[PATCH usb-next v10 3/8] usb: core: add a wrapper for the USB PHYs on the HCD
Roger Quadros
rogerq at ti.com
Thu Mar 22 05:41:49 PDT 2018
On 22/03/18 10:10, Chunfeng Yun wrote:
> Hi,
> On Wed, 2018-03-21 at 13:30 +0200, Roger Quadros wrote:
>> Martin,
>>
>> On 21/03/18 00:01, Martin Blumenstingl wrote:
>>> Hi Roger, Hi Chunfeng,
>>>
>>> On Tue, Mar 20, 2018 at 1:04 PM, Chunfeng Yun <chunfeng.yun at mediatek.com> wrote:
>>>> Hi Martin & Roger:
>>>>
>>>> On Mon, 2018-03-19 at 17:12 +0100, Martin Blumenstingl wrote:
>>>>> Hi Roger,
>>>>>
>>>>> On Mon, Mar 19, 2018 at 9:49 AM, Roger Quadros <rogerq at ti.com> wrote:
>>>>>> Hi,
>>>>>>
>>>>>> On 19/03/18 00:29, Martin Blumenstingl wrote:
>>>>>>> Hi Roger,
>>>>>>>
>>>>>>> On Fri, Mar 16, 2018 at 3:32 PM, Roger Quadros <rogerq at ti.com> wrote:
>>>>>>>> +some TI folks
>>>>>>>>
>>>>>>>> Hi Martin,
>>>>>>>>
>>>>>>>> On 18/02/18 20:44, Martin Blumenstingl wrote:
>>>>>>>>> Many SoC platforms have separate devices for the USB PHY which are
>>>>>>>>> registered through the generic PHY framework. These PHYs have to be
>>>>>>>>> enabled to make the USB controller actually work. They also have to be
>>>>>>>>> disabled again on shutdown/suspend.
>>>>>>>>>
>>>>>>>>> Currently (at least) the following HCI platform drivers are using custom
>>>>>>>>> code to obtain all PHYs via devicetree for the roothub/controller and
>>>>>>>>> disable/enable them when required:
>>>>>>>>> - ehci-platform.c has ehci_platform_power_{on,off}
>>>>>>>>> - xhci-mtk.c has xhci_mtk_phy_{init,exit,power_on,power_off}
>>>>>>>>> - ohci-platform.c has ohci_platform_power_{on,off}
>>>>>>>>>
>>>>>>>>> With this new wrapper the USB PHYs can be specified directly in the
>>>>>>>>> USB controller's devicetree node (just like on the drivers listed
>>>>>>>>> above). This allows SoCs like the Amlogic Meson GXL family to operate
>>>>>>>>> correctly once this is wired up correctly. These SoCs use a dwc3
>>>>>>>>> controller and require all USB PHYs to be initialized (if one of the USB
>>>>>>>>> PHYs it not initialized then none of USB port works at all).
>>>>>>>>>
>>>>>>>>> Signed-off-by: Martin Blumenstingl <martin.blumenstingl at googlemail.com>
>>>>>>>>> Tested-by: Yixun Lan <yixun.lan at amlogic.com>
>>>>>>>>> Cc: Neil Armstrong <narmstrong at baylibre.com>
>>>>>>>>> Cc: Chunfeng Yun <chunfeng.yun at mediatek.com>
>>>>>>>>
>>>>>>>> This patch is breaking low power cases on TI SoCs when USB is in host mode.
>>>>>>>> I'll explain why below.
