > pm_system_cancel_wakeup(); > > s2idle_wakeup = true; > > } > > >
> -----Original Message----- > From: Srinivas Pandruvada [mailto:srinivas.pandruvada@linux.intel.com] > Sent: Tuesday, August 8, 2017 5:41 PM > To: rjw@rjwysocki.net; lenb@kernel.org > Cc: linux-pm@vger.kernel.org; Limonciello, Mario <Mario_Limonciello@Dell.com>; > linux-kernel@vger.kernel.org; linux-acpi@vger.kernel.org; lukas@wunner.de; > Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> > Subject: [PATCH v2 2/2] ACPI / Sleep: Check low power idle constraints for debug > only > > For SoC to achieve its lowest power platform idle state a set of hardware > preconditions must be met. These preconditions or constraints can be > obtained by issuing a device specific method (_DSM) with function "1". > Refer to the document provided in the link below. > > Here during initialization (from attach() callback of LPS0 device), invoke > function 1 to get the device constraints. Each enabled constraint is > stored in a table. > > The devices in this table are used to check whether they were in required > minimum state, while entering suspend. This check is done from platform > freeze wake() callback, only when /sys/power/pm_debug_messages attribute > is non zero. > > If any constraint is not met and device is ACPI power managed then it > prints the device name to kernel logs. > > Also if debug is enabled in acpi/sleep.c, the constraint table and state > of each device on wake is dumped in kernel logs. > > Link: > http://www.uefi.org/sites/default/files/resources/Intel_ACPI_Low_Power_S0_Idle. > pdf > Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> > --- > drivers/acpi/sleep.c | 162 > +++++++++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 162 insertions(+) > > diff --git a/drivers/acpi/sleep.c b/drivers/acpi/sleep.c > index 2b881de..b3ef577 100644 > --- a/drivers/acpi/sleep.c > +++ b/drivers/acpi/sleep.c > @@ -669,6 +669,7 @@ static const struct acpi_device_id lps0_device_ids[] = { > > #define ACPI_LPS0_DSM_UUID "c4eb40a0-6cd2-11e2-bcfd-0800200c9a66" > > +#define ACPI_LPS0_GET_DEVICE_CONSTRAINTS 1 > #define ACPI_LPS0_SCREEN_OFF 3 > #define ACPI_LPS0_SCREEN_ON 4 > #define ACPI_LPS0_ENTRY 5 > @@ -680,6 +681,162 @@ static acpi_handle lps0_device_handle; > static guid_t lps0_dsm_guid; > static char lps0_dsm_func_mask; > > +/* Device constraint entry structure */ > +struct lpi_device_info { > + char *name; > + int enabled; > + union acpi_object *package; > +}; > + > +/* Constraint package structure */ > +struct lpi_device_constraint { > + int uid; > + int min_dstate; > + int function_states; > +}; > + > +struct lpi_constraints { > + char *name; > + int min_dstate; > +}; > + > +static struct lpi_constraints *lpi_constraints_table; > +static int lpi_constraints_table_size; > + > +static void lpi_device_get_constraints(void) > +{ > + union acpi_object *out_obj; > + int i; > + > + out_obj = acpi_evaluate_dsm_typed(lps0_device_handle, &lps0_dsm_guid, > + 1, > ACPI_LPS0_GET_DEVICE_CONSTRAINTS, > + NULL, ACPI_TYPE_PACKAGE); > + > + acpi_handle_debug(lps0_device_handle, "_DSM function 1 eval %s\n", > + out_obj ? "successful" : "failed"); > + > + if (!out_obj) > + return; > + > + lpi_constraints_table = kcalloc(out_obj->package.count, > + sizeof(*lpi_constraints_table), > + GFP_KERNEL); > + if (!lpi_constraints_table) > + goto free_acpi_buffer; > + > + pr_debug("LPI: constraints dump begin\n"); > + for (i = 0; i < out_obj->package.count; i++) { > + union acpi_object *package = &out_obj->package.elements[i]; > + struct lpi_device_info info = { }; > + int package_count = 0, j; > + > + if (!package) > + continue; > + > + for (j = 0; j < package->package.count; ++j) { > + union acpi_object *element = > + &(package->package.elements[j]); > + > + switch (element->type) { > + case ACPI_TYPE_INTEGER: > + info.enabled = element->integer.value; > + break; > + case