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* [PATCH v2] usb: core: reduce power-on-good delay time of root hub
@ 2021-04-10  1:20 Chunfeng Yun
  2021-11-01  3:33 ` Walt Jr. Brake
       [not found] ` <5e907ccd-40bb-2ece-fe05-1a65a74f3aa2@gmail.com>
  0 siblings, 2 replies; 15+ messages in thread
From: Chunfeng Yun @ 2021-04-10  1:20 UTC (permalink / raw)
  To: Greg Kroah-Hartman, Alan Stern
  Cc: Matthias Brugger, Chunfeng Yun, Nishad Kamdar, linux-usb,
	linux-kernel, linux-arm-kernel, linux-mediatek, Eddie Hung

Return the exactly delay time given by root hub descriptor,
this helps to reduce resume time etc.

Due to the root hub descriptor is usually provided by the host
controller driver, if there is compatibility for a root hub,
we can fix it easily without affect other root hub

Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
---
v2: remove RFC tag, and add acked-by Alan
---
 drivers/usb/core/hub.h | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/core/hub.h b/drivers/usb/core/hub.h
index 73f4482d833a..22ea1f4f2d66 100644
--- a/drivers/usb/core/hub.h
+++ b/drivers/usb/core/hub.h
@@ -148,8 +148,10 @@ static inline unsigned hub_power_on_good_delay(struct usb_hub *hub)
 {
 	unsigned delay = hub->descriptor->bPwrOn2PwrGood * 2;
 
-	/* Wait at least 100 msec for power to become stable */
-	return max(delay, 100U);
+	if (!hub->hdev->parent)	/* root hub */
+		return delay;
+	else /* Wait at least 100 msec for power to become stable */
+		return max(delay, 100U);
 }
 
 static inline int hub_port_debounce_be_connected(struct usb_hub *hub,
-- 
2.18.0


^ permalink raw reply	[flat|nested] 15+ messages in thread

* Re: [PATCH v2] usb: core: reduce power-on-good delay time of root hub
  2021-04-10  1:20 [PATCH v2] usb: core: reduce power-on-good delay time of root hub Chunfeng Yun
@ 2021-11-01  3:33 ` Walt Jr. Brake
       [not found] ` <5e907ccd-40bb-2ece-fe05-1a65a74f3aa2@gmail.com>
  1 sibling, 0 replies; 15+ messages in thread
From: Walt Jr. Brake @ 2021-11-01  3:33 UTC (permalink / raw)
  To: chunfeng.yun
  Cc: eddie.hung, gregkh, linux-arm-kernel, linux-kernel,
	linux-mediatek, linux-usb, matthias.bgg, nishadkamdar, stern

Three month ago, My USB 3.1 device cannot be detected after upgrade 
kernel from version 5.10.41 to 5.10.42.

And I found some other people ran into the same issue:

https://forum.manjaro.org/t/kernel-5-10-59-doesnt-detect-a-connected-usb-external-disk/79320

https://forum.manjaro.org/t/how-to-make-active-usb-hub-work-in-manjaro/84548

Two days ago, I try to fix the issue myself, and I found out that it was 
cause by this patch. After revert this patch, my USB 3.1 device can be 
detect again.

I have already file a bug on here: 
https://bugzilla.kernel.org/show_bug.cgi?id=214875.



^ permalink raw reply	[flat|nested] 15+ messages in thread

* Re: [PATCH v2] usb: core: reduce power-on-good delay time of root hub
       [not found] ` <5e907ccd-40bb-2ece-fe05-1a65a74f3aa2@gmail.com>
@ 2021-11-01 14:06   ` Alan Stern
  2021-11-02  9:05     ` Mathias Nyman
  0 siblings, 1 reply; 15+ messages in thread
From: Alan Stern @ 2021-11-01 14:06 UTC (permalink / raw)
  To: Mathias Nyman, Walt Jr. Brake
  Cc: Chunfeng Yun, Greg Kroah-Hartman, Matthias Brugger,
	Nishad Kamdar, linux-usb, linux-kernel, linux-arm-kernel,
	linux-mediatek, Eddie Hung

On Sat, Oct 30, 2021 at 12:49:37PM +0800, Walt Jr. Brake wrote:
> This patch make USB 3.1 device cannot be detected, and I report the bug [1]
> to archlinux three month ago. Yesterday I try to fix it myself, and after I
> revert this patch, compile the kernel and test, it works.
> 
> [1] https://bugs.archlinux.org/task/71660?project=1&pagenum=2
> 
> 
> diff --git a/drivers/usb/core/hub.h b/drivers/usb/core/hub.h
> index 22ea1f4f2d66..73f4482d833a 100644
> --- a/drivers/usb/core/hub.h
> +++ b/drivers/usb/core/hub.h
> @@ -148,10 +148,8 @@ static inline unsigned hub_power_on_good_delay(struct
> usb_hub *hub)
>  {
>         unsigned delay = hub->descriptor->bPwrOn2PwrGood * 2;
> 
> -       if (!hub->hdev->parent) /* root hub */
> -               return delay;
> -       else /* Wait at least 100 msec for power to become stable */
> -               return max(delay, 100U);
> +       /* Wait at least 100 msec for power to become stable */
> +       return max(delay, 100U);
>  }

Mathias:

It looks like the bPwrOn2PwrGood value in xhci-hcd's hub descriptor is 
too small for some USB 3.1 devices.

Can you look into this?