>>>>>>> based on your explanation and reading the TI PHY drivers I am assuming
>>>>>>> that the affected SoCs are using the "phy-omap-usb2" driver
>>>>>>>
>>>>>> yes and phy-ti-pipe3 as well i.e. "ti,phy-usb3" and "ti,omap-usb3"
>>>>> I missed that, thanks
>>>>>
>>>>>>>>> ---
>>>>>>>>> drivers/usb/core/Makefile | 2 +-
>>>>>>>>> drivers/usb/core/phy.c | 158 ++++++++++++++++++++++++++++++++++++++++++++++
>>>>>>>>> drivers/usb/core/phy.h | 7 ++
>>>>>>>>> 3 files changed, 166 insertions(+), 1 deletion(-)
>>>>>>>>> create mode 100644 drivers/usb/core/phy.c
>>>>>>>>> create mode 100644 drivers/usb/core/phy.h
>>>>>>>>>
>>>>>>>>> diff --git a/drivers/usb/core/Makefile b/drivers/usb/core/Makefile
>>>>>>>>> index 92c9cefb4317..18e874b0441e 100644
>>>>>>>>> --- a/drivers/usb/core/Makefile
>>>>>>>>> +++ b/drivers/usb/core/Makefile
>>>>>>>>> @@ -6,7 +6,7 @@
>>>>>>>>> usbcore-y := usb.o hub.o hcd.o urb.o message.o driver.o
>>>>>>>>> usbcore-y += config.o file.o buffer.o sysfs.o endpoint.o
>>>>>>>>> usbcore-y += devio.o notify.o generic.o quirks.o devices.o
>>>>>>>>> -usbcore-y += port.o
>>>>>>>>> +usbcore-y += phy.o port.o
>>>>>>>>>
>>>>>>>>> usbcore-$(CONFIG_OF) += of.o
>>>>>>>>> usbcore-$(CONFIG_USB_PCI) += hcd-pci.o
>>>>>>>>> diff --git a/drivers/usb/core/phy.c b/drivers/usb/core/phy.c
>>>>>>>>> new file mode 100644
>>>>>>>>> index 000000000000..09b7c43c0ea4
>>>>>>>>> --- /dev/null
>>>>>>>>> +++ b/drivers/usb/core/phy.c
>>>>>>>>> @@ -0,0 +1,158 @@
>>>>>>>>> +// SPDX-License-Identifier: GPL-2.0+
>>>>>>>>> +/*
>>>>>>>>> + * A wrapper for multiple PHYs which passes all phy_* function calls to
>>>>>>>>> + * multiple (actual) PHY devices. This is comes handy when initializing
>>>>>>>>> + * all PHYs on a HCD and to keep them all in the same state.
>>>>>>>>> + *
>>>>>>>>> + * Copyright (C) 2018 Martin Blumenstingl <martin.blumenstingl at googlemail.com>
>>>>>>>>> + */
>>>>>>>>> +
>>>>>>>>> +#include <linux/device.h>
>>>>>>>>> +#include <linux/list.h>
>>>>>>>>> +#include <linux/phy/phy.h>
>>>>>>>>> +#include <linux/of.h>
>>>>>>>>> +
>>>>>>>>> +#include "phy.h"
>>>>>>>>> +
>>>>>>>>> +struct usb_phy_roothub {
>>>>>>>>> + struct phy *phy;
>>>>>>>>> + struct list_head list;
>>>>>>>>> +};
>>>>>>>>> +
>>>>>>>>> +static struct usb_phy_roothub *usb_phy_roothub_alloc(struct device *dev)
>>>>>>>>> +{
>>>>>>>>> + struct usb_phy_roothub *roothub_entry;
>>>>>>>>> +
>>>>>>>>> + roothub_entry = devm_kzalloc(dev, sizeof(*roothub_entry), GFP_KERNEL);
>>>>>>>>> + if (!roothub_entry)
>>>>>>>>> + return ERR_PTR(-ENOMEM);
>>>>>>>>> +
>>>>>>>>> + INIT_LIST_HEAD(&roothub_entry->list);
>>>>>>>>> +
>>>>>>>>> + return roothub_entry;
>>>>>>>>> +}
>>>>>>>>> +
>>>>>>>>> +static int usb_phy_roothub_add_phy(struct device *dev, int index,
>>>>>>>>> + struct list_head *list)
>>>>>>>>> +{
>>>>>>>>> + struct usb_phy_roothub *roothub_entry;
>>>>>>>>> + struct phy *phy = devm_of_phy_get_by_index(dev, dev->of_node, index);
>>>>>>>>> +
>>>>>>>>> + if (IS_ERR_OR_NULL(phy)) {
>>>>>>>>> + if (!phy || PTR_ERR(phy) == -ENODEV)
>>>>>>>>> + return 0;
>>>>>>>>> + else
>>>>>>>>> + return PTR_ERR(phy);
>>>>>>>>> + }
>>>>>>>>> +
