[PATCH] usb: hcd: initialize hcd->flags to 0 when rm hcd

[PATCH] usb: hcd: initialize hcd->flags to 0 when rm hcd

[William Wu]

From: William wu <wulf@rock-chips.com>

On some platforms(e.g. rk3399 board), we can call hcd_add/remove
consecutively without calling usb_put_hcd/usb_create_hcd in between,
so hcd->flags can be stale.

If the HC dies due to whatever reason then without this patch we get
the below error on next hcd_add.

[173.296154] xhci-hcd xhci-hcd.2.auto: HC died; cleaning up
[173.296209] xhci-hcd xhci-hcd.2.auto: xHCI Host Controller
[173.296762] xhci-hcd xhci-hcd.2.auto: new USB bus registered, assigned bus number 6
[173.296931] usb usb6: We don't know the algorithms for LPM for this host, disabling LPM.
[173.297179] usb usb6: New USB device found, idVendor=1d6b, idProduct=0003
[173.297203] usb usb6: New USB device strings: Mfr=3, Product=2, SerialNumber=1
[173.297222] usb usb6: Product: xHCI Host Controller
[173.297240] usb usb6: Manufacturer: Linux 4.4.21 xhci-hcd
[173.297257] usb usb6: SerialNumber: xhci-hcd.2.auto
[173.298680] hub 6-0:1.0: USB hub found
[173.298749] hub 6-0:1.0: 1 port detected
[173.299382] rockchip-dwc3 usb@fe800000: USB HOST connected
[173.395418] hub 5-0:1.0: activate --> -19
[173.603447] irq 228: nobody cared (try booting with the "irqpoll" option)
[173.603493] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.4.21 #9
[173.603513] Hardware name: Google Kevin (DT)
[173.603531] Call trace:
[173.603568] [<ffffffc0002087dc>] dump_backtrace+0x0/0x160
[173.603596] [<ffffffc00020895c>] show_stack+0x20/0x28
[173.603623] [<ffffffc0004b28a8>] dump_stack+0x90/0xb0
[173.603650] [<ffffffc00027347c>] __report_bad_irq+0x48/0xe8
[173.603674] [<ffffffc0002737cc>] note_interrupt+0x1e8/0x28c
[173.603698] [<ffffffc000270a38>] handle_irq_event_percpu+0x1d4/0x25c
[173.603722] [<ffffffc000270b0c>] handle_irq_event+0x4c/0x7c
[173.603748] [<ffffffc00027456c>] handle_fasteoi_irq+0xb4/0x124
[173.603777] [<ffffffc00026fe3c>] generic_handle_irq+0x30/0x44
[173.603804] [<ffffffc0002701a8>] __handle_domain_irq+0x90/0xbc
[173.603827] [<ffffffc0002006f4>] gic_handle_irq+0xcc/0x188
...
[173.604500] [<ffffffc000203700>] el1_irq+0x80/0xf8
[173.604530] [<ffffffc000261388>] cpu_startup_entry+0x38/0x3cc
[173.604558] [<ffffffc00090f7d8>] rest_init+0x8c/0x94
[173.604585] [<ffffffc000e009ac>] start_kernel+0x3d0/0x3fc
[173.604607] [<0000000000b16000>] 0xb16000
[173.604622] handlers:
[173.604648] [<ffffffc000642084>] usb_hcd_irq
[173.604673] Disabling IRQ #228

Signed-off-by: William wu <wulf@rock-chips.com>
Signed-off-by: William wu <william.wu@rock-chips.com>
---
 drivers/usb/core/hcd.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
index 479e223..612fab6 100644
--- a/drivers/usb/core/hcd.c
+++ b/drivers/usb/core/hcd.c
@@ -3017,6 +3017,7 @@ void usb_remove_hcd(struct usb_hcd *hcd)
 	}
 
 	usb_put_invalidate_rhdev(hcd);
+	hcd->flags = 0;
 }
 EXPORT_SYMBOL_GPL(usb_remove_hcd);
 
-- 
2.7.4

Re: [PATCH] usb: hcd: initialize hcd->flags to 0 when rm hcd

[Roger Quadros]