Alan Stern

> On 10/4/2021 09:20, Chunfeng Yun wrote:
> > Return the exactly delay time given by root hub descriptor,
> > this helps to reduce resume time etc.
> > 
> > Due to the root hub descriptor is usually provided by the host
> > controller driver, if there is compatibility for a root hub,
> > we can fix it easily without affect other root hub
> > 
> > Acked-by: Alan Stern<stern@rowland.harvard.edu>
> > Signed-off-by: Chunfeng Yun<chunfeng.yun@mediatek.com>
> > ---
> > v2: remove RFC tag, and add acked-by Alan
> > ---
> >   drivers/usb/core/hub.h | 6 ++++--
> >   1 file changed, 4 insertions(+), 2 deletions(-)
> > 
> > diff --git a/drivers/usb/core/hub.h b/drivers/usb/core/hub.h
> > index 73f4482d833a..22ea1f4f2d66 100644
> > --- a/drivers/usb/core/hub.h
> > +++ b/drivers/usb/core/hub.h
> > @@ -148,8 +148,10 @@ static inline unsigned hub_power_on_good_delay(struct usb_hub *hub)
> >   {
> >   	unsigned delay = hub->descriptor->bPwrOn2PwrGood * 2;
> > -	/* Wait at least 100 msec for power to become stable */
> > -	return max(delay, 100U);
> > +	if (!hub->hdev->parent)	/* root hub */
> > +		return delay;
> > +	else /* Wait at least 100 msec for power to become stable */
> > +		return max(delay, 100U);
> >   }
> >   static inline int hub_port_debounce_be_connected(struct usb_hub *hub,

^ permalink raw reply	[flat|nested] 15+ messages in thread

* Re: [PATCH v2] usb: core: reduce power-on-good delay time of root hub
  2021-11-01 14:06   ` Alan Stern
@ 2021-11-02  9:05     ` Mathias Nyman
  2021-11-02 20:29       ` Walt Jr. Brake
  0 siblings, 1 reply; 15+ messages in thread
From: Mathias Nyman @ 2021-11-02  9:05 UTC (permalink / raw)
  To: Alan Stern, Mathias Nyman, Walt Jr. Brake
  Cc: Chunfeng Yun, Greg Kroah-Hartman, Matthias Brugger,
	Nishad Kamdar, linux-usb, linux-kernel, linux-arm-kernel,
	linux-mediatek, Eddie Hung

On 1.11.2021 16.06, Alan Stern wrote:
> On Sat, Oct 30, 2021 at 12:49:37PM +0800, Walt Jr. Brake wrote:
>> This patch make USB 3.1 device cannot be detected, and I report the bug [1]
>> to archlinux three month ago. Yesterday I try to fix it myself, and after I
>> revert this patch, compile the kernel and test, it works.
>>
>> [1] https://bugs.archlinux.org/task/71660?project=1&pagenum=2
>>
>>
>> diff --git a/drivers/usb/core/hub.h b/drivers/usb/core/hub.h
>> index 22ea1f4f2d66..73f4482d833a 100644
>> --- a/drivers/usb/core/hub.h
>> +++ b/drivers/usb/core/hub.h
>> @@ -148,10 +148,8 @@ static inline unsigned hub_power_on_good_delay(struct
>> usb_hub *hub)
>>  {
>>         unsigned delay = hub->descriptor->bPwrOn2PwrGood * 2;
>>
>> -       if (!hub->hdev->parent) /* root hub */
>> -               return delay;
>> -       else /* Wait at least 100 msec for power to become stable */
>> -               return max(delay, 100U);
>> +       /* Wait at least 100 msec for power to become stable */
>> +       return max(delay, 100U);
>>  }
> 
> Mathias:
> 
> It looks like the bPwrOn2PwrGood value in xhci-hcd's hub descriptor is 
> too small for some USB 3.1 devices.
> 
> Can you look into this?
> 
> Alan Stern
> 

At first glance the xhci roothub bPwrOn2PwrGood value looks ok.
xhci spec 5.4.8 states software should wait 20ms after asserting PP, before
attempting to change the state of the port.

xhci driver sets desc->bPwrOn2PwrGood = 10; (2ms interval, so equals 20ms )

We should probably get this working immediately, so maybe revert that patch
while looking into the rootcause.

Walt Jr. Brake, instead of reverting that patch, could you test if changing the
xhci roothub bPwrOn2PwrGood value helps.

diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c
index a3f875eea751..756231a55602 100644
--- a/drivers/usb/host/xhci-hub.c
+++ b/drivers/usb/host/xhci-hub.c
@@ -257,7 +257,7 @@ static void xhci_common_hub_descriptor(struct xhci_hcd *xhci,
 {
        u16 temp;
 
-       desc->bPwrOn2PwrGood = 10;      /* xhci section 5.4.9 says 20ms max */
+       desc->bPwrOn2PwrGood = 50;      /* The 20ms in xhci 5.4.8 isn't enough for USB 3.1 */
        desc->bHubContrCurrent = 0;
 
        desc->bNbrPorts = ports;

Thanks
-Mathias

^ permalink raw reply	[flat|nested] 15+ messages in thread

* Re: [PATCH v2] usb: core: reduce power-on-good delay time of root hub
  2021-11-02  9:05     ` Mathias Nyman
@ 2021-11-02 20:29       ` Walt Jr. Brake
  2021-11-03 20:37         ` Mathias Nyman
  0 siblings, 1 reply; 15+ messages in thread
From: Walt Jr. Brake @ 2021-11-02 20:29 UTC (permalink / raw)
  To: Mathias Nyman, Alan Stern, Mathias Nyman
  Cc: Chunfeng Yun, Greg Kroah-Hartman, Matthias Brugger,
	Nishad Kamdar, linux-usb, linux-kernel, linux-arm-kernel,
	linux-mediatek, Eddie Hung