ACPI_TYPE_STRING: > + info.name = element->string.pointer; > + break; > + case ACPI_TYPE_PACKAGE: > + package_count = element->package.count; > + info.package = element->package.elements; > + break; > + } > + } > + > + if (!info.enabled || !info.package || !info.name) > + continue; > + > + lpi_constraints_table[lpi_constraints_table_size].name = > + kstrdup(info.name, GFP_KERNEL); > + if (!lpi_constraints_table[lpi_constraints_table_size].name) > + goto free_constraints; > + > + pr_debug("index:%d Name:%s\n", i, info.name); > + > + for (j = 0; j < package_count; ++j) { > + union acpi_object *info_obj = &info.package[j]; > + union acpi_object *cnstr_pkg; > + union acpi_object *obj; > + struct lpi_device_constraint dev_info; > + > + switch (info_obj->type) { > + case ACPI_TYPE_INTEGER: > + /* version */ > + break; > + case ACPI_TYPE_PACKAGE: > + if (info_obj->package.count < 2) > + break; > + > + cnstr_pkg = info_obj->package.elements; > + obj = &cnstr_pkg[0]; > + dev_info.uid = obj->integer.value; > + obj = &cnstr_pkg[1]; > + dev_info.min_dstate = obj->integer.value; > + pr_debug("uid %d min_dstate %d\n", > + dev_info.uid, > + dev_info.min_dstate); > + lpi_constraints_table[ > + lpi_constraints_table_size].min_dstate = > + dev_info.min_dstate; > + break; > + } > + } > + > + lpi_constraints_table_size++; > + } > + > + pr_debug("LPI: constraints dump end\n"); > +free_acpi_buffer: > + ACPI_FREE(out_obj); > + return; > + > +free_constraints: > + ACPI_FREE(out_obj); > + for (i = 0; i < lpi_constraints_table_size; ++i) > + kfree(lpi_constraints_table[i].name); > + kfree(lpi_constraints_table); > + lpi_constraints_table_size = 0; > +} > + > +static void lpi_check_constraints(void) > +{ > + int i; > + > + for (i = 0; i < lpi_constraints_table_size; ++i) { > + acpi_handle handle; > + struct acpi_device *adev; > + int state, ret; > + > + if (ACPI_FAILURE(acpi_get_handle(NULL, > + lpi_constraints_table[i].name, > + &handle))) > + continue; > + > + if (acpi_bus_get_device(handle, &adev)) > + continue; > + > + ret = acpi_device_get_power(adev, &state); > + if (!ret) > + pr_debug("LPI: %s required min power state %d, current > power state %d, real power state %d\n", > + lpi_constraints_table[i].name, > + lpi_constraints_table[i].min_dstate, > + adev->power.state, state); Isn't this superfluous to be showing the state returned from acpi_device_get_power and also probing directly at the state? You can't just rely on the information you got back from apci_device_get_power? > + > + if (adev->flags.power_manageable && adev->power.state < > + lpi_constraints_table[i].min_dstate) > + pr_info("LPI: Constraint [%s] not matched\n", > + lpi_constraints_table[i].name); Similarly here, can't you just compare against &state instead? > + } > +} > + > static void acpi_sleep_run_lps0_dsm(unsigned int func) > { > union acpi_object *out_obj; > @@ -729,6 +886,9 @@ static int lps0_device_attach(struct acpi_device *adev, > "_DSM function 0 evaluation failed\n"); > } > ACPI_FREE(out_obj); > + > + lpi_device_get_constraints(); > + > return 0; > } > > @@ -773,6 +933,8 @@ static void acpi_freeze_wake(void) > */ > if (acpi_sci_irq_valid() && > !irqd_is_wakeup_armed(irq_get_irq_data(acpi_sci_irq))) { > + if (pm_debug_messages_enabled()) > + lpi_check_constraints(); > pm_system_cancel_wakeup(); > s2idle_wakeup = true; > } > -- > 2.7.5
