Messages in this thread | | | Date | Wed, 17 Jul 2013 10:51:55 -0400 | From | Eduardo Valentin <> | Subject | Re: [RFC PATCH 2/4] thermal: introduce device tree parser |
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On 09-07-2013 12:14, R, Durgadoss wrote: > Hi Eduardo, > >> -----Original Message----- >> From: Eduardo Valentin [mailto:eduardo.valentin@ti.com] >> Sent: Tuesday, July 09, 2013 7:30 PM >> To: linux-pm@vger.kernel.org; R, Durgadoss; amit.daniel@samsung.com >> Cc: Zhang, Rui; Eduardo Valentin; linux-kernel@vger.kernel.org >> Subject: [RFC PATCH 2/4] thermal: introduce device tree parser >> >> In order to be able to build thermal policies >> based on generic sensors, like I2C device, that >> can be places in different points on different boards, >> there is a need to have a way to feed board dependent >> data into the thermal framework. >> >> This patch introduces a thermal data parser for device >> tree. The parsed data is used to build thermal zones >> and thermal binding parameters. The output data >> can then be used to deploy thermal policies. >> >> This patch adds also documentation regarding this >> API and how to define define tree nodes to use >> this infrastructure. >> >> Cc: Zhang Rui <rui.zhang@intel.com> >> Cc: linux-pm@vger.kernel.org >> Cc: linux-kernel@vger.kernel.org >> Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com> >> --- > > I looked at the Documentation part of this. And it looks good. > > At some places you are using ERANGE. Technically, this represents > 'Math result not representable'. May be should be use EINVAL > itself ? I would leave it up to you ;)
I will be using EDOM in next version, tks
> > Thanks, > Durga > >> .../devicetree/bindings/thermal/thermal.txt | 92 +++++ >> drivers/thermal/Kconfig | 13 + >> drivers/thermal/Makefile | 1 + >> drivers/thermal/thermal_dt.c | 412 +++++++++++++++++++++ >> drivers/thermal/thermal_dt.h | 44 +++ >> include/linux/thermal.h | 3 + >> 6 files changed, 565 insertions(+) >> create mode 100644 Documentation/devicetree/bindings/thermal/thermal.txt >> create mode 100644 drivers/thermal/thermal_dt.c >> create mode 100644 drivers/thermal/thermal_dt.h >> >> diff --git a/Documentation/devicetree/bindings/thermal/thermal.txt >> b/Documentation/devicetree/bindings/thermal/thermal.txt >> new file mode 100644 >> index 0000000..2c25ab2 >> --- /dev/null >> +++ b/Documentation/devicetree/bindings/thermal/thermal.txt >> @@ -0,0 +1,92 @@ >> +---------------------------------------- >> +Thermal Framework Device Tree descriptor >> +---------------------------------------- >> + >> +This file describes how to define a thermal structure using device tree. >> +A thermal structure includes thermal zones and their components, such >> +as name, governor, trip points, polling intervals and cooling devices >> +binding descriptors. A binding descriptor may contain information on >> +how to react, with a cooling stepped action or a weight on a fair share. >> + >> +**** >> +trip >> +**** >> + >> +The trip node is a node to describe a point in the temperature domain >> +in which the system takes an action. This node describes just the point, >> +not the action. >> + >> +A node describing a trip must contain: >> +- temperature: the trip temperature level, in milliCelsius. >> +- hysteresis: a (low) hysteresis value on 'temperature'. This is a relative >> +value, in milliCelsius. >> +- type: the trip type. Here is the type mapping: >> + THERMAL_TRIP_ACTIVE = 0 >> + THERMAL_TRIP_PASSIVE = 1 >> + THERMAL_TRIP_HOT = 2 >> + THERMAL_TRIP_CRITICAL = 3 >> + >> +********** >> +bind_param >> +********** >> + >> +The bind_param node is a node to describe how cooling devices get assigned >> +to trip points of the zone. The cooling devices are expected to be loaded >> +in the target system. >> + >> +A node describing a bind_param must contain: >> +- cooling_device: A string with the cooling device name. >> +- weight: The 'influence' of a particular cooling device on this zone. >> + This is on a percentage scale. The sum of all these weights >> + (for a particular zone) cannot exceed 100. >> +- trip_mask: This is a bit mask that gives the binding relation between >> + this thermal zone and cdev, for a particular trip point. >> + If nth bit is set, then the cdev and thermal zone are bound >> + for trip point n. >> + >> +************ >> +thermal_zone >> +************ >> + >> +The thermal_zone node is the node containing all the required info >> +for describing a thermal zone, including its cdev bindings. The thermal_zone >> +node must contain, apart from its own properties, one node containing >> +trip nodes and one node containing all the zone bind parameters. >> + >> +Required properties: >> +- type: this is a string containing the zone type. Say 'cpu', 'core', 'mem', etc. >> +- mask: Bit string: If 'n'th bit is set, then trip point 'n' is writeable. >> + >> +- passive_delay: number of milliseconds to wait between polls when >> + performing passive cooling. >> +- polling_delay: number of milliseconds to wait between polls when checking >> + >> +- governor: A string containing the default governor for this zone. >> + >> +Below is an example: >> +thermal_zone { >> + type = "CPU"; >> + mask = <0x03>; /* trips writability */ >> + passive_delay = <250>; /* milliseconds */ >> + polling_delay = <1000>; /* milliseconds */ >> + governor = "step_wise"; >> + trips { >> + alert@100000{ >> + temperature = <100000>; /* milliCelsius */ >> + hysteresis = <0>; /* milliCelsius */ >> + type = <1>; >> + }; >> + crit@125000{ >> + temperature = <125000>; /* milliCelsius */ >> + hysteresis = <0>; /* milliCelsius */ >> + type = <3>; >> + }; >> + }; >> + bind_params { >> + action@0{ >> + cooling_device = "thermal-cpufreq"; >> + weight = <100>; /* percentage */ >> + mask = <0x01>; >> + }; >> + }; >> +}; >> diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig >> index 7fb16bc..753f0dc 100644 >> --- a/drivers/thermal/Kconfig >> +++ b/drivers/thermal/Kconfig >> @@ -29,6 +29,19 @@ config THERMAL_HWMON >> Say 'Y' here if you want all thermal sensors to >> have hwmon sysfs interface too. >> >> +config THERMAL_OF >> + bool >> + prompt "APIs to parse thermal data out of device tree" >> + depends on OF >> + default y >> + help >> + This options provides helpers to add the support to >> + read and parse thermal data definitions out of the >> + device tree blob. >> + >> + Say 'Y' here if you need to build thermal infrastructure >> + based on device tree. >> + >> choice >> prompt "Default Thermal governor" >> default THERMAL_DEFAULT_GOV_STEP_WISE >> diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile >> index 24cb894..eedb273 100644 >> --- a/drivers/thermal/Makefile >> +++ b/drivers/thermal/Makefile >> @@ -7,6 +7,7 @@ thermal_sys-y += thermal_core.o >> >> # interface to/from other layers providing sensors >> thermal_sys-$(CONFIG_THERMAL_HWMON) += thermal_hwmon.o >> +thermal_sys-$(CONFIG_THERMAL_OF) += thermal_dt.o >> >> # governors >> thermal_sys-$(CONFIG_THERMAL_GOV_FAIR_SHARE) += fair_share.o >> diff --git a/drivers/thermal/thermal_dt.c b/drivers/thermal/thermal_dt.c >> new file mode 100644 >> index 0000000..6553582 >> --- /dev/null >> +++ b/drivers/thermal/thermal_dt.c >> @@ -0,0 +1,412 @@ >> +/* >> + * thermal_dt.c - Generic Thermal Management device tree support. >> + * >> + * Copyright (C) 2013 Texas Instruments >> + * Copyright (C) 2013 Eduardo Valentin <eduardo.valentin@ti.