On 2/11/2021 17:05, Mathias Nyman wrote:
> On 1.11.2021 16.06, Alan Stern wrote:
>> On Sat, Oct 30, 2021 at 12:49:37PM +0800, Walt Jr. Brake wrote:
>>> This patch make USB 3.1 device cannot be detected, and I report the bug [1]
>>> to archlinux three month ago. Yesterday I try to fix it myself, and after I
>>> revert this patch, compile the kernel and test, it works.
>>>
>>> [1] https://bugs.archlinux.org/task/71660?project=1&pagenum=2
>>>
>>>
>>> diff --git a/drivers/usb/core/hub.h b/drivers/usb/core/hub.h
>>> index 22ea1f4f2d66..73f4482d833a 100644
>>> --- a/drivers/usb/core/hub.h
>>> +++ b/drivers/usb/core/hub.h
>>> @@ -148,10 +148,8 @@ static inline unsigned hub_power_on_good_delay(struct
>>> usb_hub *hub)
>>>   {
>>>          unsigned delay = hub->descriptor->bPwrOn2PwrGood * 2;
>>>
>>> -       if (!hub->hdev->parent) /* root hub */
>>> -               return delay;
>>> -       else /* Wait at least 100 msec for power to become stable */
>>> -               return max(delay, 100U);
>>> +       /* Wait at least 100 msec for power to become stable */
>>> +       return max(delay, 100U);
>>>   }
>> Mathias:
>>
>> It looks like the bPwrOn2PwrGood value in xhci-hcd's hub descriptor is
>> too small for some USB 3.1 devices.
>>
>> Can you look into this?
>>
>> Alan Stern
>>
> At first glance the xhci roothub bPwrOn2PwrGood value looks ok.
> xhci spec 5.4.8 states software should wait 20ms after asserting PP, before
> attempting to change the state of the port.
>
> xhci driver sets desc->bPwrOn2PwrGood = 10; (2ms interval, so equals 20ms )
>
> We should probably get this working immediately, so maybe revert that patch
> while looking into the rootcause.
>
> Walt Jr. Brake, instead of reverting that patch, could you test if changing the
> xhci roothub bPwrOn2PwrGood value helps.
>
> diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c
> index a3f875eea751..756231a55602 100644
> --- a/drivers/usb/host/xhci-hub.c
> +++ b/drivers/usb/host/xhci-hub.c
> @@ -257,7 +257,7 @@ static void xhci_common_hub_descriptor(struct xhci_hcd *xhci,
>   {
>          u16 temp;
>   
> -       desc->bPwrOn2PwrGood = 10;      /* xhci section 5.4.9 says 20ms max */
> +       desc->bPwrOn2PwrGood = 50;      /* The 20ms in xhci 5.4.8 isn't enough for USB 3.1 */
>          desc->bHubContrCurrent = 0;
>   
>          desc->bNbrPorts = ports;
>
> Thanks
> -Mathias

Mathias:

Sorry to reply lately. I test with your patch, it works.

I also test with setting bPwrOn2PwrGood to 45, and it not work.

Seems that the minimal value should be 50 for this case.


^ permalink raw reply	[flat|nested] 15+ messages in thread

* Re: [PATCH v2] usb: core: reduce power-on-good delay time of root hub
  2021-11-02 20:29       ` Walt Jr. Brake
@ 2021-11-03 20:37         ` Mathias Nyman
  2021-11-05 10:00           ` Greg Kroah-Hartman
  0 siblings, 1 reply; 15+ messages in thread
From: Mathias Nyman @ 2021-11-03 20:37 UTC (permalink / raw)
  To: Walt Jr. Brake, Alan Stern, Mathias Nyman
  Cc: Chunfeng Yun, Greg Kroah-Hartman, Matthias Brugger,
	Nishad Kamdar, linux-usb, linux-kernel, linux-arm-kernel,
	linux-mediatek, Eddie Hung