On Thu, 2017-08-10 at 22:07 +0000, Mario.Limonciello@dell.com wrote: > > > > > [...] > > + > > + ret = acpi_device_get_power(adev, &state); > > + if (!ret) > > + pr_debug("LPI: %s required min power state > > %d, current > > power state %d, real power state %d\n", > > + lpi_constraints_table[i].name, > > + lpi_constraints_table[i].min_dsta > > te, > > + adev->power.state, state); > Isn't this superfluous to be showing the state returned from > acpi_device_get_power and > also probing directly at the state? You can't just rely on the > information you got > back from apci_device_get_power? They can be different as one is real power state and the other is what was set. For example on Dell 9365 it shows [ 1924.393653] LPI: \_SB.PCI0.XHC required min power state 3, current power state 3, real power state 255 > > > > > + > > + if (adev->flags.power_manageable && adev- > > >power.state < > > + lpi_constraints_table[i].m > > in_dstate) > > + pr_info("LPI: Constraint [%s] not > > matched\n", > > + lpi_constraints_table[i].name); > Similarly here, can't you just compare against &state instead? > The problem then the check will fail for XHCI on Dell 9365. So not using "state". Thanks, Srinivas > > > > + } > > +} > > + > > static void acpi_sleep_run_lps0_dsm(unsigned int func) > > { > > union acpi_object *out_obj; > > @@ -729,6 +886,9 @@ static int lps0_device_attach(struct > > acpi_device *adev, > > "_DSM function 0 evaluation > > failed\n"); > > } > > ACPI_FREE(out_obj); > > + > > + lpi_device_get_constraints(); > > + > > return 0; > > } > > > > @@ -773,6 +933,8 @@ static void acpi_freeze_wake(void) > > */ > > if (acpi_sci_irq_valid() && > > !irqd_is_wakeup_armed(irq_get_irq_data(acpi_sci_irq))) > > { > > + if (pm_debug_messages_enabled()) > > + lpi_check_constraints(); > > pm_system_cancel_wakeup(); > > s2idle_wakeup = true; > > } > > -- > > 2.7.5
> -----Original Message----- > From: Srinivas Pandruvada [mailto:srinivas.pandruvada@linux.intel.com] > Sent: Thursday, August 10, 2017 5:54 PM > To: Limonciello, Mario <Mario_Limonciello@Dell.com>; rjw@rjwysocki.net; > lenb@kernel.org > Cc: linux-pm@vger.kernel.org; linux-kernel@vger.kernel.org; linux- > acpi@vger.kernel.org; lukas@wunner.de > Subject: Re: [PATCH v2 2/2] ACPI / Sleep: Check low power idle constraints for > debug only > > On Thu, 2017-08-10 at 22:07 +0000, Mario.Limonciello@dell.com wrote: > > > > > > > > > [...] > > > > + > > > + ret = acpi_device_get_power(adev, &state); > > > + if (!ret) > > > + pr_debug("LPI: %s required min power state > > > %d, current > > > power state %d, real power state %d\n", > > > + lpi_constraints_table[i].name, > > > + lpi_constraints_table[i].min_dsta > > > te, > > > + adev->power.state, state); > > Isn't this superfluous to be showing the state returned from > > acpi_device_get_power and > > also probing directly at the state? You can't just rely on the > > information you got > > back from apci_device_get_power? > They can be different as one is real power state and the other is what > was set. > For example on Dell 9365 it shows > > [ 1924.393653] LPI: \_SB.PCI0.XHC required min power state 3, current > power state 3, real power state 255 > Isn't 255 ACPI_STATE_UNKNOWN? That makes it seem like it is a logic problem in acpi_device_get_power (or somewhere down the chain) doesn't it? > > > > > > > > + > > > + if (adev->flags.power_manageable && adev- > > > >power.state < > > > + lpi_constraints_table[i].m > > > in_dstate) > > > + pr_info("LPI: Constraint [%s] not > > > matched\n", > > > + lpi_constraints_table[i].name); > > Similarly here, can't you just compare against &state instead? > > > The problem then the check will fail for XHCI on Dell 9365. So not > using "state". > > Thanks, > Srinivas > > > > > > + } > > > +} > > > + > > > static void acpi_sleep_run_lps0_dsm(unsigned int func) > > > { > > > union acpi_object *out_obj; > > > @@ -729,6 +886,9 @@ static int lps0_device_attach(struct > > > acpi_device *adev, > > > "_DSM function 0 evaluation > > > failed\n"); > > > } > > > ACPI_FREE(out_obj); > > > + > > > + lpi_device_get_constraints(); > > > + > > > return 0; > > > } > > > > > > @@ -773,6 +933,8 @@ static void acpi_freeze_wake(void) > > > */ > > > if (acpi_sci_irq_valid() && > > > !irqd_is_wakeup_armed(irq_get_irq_data(acpi_sci_irq))) > > > { > > > + if (pm_debug_messages_enabled()) > > > + lpi_check_constraints(); > > > pm_system_cancel_wakeup(); > > > s2idle_wakeup = true; > > > } > > > -- > > > 2.7.5