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. >> + * >> + * This program is distributed in the hope that it will be useful, but >> + * WITHOUT ANY WARRANTY; without even the implied warranty of >> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU >> + * General Public License for more details. >> + * >> + * You should have received a copy of the GNU General Public License along >> + * with this program; if not, write to the Free Software Foundation, Inc., >> + * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. >> + * >> + * >> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ >> ~~~~~~~~~~~~ >> + */ >> +#include <linux/thermal.h> >> +#include <linux/slab.h> >> +#include <linux/of_device.h> >> +#include <linux/of_platform.h> >> +#include <linux/err.h> >> +#include <linux/export.h> >> +#include <linux/string.h> >> + >> +struct __thermal_bind_params { >> + char cooling_device[THERMAL_NAME_LENGTH]; >> +}; >> + >> +static >> +int thermal_of_match(struct thermal_zone_device *tz, >> + struct thermal_cooling_device *cdev); >> + >> +static int thermal_of_populate_bind_params(struct device *dev, >> + struct device_node *node, >> + struct __thermal_bind_params *__tbp, >> + struct thermal_bind_params *tbp) >> +{ >> + const char *cdev_name; >> + int ret; >> + u32 prop; >> + >> + ret = of_property_read_u32(node, "weight", &prop); >> + if (ret < 0) { >> + dev_err(dev, "missing weight property\n"); >> + return ret; >> + } >> + tbp->weight = prop; >> + >> + ret = of_property_read_u32(node, "mask", &prop); >> + if (ret < 0) { >> + dev_err(dev, "missing mask property\n"); >> + return ret; >> + } >> + tbp->trip_mask = prop; >> + >> + /* this will allow us to bind with cooling devices */ >> + tbp->match = thermal_of_match; >> + >> + ret = of_property_read_string(node, "cooling_device", &cdev_name); >> + if (ret < 0) { >> + dev_err(dev, "missing cooling_device property\n"); >> + return ret; >> + } >> + strncpy(__tbp->cooling_device, cdev_name, >> + sizeof(__tbp->cooling_device)); >> + >> + return 0; >> +} >> + >> +struct __thermal_trip { >> + unsigned long int temperature; >> + unsigned long int hysteresis; >> + enum thermal_trip_type type; >> +}; >> + >> +static >> +int thermal_of_populate_trip(struct device *dev, >> + struct device_node *node, >> + struct __thermal_trip *trip) >> +{ >> + int ret; >> + int prop; >> + >> + ret = of_property_read_u32(node, "temperature", &prop); >> + if (ret < 0) { >> + dev_err(dev, "missing temperature property\n"); >> + return ret; >> + } >> + trip->temperature = prop; >> + >> + ret = of_property_read_u32(node, "hysteresis", &prop); >> + if (ret < 0) { >> + dev_err(dev, "missing hysteresis property\n"); >> + return ret; >> + } >> + trip->hysteresis = prop; >> + >> + ret = of_property_read_u32(node, "type", &prop); >> + if (ret < 0) { >> + dev_err(dev, "missing type property\n"); >> + return ret; >> + } >> + trip->type = prop; >> + >> + return 0; >> +} >> + >> +struct __thermal_zone_device { >> + enum thermal_device_mode mode; >> + int