On 2.11.2021 22.29, Walt Jr. Brake wrote:
> On 2/11/2021 17:05, Mathias Nyman wrote:
>> On 1.11.2021 16.06, Alan Stern wrote:
>>> On Sat, Oct 30, 2021 at 12:49:37PM +0800, Walt Jr. Brake wrote:
>>>> This patch make USB 3.1 device cannot be detected, and I report the bug [1]
>>>> to archlinux three month ago. Yesterday I try to fix it myself, and after I
>>>> revert this patch, compile the kernel and test, it works.
>>>>
>>>> [1] https://bugs.archlinux.org/task/71660?project=1&pagenum=2
>>>>
>>>>
>>>> diff --git a/drivers/usb/core/hub.h b/drivers/usb/core/hub.h
>>>> index 22ea1f4f2d66..73f4482d833a 100644
>>>> --- a/drivers/usb/core/hub.h
>>>> +++ b/drivers/usb/core/hub.h
>>>> @@ -148,10 +148,8 @@ static inline unsigned hub_power_on_good_delay(struct
>>>> usb_hub *hub)
>>>>   {
>>>>          unsigned delay = hub->descriptor->bPwrOn2PwrGood * 2;
>>>>
>>>> -       if (!hub->hdev->parent) /* root hub */
>>>> -               return delay;
>>>> -       else /* Wait at least 100 msec for power to become stable */
>>>> -               return max(delay, 100U);
>>>> +       /* Wait at least 100 msec for power to become stable */
>>>> +       return max(delay, 100U);
>>>>   }
>>> Mathias:
>>>
>>> It looks like the bPwrOn2PwrGood value in xhci-hcd's hub descriptor is
>>> too small for some USB 3.1 devices.
>>>
>>> Can you look into this?
>>>
>>> Alan Stern
>>>
>> At first glance the xhci roothub bPwrOn2PwrGood value looks ok.
>> xhci spec 5.4.8 states software should wait 20ms after asserting PP, before
>> attempting to change the state of the port.
>>
>> xhci driver sets desc->bPwrOn2PwrGood = 10; (2ms interval, so equals 20ms )
>>
>> We should probably get this working immediately, so maybe revert that patch
>> while looking into the rootcause.
>>
>> Walt Jr. Brake, instead of reverting that patch, could you test if changing the
>> xhci roothub bPwrOn2PwrGood value helps.
>>
>> diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c
>> index a3f875eea751..756231a55602 100644
>> --- a/drivers/usb/host/xhci-hub.c
>> +++ b/drivers/usb/host/xhci-hub.c
>> @@ -257,7 +257,7 @@ static void xhci_common_hub_descriptor(struct xhci_hcd *xhci,
>>   {
>>          u16 temp;
>>   -       desc->bPwrOn2PwrGood = 10;      /* xhci section 5.4.9 says 20ms max */
>> +       desc->bPwrOn2PwrGood = 50;      /* The 20ms in xhci 5.4.8 isn't enough for USB 3.1 */
>>          desc->bHubContrCurrent = 0;
>>            desc->bNbrPorts = ports;
>>
>> Thanks
>> -Mathias
> 
> Mathias:
> 
> Sorry to reply lately. I test with your patch, it works.
> 
> I also test with setting bPwrOn2PwrGood to 45, and it not work.
> 
> Seems that the minimal value should be 50 for this case.
> 

Thanks for testing, and for checking that 90ms wait isn't enough

-Mathias

^ permalink raw reply	[flat|nested] 15+ messages in thread

* Re: [PATCH v2] usb: core: reduce power-on-good delay time of root hub
  2021-11-03 20:37         ` Mathias Nyman
@ 2021-11-05 10:00           ` Greg Kroah-Hartman
  2021-11-05 13:30             ` Alan Stern
  0 siblings, 1 reply; 15+ messages in thread
From: Greg Kroah-Hartman @ 2021-11-05 10:00 UTC (permalink / raw)
  To: Mathias Nyman
  Cc: Walt Jr. Brake, Alan Stern, Mathias Nyman, Chunfeng Yun,
	Matthias Brugger, Nishad Kamdar, linux-usb, linux-kernel,
	linux-arm-kernel, linux-mediatek, Eddie Hung

On Wed, Nov 03, 2021 at 10:37:33PM +0200, Mathias Nyman wrote:
> On 2.11.2021 22.29, Walt Jr. Brake wrote:
> > On 2/11/2021 17:05, Mathias Nyman wrote:
> >> On 1.11.2021 16.06, Alan Stern wrote:
> >>> On Sat, Oct 30, 2021 at 12:49:37PM +0800, Walt Jr. Brake wrote:
> >>>> This patch make USB 3.1 device cannot be detected, and I report the bug [1]
> >>>> to archlinux three month ago. Yesterday I try to fix it myself, and after I
> >>>> revert this patch, compile the kernel and test, it works.
> >>>>
> >>>> [1] https://bugs.archlinux.org/task/71660?project=1&pagenum=2
> >>>>
> >>>>
> >>>> diff --git a/drivers/usb/core/hub.h b/drivers/usb/core/hub.h
> >>>> index 22ea1f4f2d66..73f4482d833a 100644
> >>>> --- a/drivers/usb/core/hub.h
> >>>> +++ b/drivers/usb/core/hub.h
> >>>> @@ -148,10 +148,8 @@ static inline unsigned hub_power_on_good_delay(struct
> >>>> usb_hub *hub)
> >>>>   {
> >>>>          unsigned delay = hub->descriptor->bPwrOn2PwrGood * 2;
> >>>>
> >>>> -       if (!hub->hdev->parent) /* root hub */
> >>>> -               return delay;
> >>>> -       else /* Wait at least 100 msec for power to become stable */
> >>>> -               return max(delay, 100U);
> >>>> +       /* Wait at least 100 msec for power to become stable */
> >>>> +       return max(delay, 100U);
> >>>>   }
> >>> Mathias:
> >>>
> >>> It looks like the bPwrOn2PwrGood value in xhci-hcd's hub descriptor is
> >>> too small for some USB 3.1 devices.
> >>>
> >>> Can you look into this?
> >>>
> >>> Alan Stern
> >>>
> >> At first glance the xhci roothub bPwrOn2PwrGood value looks ok.
> >> xhci spec 5.4.8 states software should wait 20ms after asserting PP, before
> >> attempting to change the state of the port.
> >>
> >> xhci driver sets desc->bPwrOn2PwrGood = 10; (2ms interval, so equals 20ms )
> >>
> >> We should probably get this working immediately, so maybe revert that patch
> >> while looking into the rootcause.
> >>
> >> Walt Jr. Brake, instead of reverting that patch, could you test if changing the
> >> xhci roothub bPwrOn2PwrGood value helps.
> >>
> >> diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c
> >> index a3f875eea751..756231a55602 100644
> >> --- a/drivers/usb/host/xhci-hub.c
> >> +++ b/drivers/usb/host/xhci-hub.c
> >> @@ -257,7 +257,7 @@ static void xhci_common_hub_descriptor(struct xhci_hcd *xhci,
> >>   {
> >>          u16 temp;
> >>   -       desc->bPwrOn2PwrGood = 10;      /* xhci section 5.4.9 says 20ms max */
> >> +       desc->bPwrOn2PwrGood = 50;      /* The 20ms in xhci 5.4.8 isn't enough for USB 3.1 */
> >>          desc->bHubContrCurrent = 0;
> >>            desc->bNbrPorts = ports;
> >>
> >> Thanks
> >> -Mathias
> > 
> > Mathias:
> > 
> > Sorry to reply lately. I test with your patch, it works.
> > 
> > I also test with setting bPwrOn2PwrGood to 45, and it not work.
> > 
> > Seems that the minimal value should be 50 for this case.
> > 
> 
> Thanks for testing, and for checking that 90ms wait isn't enough