On Fri, 2017-08-11 at 14:43 +0000, Mario.Limonciello@dell.com wrote: > > > > -----Original Message----- > > From: Srinivas Pandruvada [mailto:srinivas.pandruvada@linux.intel.c > > om] > > Sent: Thursday, August 10, 2017 5:54 PM > > To: Limonciello, Mario <Mario_Limonciello@Dell.com>; rjw@rjwysocki. > > net; > > lenb@kernel.org > > Cc: linux-pm@vger.kernel.org; linux-kernel@vger.kernel.org; linux- > > acpi@vger.kernel.org; lukas@wunner.de > > Subject: Re: [PATCH v2 2/2] ACPI / Sleep: Check low power idle > > constraints for > > debug only > > > > On Thu, 2017-08-10 at 22:07 +0000, Mario.Limonciello@dell.com > > wrote: > > > > > > > > > > > > > > > > > > > > [...] > > > > > > > > > > > > > + > > > > + ret = acpi_device_get_power(adev, &state); > > > > + if (!ret) > > > > + pr_debug("LPI: %s required min power > > > > state > > > > %d, current > > > > power state %d, real power state %d\n", > > > > + lpi_constraints_table[i].name > > > > , > > > > + lpi_constraints_table[i].min_ > > > > dsta > > > > te, > > > > + adev->power.state, state); > > > Isn't this superfluous to be showing the state returned from > > > acpi_device_get_power and > > > also probing directly at the state? You can't just rely on the > > > information you got > > > back from apci_device_get_power? > > They can be different as one is real power state and the other is > > what > > was set. > > For example on Dell 9365 it shows > > > > [ 1924.393653] LPI: \_SB.PCI0.XHC required min power state 3, > > current > > power state 3, real power state 255 > > > Isn't 255 ACPI_STATE_UNKNOWN? That makes it seem like it > is a logic problem in acpi_device_get_power (or somewhere down the > chain) > doesn't it? There is no _PSC for XHC device. So it will return unknown. This is an optional object, so I think that dumping the status is fine, but matching with output of acpi_device_get_power() as it relies on _PSC is not correct for the constraint. Thanks, Srinivas > > > > > > > > > > > > > > > > > > > > > + > > > > + if (adev->flags.power_manageable && adev- > > > > > > > > > > power.state < > > > > + lpi_constraints_table[ > > > > i].m > > > > in_dstate) > > > > + pr_info("LPI: Constraint [%s] not > > > > matched\n", > > > > + lpi_constraints_table[i].name > > > > ); > > > Similarly here, can't you just compare against &state instead? > > > > > The problem then the check will fail for XHCI on Dell 9365. So not > > using "state". > > > > Thanks, > > Srinivas > > > > > > > > > > > > > > > + } > > > > +} > > > > + > > > > static void acpi_sleep_run_lps0_dsm(unsigned int func) > > > > { > > > > union acpi_object *out_obj; > > > > @@ -729,6 +886,9 @@ static int lps0_device_attach(struct > > > > acpi_device *adev, > > > > "_DSM function 0 evaluation > > > > failed\n"); > > > > } > > > > ACPI_FREE(out_obj); > > > > + > > > > + lpi_device_get_constraints(); > > > > + > > > > return 0; > > > > } > > > > > > > > @@ -773,6 +933,8 @@ static void acpi_freeze_wake(void) > > > > */ > > > > if (acpi_sci_irq_valid() && > > > > !irqd_is_wakeup_armed(irq_get_irq_data(acpi_sci_ir > > > > q))) > > > > { > > > > + if (pm_debug_messages_enabled()) > > > > + lpi_check_constraints(); > > > > pm_system_cancel_wakeup(); > > > > s2idle_wakeup = true; > > > > } > > > > -- > > > > 2.7.5