>>>>>>>>> + roothub_entry = usb_phy_roothub_alloc(dev);
>>>>>>>>> + if (IS_ERR(roothub_entry))
>>>>>>>>> + return PTR_ERR(roothub_entry);
>>>>>>>>> +
>>>>>>>>> + roothub_entry->phy = phy;
>>>>>>>>> +
>>>>>>>>> + list_add_tail(&roothub_entry->list, list);
>>>>>>>>> +
>>>>>>>>> + return 0;
>>>>>>>>> +}
>>>>>>>>> +
>>>>>>>>> +struct usb_phy_roothub *usb_phy_roothub_init(struct device *dev)
>>>>>>>>> +{
>>>>>>>>> + struct usb_phy_roothub *phy_roothub;
>>>>>>>>> + struct usb_phy_roothub *roothub_entry;
>>>>>>>>> + struct list_head *head;
>>>>>>>>> + int i, num_phys, err;
>>>>>>>>> +
>>>>>>>>> + num_phys = of_count_phandle_with_args(dev->of_node, "phys",
>>>>>>>>> + "#phy-cells");
>>>>>>>>> + if (num_phys <= 0)
>>>>>>>>> + return NULL;
>>>>>>>>> +
>>>>>>>>> + phy_roothub = usb_phy_roothub_alloc(dev);
>>>>>>>>> + if (IS_ERR(phy_roothub))
>>>>>>>>> + return phy_roothub;
>>>>>>>>> +
>>>>>>>>> + for (i = 0; i < num_phys; i++) {
>>>>>>>>> + err = usb_phy_roothub_add_phy(dev, i, &phy_roothub->list);
>>>>>>>>> + if (err)
>>>>>>>>> + goto err_out;
>>>>>>>>> + }
>>>>>>>>> +
>>>>>>>>> + head = &phy_roothub->list;
>>>>>>>>> +
>>>>>>>>> + list_for_each_entry(roothub_entry, head, list) {
>>>>>>>>> + err = phy_init(roothub_entry->phy);
>>>>>>>>
>>>>>>>> The phy_init() function actually enables the PHY clocks.
>>>>>>>> It should be moved to the usb_phy_roothub_exit() routine just before calling phy_power_on().
>>>>>>> do you mean that phy_init should be moved to usb_phy_roothub_power_on
>>>>>>> (just before phy_power_on is called within usb_phy_roothub_power_on)?
>>>>>>>
>>>>>>
>>>>>> Yes.
>>>>>>
>>>>>>> an earlier version of my patch did exactly this, but it caused
>>>>>>> problems during a suspend/resume cycle on Mediatek devices
>>>>>>> Chunfeng Yun reported that issue here [0], quote from that mail for
>>>>>>> easier reading:
>>>>>>> "In order to keep link state on mt8173, we just power off all phys(not
>>>>>>> exit) when system enter suspend, then power on them again (needn't
>>>>>>> init, otherwise device will be disconnected) when system resume, this
>>>>>>> can avoid re-enumerating device."
>>>>>>>
>>>>>>>>> + if (err)
>>>>>>>>> + goto err_exit_phys;
>>>>>>>>> + }
>>>>>>>>> +
>>>>>>>>> + return phy_roothub;
>>>>>>>>> +
>>>>>>>>> +err_exit_phys:
>>>>>>>>> + list_for_each_entry_continue_reverse(roothub_entry, head, list)
>>>>>>>>> + phy_exit(roothub_entry->phy);
>>>>>>>>> +
>>>>>>>>> +err_out:
>>>>>>>>> + return ERR_PTR(err);
>>>>>>>>> +}
>>>>>>>>> +EXPORT_SYMBOL_GPL(usb_phy_roothub_init);
>>>>>>>>> +
>>>>>>>>> +int usb_phy_roothub_exit(struct usb_phy_roothub *phy_roothub)
>>>>>>>>> +{
>>>>>>>>> + struct usb_phy_roothub *roothub_entry;
>>>>>>>>> + struct list_head *head;
>>>>>>>>> + int err, ret = 0;
>>>>>>>>> +
>>>>>>>>> + if (!phy_roothub)
>>>>>>>>> + return 0;
>>>>>>>>> +
>>>>>>>>> + head = &phy_roothub->list;
>>>>>>>>> +
>>>>>>>>> + list_for_each_entry(roothub_entry, head, list) {
>>>>>>>>> + err = phy_exit(roothub_entry->phy);
>>>>>>>>> + if (err)
>>>>>>>>> + ret = ret;
>>>>>>>>> + }
>>>>>>>>
>>>>>>>> phy_exit() should be moved to usb_phy_roothub_poweroff() just after calling phy_power_off().