Can you send a "real" patch for this so I can get it into the tree soon
to resolve the regression?

thanks,

greg k-h

^ permalink raw reply	[flat|nested] 15+ messages in thread

* Re: [PATCH v2] usb: core: reduce power-on-good delay time of root hub
  2021-11-05 10:00           ` Greg Kroah-Hartman
@ 2021-11-05 13:30             ` Alan Stern
  2021-11-05 16:00               ` [PATCH] xhci: Fix USB 3.1 enumeration issues by increasing roothub power-on-good delay Mathias Nyman
  0 siblings, 1 reply; 15+ messages in thread
From: Alan Stern @ 2021-11-05 13:30 UTC (permalink / raw)
  To: Greg Kroah-Hartman
  Cc: Mathias Nyman, Walt Jr. Brake, Mathias Nyman, Chunfeng Yun,
	Matthias Brugger, Nishad Kamdar, linux-usb, linux-kernel,
	linux-arm-kernel, linux-mediatek, Eddie Hung

On Fri, Nov 05, 2021 at 11:00:31AM +0100, Greg Kroah-Hartman wrote:
> On Wed, Nov 03, 2021 at 10:37:33PM +0200, Mathias Nyman wrote:
> > On 2.11.2021 22.29, Walt Jr. Brake wrote:
> > > On 2/11/2021 17:05, Mathias Nyman wrote:
> > >> On 1.11.2021 16.06, Alan Stern wrote:
> > >>> On Sat, Oct 30, 2021 at 12:49:37PM +0800, Walt Jr. Brake wrote:
> > >>>> This patch make USB 3.1 device cannot be detected, and I report the bug [1]
> > >>>> to archlinux three month ago. Yesterday I try to fix it myself, and after I
> > >>>> revert this patch, compile the kernel and test, it works.
> > >>>>
> > >>>> [1] https://bugs.archlinux.org/task/71660?project=1&pagenum=2
> > >>>>
> > >>>>
> > >>>> diff --git a/drivers/usb/core/hub.h b/drivers/usb/core/hub.h
> > >>>> index 22ea1f4f2d66..73f4482d833a 100644
> > >>>> --- a/drivers/usb/core/hub.h
> > >>>> +++ b/drivers/usb/core/hub.h
> > >>>> @@ -148,10 +148,8 @@ static inline unsigned hub_power_on_good_delay(struct
> > >>>> usb_hub *hub)
> > >>>>   {
> > >>>>          unsigned delay = hub->descriptor->bPwrOn2PwrGood * 2;
> > >>>>
> > >>>> -       if (!hub->hdev->parent) /* root hub */
> > >>>> -               return delay;
> > >>>> -       else /* Wait at least 100 msec for power to become stable */
> > >>>> -               return max(delay, 100U);
> > >>>> +       /* Wait at least 100 msec for power to become stable */
> > >>>> +       return max(delay, 100U);
> > >>>>   }
> > >>> Mathias:
> > >>>
> > >>> It looks like the bPwrOn2PwrGood value in xhci-hcd's hub descriptor is
> > >>> too small for some USB 3.1 devices.
> > >>>
> > >>> Can you look into this?
> > >>>
> > >>> Alan Stern
> > >>>
> > >> At first glance the xhci roothub bPwrOn2PwrGood value looks ok.
> > >> xhci spec 5.4.8 states software should wait 20ms after asserting PP, before
> > >> attempting to change the state of the port.
> > >>
> > >> xhci driver sets desc->bPwrOn2PwrGood = 10; (2ms interval, so equals 20ms )
> > >>
> > >> We should probably get this working immediately, so maybe revert that patch
> > >> while looking into the rootcause.
> > >>
> > >> Walt Jr. Brake, instead of reverting that patch, could you test if changing the
> > >> xhci roothub bPwrOn2PwrGood value helps.
> > >>
> > >> diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c
> > >> index a3f875eea751..756231a55602 100644
> > >> --- a/drivers/usb/host/xhci-hub.c
> > >> +++ b/drivers/usb/host/xhci-hub.c
> > >> @@ -257,7 +257,7 @@ static void xhci_common_hub_descriptor(struct xhci_hcd *xhci,
> > >>   {
> > >>          u16 temp;
> > >>   -       desc->bPwrOn2PwrGood = 10;      /* xhci section 5.4.9 says 20ms max */
> > >> +       desc->bPwrOn2PwrGood = 50;      /* The 20ms in xhci 5.4.8 isn't enough for USB 3.1 */
> > >>          desc->bHubContrCurrent = 0;
> > >>            desc->bNbrPorts = ports;
> > >>
> > >> Thanks
> > >> -Mathias
> > > 
> > > Mathias:
> > > 
> > > Sorry to reply lately. I test with your patch, it works.
> > > 
> > > I also test with setting bPwrOn2PwrGood to 45, and it not work.
> > > 
> > > Seems that the minimal value should be 50 for this case.
> > > 
> > 
> > Thanks for testing, and for checking that 90ms wait isn't enough
> 
> Can you send a "real" patch for this so I can get it into the tree soon
> to resolve the regression?

