> -----Original Message----- > From: Srinivas Pandruvada [mailto:srinivas.pandruvada@xxxxxxxxxxxxxxx] > Sent: Tuesday, August 8, 2017 5:41 PM > To: rjw@xxxxxxxxxxxxx; lenb@xxxxxxxxxx > Cc: linux-pm@xxxxxxxxxxxxxxx; Limonciello, Mario <Mario_Limonciello@xxxxxxxx>; > linux-kernel@xxxxxxxxxxxxxxx; linux-acpi@xxxxxxxxxxxxxxx; lukas@xxxxxxxxx; > Srinivas Pandruvada <srinivas.pandruvada@xxxxxxxxxxxxxxx> > 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@xxxxxxxxxxxxxxx> > --- > 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 -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