>>>>>>> if I understood Chunfeng Yun correctly this will require
>>>>>>> re-enumeration of the USB devices after a suspend/resume cycle on
>>>>>>> Mediatek SoCs
>>>>>>>
>>>>>>
>>>>>> OK. I suppose that there are 2 cases
>>>>>> 1) Mediatek's case: USB controller context retained across suspend/resume.
>>>>>> Remote wakeup probably required.
>>>>>> No re-enumeration preferred after resume. phy_exit()/phy_init() must not be called
>>>>>> during suspend/resume to keep PHY link active.
>>>>> Documentation/devicetree/bindings/usb/mediatek,mtu3.txt indeed shows
>>>>> that the parent of the USB controller can be marked as "wakeup-source"
>>>>>
>>>>>> 2) TI's case: low power important: USB context is lost, OK to re-enumerate.
>>>>>> phy_exit()/phy_init() must be called during suspend/resume.
>>>>> ACK
>>>>>
>>>>>>>> With that there is nothing else being done here. Shouldn't we be doing the equivalent of
>>>>>>>> usb_phy_roothub_del_phy() and usb_phy_roothub_free() here?
>>>>>>>>
>>>>>>>>> +
>>>>>>>>> + return ret;
>>>>>>>>> +}
>>>>>>>>> +EXPORT_SYMBOL_GPL(usb_phy_roothub_exit);
>>>>>>>>> +
>>>>>>>>> +int usb_phy_roothub_power_on(struct usb_phy_roothub *phy_roothub)
>>>>>>>>> +{
>>>>>>>>> + struct usb_phy_roothub *roothub_entry;
>>>>>>>>> + struct list_head *head;
>>>>>>>>> + int err;
>>>>>>>>> +
>>>>>>>>> + if (!phy_roothub)
>>>>>>>>> + return 0;
>>>>>>>>> +
>>>>>>>>> + head = &phy_roothub->list;
>>>>>>>>> +
>>>>>>>>> + list_for_each_entry(roothub_entry, head, list) {
>>>>>>>>> + err = phy_power_on(roothub_entry->phy);
>>>>>>>>> + if (err)
>>>>>>>>> + goto err_out;
>>>>>>>>> + }
>>>>>>>>> +
>>>>>>>>> + return 0;
>>>>>>>>> +
>>>>>>>>> +err_out:
>>>>>>>>> + list_for_each_entry_continue_reverse(roothub_entry, head, list)
>>>>>>>>> + phy_power_off(roothub_entry->phy);
>>>>>>>>> +
>>>>>>>>> + return err;
>>>>>>>>> +}
>>>>>>>>> +EXPORT_SYMBOL_GPL(usb_phy_roothub_power_on);
>>>>>>>>> +
>>>>>>>>> +void usb_phy_roothub_power_off(struct usb_phy_roothub *phy_roothub)
>>>>>>>>> +{
>>>>>>>>> + struct usb_phy_roothub *roothub_entry;
>>>>>>>>> +
>>>>>>>>> + if (!phy_roothub)
>>>>>>>>> + return;
>>>>>>>>> +
>>>>>>>>> + list_for_each_entry_reverse(roothub_entry, &phy_roothub->list, list)
>>>>>>>>> + phy_power_off(roothub_entry->phy);
>>>>>>>>
>>>>>>>> Not doing the phy_exit() here leaves the clocks enabled on our SoC and
>>>>>>>> we're no longer able to reach low power states on system suspend.
>>>>>>> I'm not sure where this problem should be solved:
>>>>>>> - set skip_phy_initialization in struct usb_hcd to 1 for the affected
>>>>>>> TI platforms
>>>>>>
>>>>>> Many TI platforms are affected, omap5*, dra7*, am43*
>>>>>>
>>>>>>> - fix this in the usb_phy_roothub code
>>>>>>
>>>>>> I'd vote for fixing it in the usb_phy_roothub code. How?