Also, it might make sense to move the desc->bPwrOn2PwrGood setting from 
xhci_common_hub_descriptor into the speed-specific routines.  For the 
USB-2 root hub the value can remain set to 10; only the USB-3 root hub 
needs to be changed.

Alan Stern

^ permalink raw reply	[flat|nested] 15+ messages in thread

* [PATCH] xhci: Fix USB 3.1 enumeration issues by increasing roothub power-on-good delay
  2021-11-05 13:30             ` Alan Stern
@ 2021-11-05 16:00               ` Mathias Nyman
  2021-11-05 16:09                 ` Mathias Nyman
  2021-11-05 16:15                 ` Greg KH
  0 siblings, 2 replies; 15+ messages in thread
From: Mathias Nyman @ 2021-11-05 16:00 UTC (permalink / raw)
  To: stern, gregkh
  Cc: mr.yming81, chunfeng.yun, matthias.bgg, nishadkamdar, linux-usb,
	linux-kernel, linux-arm-kernel, linux-mediatek, eddie.hung,
	Mathias Nyman

Some USB 3.1 enumeration issues were reported after the hub driver removed
the minimum 100ms limit for the power-on-good delay.

Since commit 90d28fb53d4a ("usb: core: reduce power-on-good delay time of
root hub") the hub driver sets the power-on-delay based on the
bPwrOn2PwrGood value in the hub descriptor.

xhci driver has a 20ms bPwrOn2PwrGood value for both roothubs based
on xhci spec section 5.4.8, but it's clearly not enough for the
USB 3.1 devices, causing enumeration issues.

Tests indicate full 100ms delay is needed.

Reported-by: Walt Jr. Brake <mr.yming81@gmail.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
---
 drivers/usb/host/xhci-hub.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c
index a3f875eea751..af946c42b6f0 100644
--- a/drivers/usb/host/xhci-hub.c
+++ b/drivers/usb/host/xhci-hub.c
@@ -257,7 +257,6 @@ static void xhci_common_hub_descriptor(struct xhci_hcd *xhci,
 {
 	u16 temp;
 
-	desc->bPwrOn2PwrGood = 10;	/* xhci section 5.4.9 says 20ms max */
 	desc->bHubContrCurrent = 0;
 
 	desc->bNbrPorts = ports;
@@ -292,6 +291,7 @@ static void xhci_usb2_hub_descriptor(struct usb_hcd *hcd, struct xhci_hcd *xhci,
 	desc->bDescriptorType = USB_DT_HUB;
 	temp = 1 + (ports / 8);
 	desc->bDescLength = USB_DT_HUB_NONVAR_SIZE + 2 * temp;
+	desc->bPwrOn2PwrGood = 10;	/* xhci section 5.4.8 says 20ms */
 
 	/* The Device Removable bits are reported on a byte granularity.
 	 * If the port doesn't exist within that byte, the bit is set to 0.
@@ -344,6 +344,7 @@ static void xhci_usb3_hub_descriptor(struct usb_hcd *hcd, struct xhci_hcd *xhci,
 	xhci_common_hub_descriptor(xhci, desc, ports);
 	desc->bDescriptorType = USB_DT_SS_HUB;
 	desc->bDescLength = USB_DT_SS_HUB_SIZE;
+	desc->bPwrOn2PwrGood = 50;	/* usb 3.1 may fail if less than 100ms */
 
 	/* header decode latency should be zero for roothubs,
 	 * see section 4.23.5.2.
-- 
2.25.1


^ permalink raw reply	[flat|nested] 15+ messages in thread

* Re: [PATCH] xhci: Fix USB 3.1 enumeration issues by increasing roothub power-on-good delay
  2021-11-05 16:00               ` [PATCH] xhci: Fix USB 3.1 enumeration issues by increasing roothub power-on-good delay Mathias Nyman
@ 2021-11-05 16:09                 ` Mathias Nyman
  2021-11-05 17:32                   ` Walt Jr. Brake
  2021-11-05 16:15                 ` Greg KH
  1 sibling, 1 reply; 15+ messages in thread
From: Mathias Nyman @ 2021-11-05 16:09 UTC (permalink / raw)
  To: Walt Jr. Brake
  Cc: chunfeng.yun, matthias.bgg, nishadkamdar, linux-usb,
	linux-kernel, linux-arm-kernel, linux-mediatek, eddie.hung,
	Alan Stern, Greg KH

On 5.11.2021 18.00, Mathias Nyman wrote:
> Some USB 3.1 enumeration issues were reported after the hub driver removed
> the minimum 100ms limit for the power-on-good delay.
> 
> Since commit 90d28fb53d4a ("usb: core: reduce power-on-good delay time of
> root hub") the hub driver sets the power-on-delay based on the
> bPwrOn2PwrGood value in the hub descriptor.
> 
> xhci driver has a 20ms bPwrOn2PwrGood value for both roothubs based
> on xhci spec section 5.4.8, but it's clearly not enough for the
> USB 3.1 devices, causing enumeration issues.
> 
> Tests indicate full 100ms delay is needed.
> 
> Reported-by: Walt Jr. Brake <mr.yming81@gmail.com>
> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
> 

Walt Jr Brake, just to be sure could you test this one as well?

As Alan suggested this sets 100ms for the USB 3 roothub but
keeps the 20ms for the USB 2 roothub.