passive_delay; >> + int polling_delay; >> + int mask; >> + int ntrips; >> + char type[THERMAL_NAME_LENGTH]; >> + struct __thermal_trip *trips; >> + struct __thermal_bind_params *bind_params; >> + struct thermal_bind_params *tbps; >> + struct thermal_zone_params zone_params; >> + int (*get_temp)(void *, unsigned long *); >> + void *devdata; >> +}; >> + >> +static >> +struct __thermal_zone_device *thermal_of_build_thermal_zone(struct device >> *dev) >> +{ >> + struct device_node *child, *gchild, *node; >> + struct __thermal_zone_device *tz; >> + const char *name; >> + int ret, i; >> + u32 prop; >> + >> + node = dev->of_node; >> + if (!node) >> + return ERR_PTR(-EINVAL); >> + >> + node = of_find_node_by_name(node, "thermal_zone"); >> + if (!node) { >> + dev_err(dev, "no thermal_zone node found\n"); >> + return ERR_PTR(-EINVAL); >> + } >> + >> + tz = devm_kzalloc(dev, sizeof(*tz), GFP_KERNEL); >> + if (!tz) { >> + dev_err(dev, "not enough memory for thermal of zone\n"); >> + return ERR_PTR(-ENOMEM); >> + } >> + >> + ret = of_property_read_u32(node, "passive_delay", &prop); >> + if (ret < 0) { >> + dev_err(dev, "missing passive_delay property\n"); >> + return ERR_PTR(ret); >> + } >> + tz->passive_delay = prop; >> + >> + ret = of_property_read_u32(node, "polling_delay", &prop); >> + if (ret < 0) { >> + dev_err(dev, "missing polling_delay property\n"); >> + return ERR_PTR(ret); >> + } >> + tz->polling_delay = prop; >> + >> + ret = of_property_read_u32(node, "mask", &prop); >> + if (ret < 0) { >> + dev_err(dev, "missing mask property\n"); >> + return ERR_PTR(ret); >> + } >> + tz->mask = prop; >> + >> + ret = of_property_read_string(node, "type", &name); >> + if (ret < 0) { >> + dev_err(dev, "missing type property\n"); >> + return ERR_PTR(ret); >> + } >> + strncpy(tz->type, name, sizeof(tz->type)); >> + >> + ret = of_property_read_string(node, "governor", &name); >> + if (ret < 0) { >> + dev_err(dev, "missing governor property\n"); >> + return ERR_PTR(ret); >> + } >> + strncpy(tz->zone_params.governor_name, name, >> + sizeof(tz->zone_params.governor_name)); >> + >> + /* trips */ >> + child = of_find_node_by_name(node, "trips"); >> + tz->ntrips = of_get_child_count(child); >> + tz->trips = devm_kzalloc(dev, tz->ntrips * sizeof(*tz->trips), >> + GFP_KERNEL); >> + if (!tz->trips) >> + return ERR_PTR(-ENOMEM); >> + i = 0; >> + for_each_child_of_node(child, gchild) >> + thermal_of_populate_trip(dev, gchild, &tz->trips[i++]); >> + >> + /* bind_params */ >> + child = of_find_node_by_name(node, "bind_params"); >> + tz->zone_params.num_tbps = of_get_child_count(child); >> + tz->bind_params = devm_kzalloc(dev, >> + tz->zone_params.num_tbps * >> + sizeof(*tz->bind_params), >> + GFP_KERNEL); >> + if (!tz->bind_params) >> + return ERR_PTR(-ENOMEM); >> + tz->zone_params.tbp = devm_kzalloc(dev, >> + tz->zone_params.num_tbps * >> + sizeof(*tz->zone_params.tbp), >> + GFP_KERNEL); >> + if (!tz->zone_params.tbp) >> + return ERR_PTR(-ENOMEM); >> + i = 0; >> + for_each_child_of_node(child, gchild) { >> + thermal_of_populate_bind_params(dev, gchild, >> + &tz->bind_params[i], >> + &tz->zone_params.tbp[i]); >> + i++; >> + } >> + tz->mode = THERMAL_DEVICE_ENABLED; >> + >> + return tz; >> +} >> + >> +static >> +int thermal_of_match(struct thermal_zone_device *tz, >> + struct thermal_cooling_device *cdev) >> +{ >> + struct __thermal_zone_device *data = tz->devdata; >> + int i; >> + >> + for (i = 0; i < data->zone_params.num_tbps; i++) { >> + if (!strncmp(data->bind_params[i].cooling_device, >> + cdev->type, >> + strlen(data->bind_params[i].cooling_device)) && >> + (data->zone_params.tbp[i].trip_mask & (1 << i))) >> + return 0; >> + } >> + >> + return -EINVAL; >> +} >> + >> +static >> +int of_thermal_get_temp(struct thermal_zone_device *tz, >> + unsigned long *temp) >> +{ >> + struct __thermal_zone_device *data = tz->devdata; >> + >> + return data->get_temp(data->devdata, temp); >> +} >> + >> +static >> +int of_thermal_get_mode(struct thermal_zone_device *tz, >> + enum thermal_device_mode *mode) >> +{ >> + struct __thermal_zone_device *data = tz->devdata; >> + >> + *mode = data->mode; >> + >> + return 0; >> +} >> + >> +static >> +int of_thermal_set_mode(struct thermal_zone_device *tz, >> + enum thermal_device_mode mode) >> +{ >> + struct __thermal_zone_device *data = tz->devdata; >> + >> + mutex_lock(&tz->lock); >> + >> + if (mode == THERMAL_DEVICE_ENABLED) >> + tz->polling_delay = data->polling_delay; >> + else >> + tz->polling_delay = 0; >> + >> + mutex_unlock(&tz->lock); >> + >> + data->mode = mode; >> + thermal_zone_device_update(tz); >> + >> + return 0; >> +} >> + >> +static >> +int of_thermal_get_trip_type(struct thermal_zone_device *tz, int trip, >> + enum thermal_trip_type *type) >> +{ >> + struct __thermal_zone_device *data = tz->devdata; >> + >> + if (trip >= data->ntrips || trip < 0) >> + return -ERANGE; >> + >> + *type = data->trips[trip].type; >> + >> + return 0; >> +} >> + >> +static >> +int of_thermal_get_trip_temp(struct thermal_zone_device *tz, int trip, >> + unsigned long *temp) >> +{ >> + struct __thermal_zone_device *data = tz->devdata; >> + >> + if (trip >= data->ntrips || trip < 0) >> + return -ERANGE; >> + >> + *temp = data->trips[trip].temperature; >> + >> + return 0; >> +} >> + >> +static >> +int of_thermal_set_trip_temp(struct thermal_zone_device *tz, int trip, >> + unsigned long temp) >> +{ >> + struct __thermal_zone_device *data = tz->devdata; >> + >> + if (trip >= data->ntrips || trip < 0) >> + return -ERANGE; >> + >> + /* thermal fw should take care of data->mask & (1 << trip) */ >> + data->trips[trip].temperature = temp; >> + >> + return 0; >> +} >> + >> +static >> +int of_thermal_get_trip_hyst(struct thermal_zone_device *tz, int trip, >> + unsigned long *hyst) >> +{ >> + struct __thermal_zone_device *data = tz->devdata; >> + >> + if (trip >= data->ntrips || trip < 0) >> + return -ERANGE; >> + >> + *hyst = data->trips[trip].hysteresis; >> + >> + return 0; >> +} >> + >> +static >> +int of_thermal_set_trip_hyst(struct thermal_zone_device *tz, int trip, >> + unsigned long hyst) >> +{ >> + struct __thermal_zone_device *data = tz->devdata; >> + >> + if (trip >= data->ntrips || trip < 0) >> + return -ERANGE; >> + >> + /* thermal fw should take care of data->mask & (1 << trip) */ >> + data->trips[trip].hysteresis = hyst; >> + >> + return 0; >> +} >> + >> +static int >> +of_thermal_get_crit_temp(struct thermal_zone_device *tz, unsigned long >> *temp) >> +{ >> + struct __thermal_zone_device *data = tz->devdata; >> + int i; >> + >> + for (i = 0; i < data->ntrips; i++) >> + if (data->trips[i].type == THERMAL_TRIP_CRITICAL) { >> + *temp = data->trips[i].temperature; >> + return 0; >> + } >> + >> + return -EINVAL; >> +} >> + >> +static const >> +struct thermal_zone_device_ops of_thermal_ops = { >> + .get_temp = of_thermal_get_temp, >> + .get_mode = of_thermal_get_mode, >> + .set_mode = of_thermal_set_mode, >> + .get_trip_type = of_thermal_get_trip_type, >> + .get_trip_temp = of_thermal_get_trip_temp, >> + .set_trip_temp = of_thermal_set_trip_temp, >> + .get_trip_hyst = of_thermal_get_trip_hyst, >> + .set_trip_hyst = of_thermal_set_trip_hyst, >> + .get_crit_temp = of_thermal_get_crit_temp, >> +}; >> + >> +struct thermal_zone_device *thermal_zone_of_device_register(struct device >> *dev, >> + void *data, int (*get_temp)(void *, unsigned long *)) >> +{ >> + struct __thermal_zone_device *tz; >> + struct thermal_zone_device_ops *ops; >> + >> + tz = thermal_of_build_thermal_zone(dev); >> + if (IS_ERR(tz)) { >> + dev_err(dev, "failed to build thermal zone\n"); >> + return NULL; >> + } >> + ops = devm_kzalloc(dev, sizeof(*ops), GFP_KERNEL); >> + if (!ops) { >> + dev_err(dev, "no memory available for thermal ops\n"); >> + return NULL; >> + } >> + memcpy(ops, &of_thermal_ops, sizeof(*ops)); >> + tz->get_temp = get_temp; >> + tz->devdata = data; >> + >> + return thermal_zone_device_register(tz->type, tz->ntrips, tz->mask, tz, >> + ops, &tz->zone_params, >> + tz->passive_delay, >> + tz->polling_delay); >> +} >> +EXPORT_SYMBOL_GPL(thermal_zone_of_device_register); >> diff --git a/drivers/thermal/thermal_dt.h b/drivers/thermal/thermal_dt.h >> new file mode 100644 >> index 0000000..5491d19 >> --- /dev/null >> +++ b/drivers/thermal/thermal_dt.h >> @@ -0,0 +1,44 @@ >> +/* >> + * thermal_dt.h - Generic Thermal Management device tree support. >> + * >> + * Copyright (C) 2013 Texas Instruments >> + * Copyright (C) 2013 Eduardo Valentin <eduardo.valentin@ti.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. >> + * >> + * This program is distributed in the hope that it will be useful, but >> + * WITHOUT ANY WARRANTY; without even the implied warranty of >> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU >> + * General Public License for more details. >> + * >> + * You should have received a copy of the GNU General Public License along >> + * with this program; if not, write to the Free Software Foundation, Inc., >> + * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. >> + * >> + * >> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ >> ~~~~~~~~~~~~ >> + */ >> +#ifndef __THERMAL_DT_H__ >> +#define __THERMAL_DT_H__ >> +#include <linux/device.h> >> + >> +#ifdef CONFIG_THERMAL_OF >> +struct thermal_bind_params *thermal_of_build_bind_params(struct device >> *dev); >> +struct thermal_zone_device *thermal_of_build_thermal_zone(struct device >> *dev); >> +#else >> +static >> +struct thermal_bind_params *thermal_of_build_bind_params(struct device >> *dev) >> +{ >> + return NULL; >> +} >> + >> +static >> +struct thermal_zone_device *thermal_of_build_thermal_zone(struct device >> *dev) >> +{ >> + return NULL; >> +} >> +#endif >> + >> +#endif /* __THERMAL_DT_H__ */ >> diff --git a/include/linux/thermal.h b/include/linux/thermal.h >> index a386a1c..a62ada0 100644 >> --- a/include/linux/thermal.h >> +++ b/include/linux/thermal.h >> @@ -224,6 +224,9 @@ struct thermal_genl_event { >> }; >> >> /* Function declarations */ >> +struct thermal_zone_device >> +*thermal_zone_of_device_register(struct device *, void *data, >> + int (*get_temp) (void *, unsigned long *)); >> struct thermal_zone_device *thermal_zone_device_register(const char *, int, >> int, >> void *, const struct thermal_zone_device_ops *, >> const struct thermal_zone_params *, int, int); >> -- >> 1.8.2.1.342.gfa7285d > > >
-- You have got to be excited about what you are doing. (L. Lamport)
Eduardo Valentin
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