>>>>>> How about using the device_can_wakeup() to decide if we should call phy_exit()/init() or not?
>>>>>> If the USB device can't wakeup the system there is no point in keeping it powered/clocked right?
>>>>> @Chunfeng: can you confirm Roger's idea that we could call phy_exit if
>>>>> the controller is *NOT* marked as "wakeup-source"?
>>>>> I am also not sure if it would work, since the "wakeup-source"
>>>>> property is defined on the USB controller's parent node in case of the
>>>>> Mediatek MTU3 (Mediatek USB3.0 DRD) controller
>>>>>
>>>> Very sorry, I forgot that MTU3 & xHCI drivers always set them as wakeup
>>>> devices by device_init_wakeup(dev, true),but not dependent on
>>>> "wakeup-source" property, so maybe we can use device_can_wakeup() to
>>>> decide whether call phy_exit()/init() or not.
>>> the 64-bit Amlogic Meson GXL/GXM SoCs don't support suspend/resume
>>> yet, so I cannot test this
>>> based on this suggestion I threw up two patches which are *compile
>>> tested only* based on Greg's usb-next branch
>>> you can find them here: [0] (as well as attached to this mail)
>>>
>>> @Chunfeng: can you please test this on one of your Mediatek SoCs?
>>> @Roger: can you please test this on a TI SoC?
>>>
>>> (apologies in advance if these patches don't work)
>>>
>>> please note that I won't have access to my computer until Saturday.
>>> if these patches need to be rewritten/replaced/etc. then feel free to
>>> send your own version to the list
>>
>> Had to do the following to build
>>
>> diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
>> index 6d4a419..2884607 100644
>> --- a/drivers/usb/core/hcd.c
>> +++ b/drivers/usb/core/hcd.c
>> @@ -2262,7 +2262,7 @@ int hcd_bus_suspend(struct usb_device *rhdev, pm_message_t msg)
>> hcd->state = HC_STATE_SUSPENDED;
>>
>> if (!PMSG_IS_AUTO(msg))
>> - usb_phy_roothub_suspend(hcd->phy_roothub);
>> + usb_phy_roothub_suspend(&rhdev->dev, hcd->phy_roothub);
>
> Try to use hcd->self.controller instead of &rhdev->dev;
Actually it should be hcd->self.sysdev.
>
>>
>> /* Did we race with a root-hub wakeup event? */
>> if (rhdev->do_remote_wakeup) {
>> @@ -2302,7 +2302,7 @@ int hcd_bus_resume(struct usb_device *rhdev, pm_message_t msg)
>> }
>>
>> if (!PMSG_IS_AUTO(msg)) {
>> - status = usb_phy_roothub_resume(hcd->phy_roothub);
>> + status = usb_phy_roothub_resume(&rhdev->dev, hcd->phy_roothub);
> ditto
>> if (status)
>> return status;
>> }
>> @@ -2344,7 +2344,7 @@ int hcd_bus_resume(struct usb_device *rhdev, pm_message_t msg)
>> }
>> } else {
>> hcd->state = old_state;
>> - usb_phy_roothub_suspend(hcd->phy_roothub);
>> + usb_phy_roothub_suspend(&rhdev->dev, hcd->phy_roothub);
> ditto
>> dev_dbg(&rhdev->dev, "bus %s fail, err %d\n",
>> "resume", status);
>> if (status != -ESHUTDOWN)
>>
>>
>> And the following to fix runtime issues
>>
>> diff --git a/drivers/usb/core/phy.c b/drivers/usb/core/phy.c
>> index 2eca371..8598906 100644
>> --- a/drivers/usb/core/phy.c
>> +++ b/drivers/usb/core/phy.c
>> @@ -32,9 +32,9 @@ static int usb_phy_roothub_add_phy(struct device *dev, int index,
>> return PTR_ERR(phy);
>> }
>>
>> - roothub_entry = usb_phy_roothub_alloc(dev);
>> - if (IS_ERR(roothub_entry))
>> - return PTR_ERR(roothub_entry);
>> + roothub_entry = devm_kzalloc(dev, sizeof(*roothub_entry), GFP_KERNEL);
>> + if (!roothub_entry)
>> + return -ENOMEM;
>>
>> roothub_entry->phy = phy;
>>
>> @@ -162,7 +162,7 @@ int usb_phy_roothub_suspend(struct device *dev,
>> usb_phy_roothub_power_off(phy_roothub);
>>
>> /* keep the PHYs initialized so the device can wake up the system */
>> - if (device_can_wakeup(dev))
>> + if (device_may_wakeup(dev))
> It's ok
I had to additionally fix usb_phy_roothub_resume() from
if (device_can_wakeup(dev))
to
if (!device_may_wakeup(dev))
>> return 0;
>>
>> return usb_phy_roothub_exit(phy_roothub);
>>
>>
>> Here are my obervations
>> - if wakeup is disabled it works fine as expected, phy_exit() is called and I'm able to reach
>> low power states.