Thanks
-Mathias 

^ permalink raw reply	[flat|nested] 15+ messages in thread

* Re: [PATCH] xhci: Fix USB 3.1 enumeration issues by increasing roothub power-on-good delay
  2021-11-05 16:00               ` [PATCH] xhci: Fix USB 3.1 enumeration issues by increasing roothub power-on-good delay Mathias Nyman
  2021-11-05 16:09                 ` Mathias Nyman
@ 2021-11-05 16:15                 ` Greg KH
  2021-11-05 19:56                   ` Mathias Nyman
  1 sibling, 1 reply; 15+ messages in thread
From: Greg KH @ 2021-11-05 16:15 UTC (permalink / raw)
  To: Mathias Nyman
  Cc: stern, mr.yming81, chunfeng.yun, matthias.bgg, nishadkamdar,
	linux-usb, linux-kernel, linux-arm-kernel, linux-mediatek,
	eddie.hung

On Fri, Nov 05, 2021 at 06:00:36PM +0200, Mathias Nyman wrote:
> Some USB 3.1 enumeration issues were reported after the hub driver removed
> the minimum 100ms limit for the power-on-good delay.
> 
> Since commit 90d28fb53d4a ("usb: core: reduce power-on-good delay time of
> root hub") the hub driver sets the power-on-delay based on the
> bPwrOn2PwrGood value in the hub descriptor.
> 
> xhci driver has a 20ms bPwrOn2PwrGood value for both roothubs based
> on xhci spec section 5.4.8, but it's clearly not enough for the
> USB 3.1 devices, causing enumeration issues.
> 
> Tests indicate full 100ms delay is needed.
> 
> Reported-by: Walt Jr. Brake <mr.yming81@gmail.com>
> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>

So this needs:
	Fixes: 90d28fb53d4a ("usb: core: reduce power-on-good delay time of root hub")
right?

thanks,

greg k-h

^ permalink raw reply	[flat|nested] 15+ messages in thread

* Re: [PATCH] xhci: Fix USB 3.1 enumeration issues by increasing roothub power-on-good delay
  2021-11-05 16:09                 ` Mathias Nyman
@ 2021-11-05 17:32                   ` Walt Jr. Brake
  2021-11-05 19:41                     ` Mathias Nyman
  0 siblings, 1 reply; 15+ messages in thread
From: Walt Jr. Brake @ 2021-11-05 17:32 UTC (permalink / raw)
  To: Mathias Nyman
  Cc: chunfeng.yun, matthias.bgg, nishadkamdar, linux-usb,
	linux-kernel, linux-arm-kernel, linux-mediatek, eddie.hung,
	Alan Stern, Greg KH

On 6/11/2021 00:09, Mathias Nyman wrote:
> On 5.11.2021 18.00, Mathias Nyman wrote:
>> Some USB 3.1 enumeration issues were reported after the hub driver removed
>> the minimum 100ms limit for the power-on-good delay.
>>
>> Since commit 90d28fb53d4a ("usb: core: reduce power-on-good delay time of
>> root hub") the hub driver sets the power-on-delay based on the
>> bPwrOn2PwrGood value in the hub descriptor.
>>
>> xhci driver has a 20ms bPwrOn2PwrGood value for both roothubs based
>> on xhci spec section 5.4.8, but it's clearly not enough for the
>> USB 3.1 devices, causing enumeration issues.
>>
>> Tests indicate full 100ms delay is needed.
>>
>> Reported-by: Walt Jr. Brake <mr.yming81@gmail.com>
>> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
>>
> Walt Jr Brake, just to be sure could you test this one as well?
>
> As Alan suggested this sets 100ms for the USB 3 roothub but
> keeps the 20ms for the USB 2 roothub.
>
> Thanks
> -Mathias

Yes I tested, it works too.


^ permalink raw reply	[flat|nested] 15+ messages in thread

* Re: [PATCH] xhci: Fix USB 3.1 enumeration issues by increasing roothub power-on-good delay
  2021-11-05 17:32                   ` Walt Jr. Brake
@ 2021-11-05 19:41                     ` Mathias Nyman
  0 siblings, 0 replies; 15+ messages in thread
From: Mathias Nyman @ 2021-11-05 19:41 UTC (permalink / raw)
  To: Walt Jr. Brake
  Cc: chunfeng.yun, matthias.bgg, nishadkamdar, linux-usb,
	linux-kernel, linux-arm-kernel, linux-mediatek, eddie.hung,
	Alan Stern, Greg KH

On 5.11.2021 19.32, Walt Jr. Brake wrote:
> On 6/11/2021 00:09, Mathias Nyman wrote:
>> On 5.11.2021 18.00, Mathias Nyman wrote:
>>> Some USB 3.1 enumeration issues were reported after the hub driver removed
>>> the minimum 100ms limit for the power-on-good delay.
>>>
>>> Since commit 90d28fb53d4a ("usb: core: reduce power-on-good delay time of
>>> root hub") the hub driver sets the power-on-delay based on the
>>> bPwrOn2PwrGood value in the hub descriptor.
>>>
>>> xhci driver has a 20ms bPwrOn2PwrGood value for both roothubs based
>>> on xhci spec section 5.4.8, but it's clearly not enough for the
>>> USB 3.1 devices, causing enumeration issues.
>>>
>>> Tests indicate full 100ms delay is needed.
>>>
>>> Reported-by: Walt Jr. Brake <mr.yming81@gmail.com>
>>> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
>>>
>> Walt Jr Brake, just to be sure could you test this one as well?
>>
>> As Alan suggested this sets 100ms for the USB 3 roothub but
>> keeps the 20ms for the USB 2 roothub.
>>
>> Thanks
>> -Mathias
> 
> Yes I tested, it works too.
> 