On Friday, August 11, 2017 6:18:50 PM CEST Srinivas Pandruvada wrote: > On Fri, 2017-08-11 at 14:43 +0000, Mario.Limonciello@dell.com wrote: > > > > > > -----Original Message----- > > > From: Srinivas Pandruvada [mailto:srinivas.pandruvada@linux.intel.c > > > om] > > > Sent: Thursday, August 10, 2017 5:54 PM > > > To: Limonciello, Mario <Mario_Limonciello@Dell.com>; rjw@rjwysocki. > > > net; > > > lenb@kernel.org > > > Cc: linux-pm@vger.kernel.org; linux-kernel@vger.kernel.org; linux- > > > acpi@vger.kernel.org; lukas@wunner.de > > > Subject: Re: [PATCH v2 2/2] ACPI / Sleep: Check low power idle > > > constraints for > > > debug only > > > > > > On Thu, 2017-08-10 at 22:07 +0000, Mario.Limonciello@dell.com > > > wrote: > > > > > > > > > > > > > > > > > > > > > > > > > > [...] > > > > > > > > > > > > > > > > > + > > > > > + ret = acpi_device_get_power(adev, &state); > > > > > + if (!ret) > > > > > + pr_debug("LPI: %s required min power > > > > > state > > > > > %d, current > > > > > power state %d, real power state %d\n", > > > > > + lpi_constraints_table[i].name > > > > > , > > > > > + lpi_constraints_table[i].min_ > > > > > dsta > > > > > te, > > > > > + adev->power.state, state); > > > > Isn't this superfluous to be showing the state returned from > > > > acpi_device_get_power and > > > > also probing directly at the state? You can't just rely on the > > > > information you got > > > > back from apci_device_get_power? > > > They can be different as one is real power state and the other is > > > what > > > was set. > > > For example on Dell 9365 it shows > > > > > > [ 1924.393653] LPI: \_SB.PCI0.XHC required min power state 3, > > > current > > > power state 3, real power state 255 > > > > > Isn't 255 ACPI_STATE_UNKNOWN? That makes it seem like it > > is a logic problem in acpi_device_get_power (or somewhere down the > > chain) > > doesn't it? > There is no _PSC for XHC device. So it will return unknown. This is an > optional object, so I think that dumping the status is fine, but > matching with output of acpi_device_get_power() as it relies on _PSC is > not correct for the constraint. Right. Moreover, acpi_device_get_power() is basically mostly intended for initialization, so the constraint should be matched against power.state, as that's the current ACPI power state of the device as far as the kernel can say. Thanks, Rafael
diff --git a/drivers/acpi/sleep.c b/drivers/acpi/sleep.c index 2b881de..b3ef577 100644 --- a/drivers/acpi/sleep.c +++ b/drivers/acpi/sleep.c @@ -669,6 +669,7 @@ static const struct acpi_device_id lps0_device_ids[] = { #define ACPI_LPS0_DSM_UUID "c4eb40a0-6cd2-11e2-bcfd-0800200c9a66" +#define ACPI_LPS0_GET_DEVICE_CONSTRAINTS 1 #define ACPI_LPS0_SCREEN_OFF 3 #define ACPI_LPS0_SCREEN_ON 4 #define ACPI_LPS0_ENTRY 5 @@ -680,6 +681,162 @@ static acpi_handle lps0_device_handle; static guid_t lps0_dsm_guid; static char lps0_dsm_func_mask; +/* Device constraint entry structure */ +struct lpi_device_info { + char *name; + int enabled; + union acpi_object *package; +}; + +/* Constraint package structure */ +struct lpi_device_constraint { + int uid; + int min_dstate; + int function_states; +}; + +struct lpi_constraints { + char *name; + int min_dstate; +}; + +static struct lpi_constraints *lpi_constraints_table; +static int lpi_constraints_table_size; + +static void lpi_device_get_constraints(void) +{ + union acpi_object *out_obj; + int i; + + out_obj = acpi_evaluate_dsm_typed(lps0_device_handle, &lps0_dsm_guid, + 1, ACPI_LPS0_GET_DEVICE_CONSTRAINTS, + NULL, ACPI_TYPE_PACKAGE); + + acpi_handle_debug(lps0_device_handle, "_DSM function 1 eval %s\n", + out_obj ? "successful" : "failed"); + + if (!out_obj) + return; + + lpi_constraints_table = kcalloc(out_obj->package.count, + sizeof(*lpi_constraints_table), + GFP_KERNEL); + if (!lpi_constraints_table) + goto free_acpi_buffer; + + pr_debug("LPI: constraints dump begin\n"); + for (i = 0; i < out_obj->package.count; i++) { + union acpi_object *package = &out_obj->package.elements[i]; + struct lpi_device_info info = { }; + int package_count = 0, j; + + if (!package) + continue; + + for (j = 0; j < package->package.count; ++j) { + union acpi_object *element = + &(package->package.elements[j]); + + switch (element->type) { + case ACPI_TYPE_INTEGER: + info.enabled = element->integer.value; + break; + case ACPI_TYPE_STRING: + info.name = element->string.pointer; + break; + case ACPI_TYPE_PACKAGE: + package_count = element->package.count; + info.package = element->package.elements; + break; + } + } + + if (!info.enabled || !info.package || !info.name) + continue; + + lpi_constraints_table[lpi_constraints_table_size].name = + kstrdup(info.name, GFP_KERNEL); + if (!lpi_constraints_table[lpi_constraints_table_size].name) + goto free_constraints; + + pr_debug("index:%d Name:%s\n", i, info.name); + + for (j = 0; j < package_count; ++j) { + union acpi_object *info_obj = &info.package[j]; + union acpi_object *cnstr_pkg; + union acpi_object *obj; + struct lpi_device_constraint dev_info; + + switch (info_obj->type) { + case ACPI_TYPE_INTEGER: + /* version */ + break; + case ACPI_TYPE_PACKAGE: + if (info_obj->package.count < 2) + break; + + cnstr_pkg = info_obj->package.elements; + obj = &cnstr_pkg[0]; + dev_info.uid = obj->integer.value; + obj = &cnstr_pkg[1]; + dev_info.min_dstate = obj->integer.value; + pr_debug("uid %d min_dstate %d\n", + dev_info.uid, + dev_info.min_dstate); + lpi_constraints_table[ + lpi_constraints_table_size].min_dstate = + dev_info.min_dstate; + break; + } + } + + lpi_constraints_table_size++; + } + + pr_debug("LPI: constraints dump end\n"); +free_acpi_buffer: + ACPI_FREE(out_obj); + return; + +free_constraints: + ACPI_FREE(out_obj); + for (i = 0; i < lpi_constraints_table_size; ++i) + kfree(lpi_constraints_table[i].name); + kfree(lpi_constraints_table); + lpi_constraints_table_size = 0; +} + +static void lpi_check_constraints(void) +{ + int i; + + for (i = 0; i < lpi_constraints_table_size; ++i) { + acpi_handle handle; + struct acpi_device *adev; + int state, ret; + + if (ACPI_FAILURE(acpi_get_handle(NULL, + lpi_constraints_table[i].name, + &handle))) + continue; + + if (acpi_bus_get_device(handle, &adev)) + continue; + + ret = acpi_device_get_power(adev, &state); + if (!ret) + pr_debug("LPI: %s required min power state %d, current power state %d, real power state %d\n", + lpi_constraints_table[i].name, + lpi_constraints_table[i].min_dstate, + adev->power.state, state); + + if (adev->flags.power_manageable && adev->power.state < + lpi_constraints_table[i].min_dstate) + pr_info("LPI: Constraint [%s] not matched\n", + lpi_constraints_table[i].name); + } +} + static void acpi_sleep_run_lps0_dsm(unsigned int func) { union acpi_object *out_obj; @@ -729,6 +886,9 @@ static int lps0_device_attach(struct acpi_device *adev, "_DSM function 0 evaluation failed\n"); } ACPI_FREE(out_obj); + + lpi_device_get_constraints(); + return 0; } @@ -773,6 +933,8 @@ static void acpi_freeze_wake(void) */ if (acpi_sci_irq_valid() && !irqd_is_wakeup_armed(irq_get_irq_data(acpi_sci_irq))) { + if (pm_debug_messages_enabled()) + lpi_check_constraints(); pm_system_cancel_wakeup(); s2idle_wakeup = true; }
For SoC to achieve its lowest power platform idle state a set of hardware preconditions must be met. These preconditions or constraints can be obtained by issuing a device specific method (_DSM) with function "1". Refer to the document provided in the link below. Here during initialization (from attach() callback of LPS0 device), invoke function 1 to get the device constraints. Each enabled constraint is stored in a table. The devices in this table are used to check whether they were in required minimum state, while entering suspend. This check is done from platform freeze wake() callback, only when /sys/power/pm_debug_messages attribute is non zero. If any constraint is not met and device is ACPI power managed then it prints the device name to kernel logs. Also if debug is enabled in acpi/sleep.c, the constraint table and state of each device on wake is dumped in kernel logs. Link: http://www.uefi.org/sites/default/files/resources/Intel_ACPI_Low_Power_S0_Idle.pdf Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> --- drivers/acpi/sleep.c | 162 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 162 insertions(+)