>>
>> - if wakeup is enabled (/sys/bus/usb/device/usb2/power/wakeup), then hcd_bus_suspend() is never called
>> and so phy_power_off won't be called either.
>>
>> This means that the device_may_wakeup() check is redundant. Sorry for suggesting this.
> You maybe use a wrong device.
Yes, after using the correct device I don't see the problem.
Can you please try the below patch on top of the 2 Patches that Martin sent and the new patch you sent?
Once you confirm it works for you I can send the 2 patches officially.
diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
index 6d4a419..04cc453 100644
--- a/drivers/usb/core/hcd.c
+++ b/drivers/usb/core/hcd.c
@@ -2262,7 +2262,7 @@ int hcd_bus_suspend(struct usb_device *rhdev, pm_message_t msg)
hcd->state = HC_STATE_SUSPENDED;
if (!PMSG_IS_AUTO(msg))
- usb_phy_roothub_suspend(hcd->phy_roothub);
+ usb_phy_roothub_suspend(hcd->self.sysdev, hcd->phy_roothub);
/* Did we race with a root-hub wakeup event? */
if (rhdev->do_remote_wakeup) {
@@ -2302,7 +2302,7 @@ int hcd_bus_resume(struct usb_device *rhdev, pm_message_t msg)
}
if (!PMSG_IS_AUTO(msg)) {
- status = usb_phy_roothub_resume(hcd->phy_roothub);
+ status = usb_phy_roothub_resume(hcd->self.sysdev, hcd->phy_roothub);
if (status)
return status;
}
@@ -2344,7 +2344,7 @@ int hcd_bus_resume(struct usb_device *rhdev, pm_message_t msg)
}
} else {
hcd->state = old_state;
- usb_phy_roothub_suspend(hcd->phy_roothub);
+ usb_phy_roothub_suspend(hcd->self.sysdev, hcd->phy_roothub);
dev_dbg(&rhdev->dev, "bus %s fail, err %d\n",
"resume", status);
if (status != -ESHUTDOWN)
diff --git a/drivers/usb/core/phy.c b/drivers/usb/core/phy.c
index 2eca371..25fe729 100644
--- a/drivers/usb/core/phy.c
+++ b/drivers/usb/core/phy.c
@@ -32,9 +32,9 @@ static int usb_phy_roothub_add_phy(struct device *dev, int index,
return PTR_ERR(phy);
}
- roothub_entry = usb_phy_roothub_alloc(dev);
- if (IS_ERR(roothub_entry))
- return PTR_ERR(roothub_entry);
+ roothub_entry = devm_kzalloc(dev, sizeof(*roothub_entry), GFP_KERNEL);
+ if (!roothub_entry)
+ return -ENOMEM;
roothub_entry->phy = phy;
@@ -162,7 +162,7 @@ int usb_phy_roothub_suspend(struct device *dev,
usb_phy_roothub_power_off(phy_roothub);
/* keep the PHYs initialized so the device can wake up the system */
- if (device_can_wakeup(dev))
+ if (device_may_wakeup(dev))
return 0;
return usb_phy_roothub_exit(phy_roothub);
@@ -175,7 +175,7 @@ int usb_phy_roothub_resume(struct device *dev,
int err;
/* if the device can't wake up the system _exit was called */
- if (device_can_wakeup(dev)) {
+ if (!device_may_wakeup(dev)) {
err = usb_phy_roothub_init(phy_roothub);
if (err)
return err;
--
cheers,
-roger
Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki
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