Thank you
-Mathias

^ permalink raw reply	[flat|nested] 15+ messages in thread

* Re: [PATCH] xhci: Fix USB 3.1 enumeration issues by increasing roothub power-on-good delay
  2021-11-05 16:15                 ` Greg KH
@ 2021-11-05 19:56                   ` Mathias Nyman
  2021-11-06 14:41                     ` Greg KH
  0 siblings, 1 reply; 15+ messages in thread
From: Mathias Nyman @ 2021-11-05 19:56 UTC (permalink / raw)
  To: Greg KH
  Cc: stern, mr.yming81, chunfeng.yun, matthias.bgg, nishadkamdar,
	linux-usb, linux-kernel, linux-arm-kernel, linux-mediatek,
	eddie.hung

On 5.11.2021 18.15, Greg KH wrote:
> On Fri, Nov 05, 2021 at 06:00:36PM +0200, Mathias Nyman wrote:
>> Some USB 3.1 enumeration issues were reported after the hub driver removed
>> the minimum 100ms limit for the power-on-good delay.
>>
>> Since commit 90d28fb53d4a ("usb: core: reduce power-on-good delay time of
>> root hub") the hub driver sets the power-on-delay based on the
>> bPwrOn2PwrGood value in the hub descriptor.
>>
>> xhci driver has a 20ms bPwrOn2PwrGood value for both roothubs based
>> on xhci spec section 5.4.8, but it's clearly not enough for the
>> USB 3.1 devices, causing enumeration issues.
>>
>> Tests indicate full 100ms delay is needed.
>>
>> Reported-by: Walt Jr. Brake <mr.yming81@gmail.com>
>> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
> 
> So this needs:
> 	Fixes: 90d28fb53d4a ("usb: core: reduce power-on-good delay time of root hub")
> right?

I guess so, not sure on "Fixes" policy here.

This patch fixes an xhci issue revealed by ("usb: core: reduce power-on-good delay time of root hub")
That original patch itself looks correct, but these two patches should really go together to
avoid any enumeration issues.  

Thanks
-Mathias

^ permalink raw reply	[flat|nested] 15+ messages in thread

* Re: [PATCH] xhci: Fix USB 3.1 enumeration issues by increasing roothub power-on-good delay
  2021-11-05 19:56                   ` Mathias Nyman
@ 2021-11-06 14:41                     ` Greg KH
  0 siblings, 0 replies; 15+ messages in thread
From: Greg KH @ 2021-11-06 14:41 UTC (permalink / raw)
  To: Mathias Nyman
  Cc: stern, mr.yming81, chunfeng.yun, matthias.bgg, nishadkamdar,
	linux-usb, linux-kernel, linux-arm-kernel, linux-mediatek,
	eddie.hung

On Fri, Nov 05, 2021 at 09:56:59PM +0200, Mathias Nyman wrote:
> On 5.11.2021 18.15, Greg KH wrote:
> > On Fri, Nov 05, 2021 at 06:00:36PM +0200, Mathias Nyman wrote:
> >> Some USB 3.1 enumeration issues were reported after the hub driver removed
> >> the minimum 100ms limit for the power-on-good delay.
> >>
> >> Since commit 90d28fb53d4a ("usb: core: reduce power-on-good delay time of
> >> root hub") the hub driver sets the power-on-delay based on the
> >> bPwrOn2PwrGood value in the hub descriptor.
> >>
> >> xhci driver has a 20ms bPwrOn2PwrGood value for both roothubs based
> >> on xhci spec section 5.4.8, but it's clearly not enough for the
> >> USB 3.1 devices, causing enumeration issues.
> >>
> >> Tests indicate full 100ms delay is needed.
> >>
> >> Reported-by: Walt Jr. Brake <mr.yming81@gmail.com>
> >> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
> > 
> > So this needs:
> > 	Fixes: 90d28fb53d4a ("usb: core: reduce power-on-good delay time of root hub")
> > right?
> 
> I guess so, not sure on "Fixes" policy here.
> 
> This patch fixes an xhci issue revealed by ("usb: core: reduce power-on-good delay time of root hub")
> That original patch itself looks correct, but these two patches should really go together to
> avoid any enumeration issues.  

Great, I'll use that tag for now so that it will get backported
properly.

greg k-h

^ permalink raw reply	[flat|nested] 15+ messages in thread

end of thread, other threads:[~2021-11-06 14:41 UTC | newest]

Thread overview: 15+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-04-10  1:20 [PATCH v2] usb: core: reduce power-on-good delay time of root hub Chunfeng Yun
2021-11-01  3:33 ` Walt Jr. Brake
     [not found] ` <5e907ccd-40bb-2ece-fe05-1a65a74f3aa2@gmail.com>
2021-11-01 14:06   ` Alan Stern
2021-11-02  9:05     ` Mathias Nyman
2021-11-02 20:29       ` Walt Jr. Brake
2021-11-03 20:37         ` Mathias Nyman
2021-11-05 10:00           ` Greg Kroah-Hartman
2021-11-05 13:30             ` Alan Stern
2021-11-05 16:00               ` [PATCH] xhci: Fix USB 3.1 enumeration issues by increasing roothub power-on-good delay Mathias Nyman
2021-11-05 16:09                 ` Mathias Nyman
2021-11-05 17:32                   ` Walt Jr. Brake
2021-11-05 19:41                     ` Mathias Nyman
2021-11-05 16:15                 ` Greg KH
2021-11-05 19:56                   ` Mathias Nyman
2021-11-06 14:41                     ` Greg KH

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