William,

On 12/01/17 14:03, William Wu wrote:
> From: William wu <wulf-TNX95d0MmH7DzftRWevZcw@public.gmane.org>
> 
> On some platforms(e.g. rk3399 board), we can call hcd_add/remove
> consecutively without calling usb_put_hcd/usb_create_hcd in between,
> so hcd->flags can be stale.
> 
> If the HC dies due to whatever reason then without this patch we get
> the below error on next hcd_add.
> 
> [173.296154] xhci-hcd xhci-hcd.2.auto: HC died; cleaning up
> [173.296209] xhci-hcd xhci-hcd.2.auto: xHCI Host Controller
> [173.296762] xhci-hcd xhci-hcd.2.auto: new USB bus registered, assigned bus number 6
> [173.296931] usb usb6: We don't know the algorithms for LPM for this host, disabling LPM.
> [173.297179] usb usb6: New USB device found, idVendor=1d6b, idProduct=0003
> [173.297203] usb usb6: New USB device strings: Mfr=3, Product=2, SerialNumber=1
> [173.297222] usb usb6: Product: xHCI Host Controller
> [173.297240] usb usb6: Manufacturer: Linux 4.4.21 xhci-hcd
> [173.297257] usb usb6: SerialNumber: xhci-hcd.2.auto
> [173.298680] hub 6-0:1.0: USB hub found
> [173.298749] hub 6-0:1.0: 1 port detected
> [173.299382] rockchip-dwc3 usb@fe800000: USB HOST connected
> [173.395418] hub 5-0:1.0: activate --> -19
> [173.603447] irq 228: nobody cared (try booting with the "irqpoll" option)
> [173.603493] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.4.21 #9
> [173.603513] Hardware name: Google Kevin (DT)
> [173.603531] Call trace:
> [173.603568] [<ffffffc0002087dc>] dump_backtrace+0x0/0x160
> [173.603596] [<ffffffc00020895c>] show_stack+0x20/0x28
> [173.603623] [<ffffffc0004b28a8>] dump_stack+0x90/0xb0
> [173.603650] [<ffffffc00027347c>] __report_bad_irq+0x48/0xe8
> [173.603674] [<ffffffc0002737cc>] note_interrupt+0x1e8/0x28c
> [173.603698] [<ffffffc000270a38>] handle_irq_event_percpu+0x1d4/0x25c
> [173.603722] [<ffffffc000270b0c>] handle_irq_event+0x4c/0x7c
> [173.603748] [<ffffffc00027456c>] handle_fasteoi_irq+0xb4/0x124
> [173.603777] [<ffffffc00026fe3c>] generic_handle_irq+0x30/0x44
> [173.603804] [<ffffffc0002701a8>] __handle_domain_irq+0x90/0xbc
> [173.603827] [<ffffffc0002006f4>] gic_handle_irq+0xcc/0x188
> ...
> [173.604500] [<ffffffc000203700>] el1_irq+0x80/0xf8
> [173.604530] [<ffffffc000261388>] cpu_startup_entry+0x38/0x3cc
> [173.604558] [<ffffffc00090f7d8>] rest_init+0x8c/0x94
> [173.604585] [<ffffffc000e009ac>] start_kernel+0x3d0/0x3fc
> [173.604607] [<0000000000b16000>] 0xb16000
> [173.604622] handlers:
> [173.604648] [<ffffffc000642084>] usb_hcd_irq
> [173.604673] Disabling IRQ #228
> 
> Signed-off-by: William wu <wulf-TNX95d0MmH7DzftRWevZcw@public.gmane.org>
> Signed-off-by: William wu <william.wu-TNX95d0MmH7DzftRWevZcw@public.gmane.org>
> ---
>  drivers/usb/core/hcd.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
> index 479e223..612fab6 100644
> --- a/drivers/usb/core/hcd.c
> +++ b/drivers/usb/core/hcd.c
> @@ -3017,6 +3017,7 @@ void usb_remove_hcd(struct usb_hcd *hcd)
>  	}
>  
>  	usb_put_invalidate_rhdev(hcd);
> +	hcd->flags = 0;
>  }
>  EXPORT_SYMBOL_GPL(usb_remove_hcd);
>  
> 
I suggest to initialize hcd->flags to 0 in usb_add_hcd() instead.

cheers,
-roger

Re: [PATCH] usb: hcd: initialize hcd->flags to 0 when rm hcd

[Alan Stern]

On Thu, 12 Jan 2017, Roger Quadros wrote:

> William,
> 
> On 12/01/17 14:03, William Wu wrote:
> > From: William wu <wulf-TNX95d0MmH7DzftRWevZcw@public.gmane.org>
> > 
> > On some platforms(e.g. rk3399 board), we can call hcd_add/remove
> > consecutively without calling usb_put_hcd/usb_create_hcd in between,
> > so hcd->flags can be stale.
> > 
> > If the HC dies due to whatever reason then without this patch we get
> > the below error on next hcd_add.
> > 
> > [173.296154] xhci-hcd xhci-hcd.2.auto: HC died; cleaning up
> > [173.296209] xhci-hcd xhci-hcd.2.auto: xHCI Host Controller
> > [173.296762] xhci-hcd xhci-hcd.2.auto: new USB bus registered, assigned bus number 6
> > [173.296931] usb usb6: We don't know the algorithms for LPM for this host, disabling LPM.
> > [173.297179] usb usb6: New USB device found, idVendor=1d6b, idProduct=0003
> > [173.297203] usb usb6: New USB device strings: Mfr=3, Product=2, SerialNumber=1
> > [173.297222] usb usb6: Product: xHCI Host Controller
> > [173.297240] usb usb6: Manufacturer: Linux 4.4.21 xhci-hcd
> > [173.297257] usb usb6: SerialNumber: xhci-hcd.2.auto
> > [173.298680] hub 6-0:1.0: USB hub found
> > [173.298749] hub 6-0:1.0: 1 port detected
> > [173.299382] rockchip-dwc3 usb@fe800000: USB HOST connected
> > [173.395418] hub 5-0:1.0: activate --> -19
> > [173.603447] irq 228: nobody cared (try booting with the "irqpoll" option)
> > [173.603493] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.4.21 #9
> > [173.603513] Hardware name: Google Kevin (DT)
> > [173.603531] Call trace:
> > [173.603568] [<ffffffc0002087dc>] dump_backtrace+0x0/0x160
> > [173.603596] [<ffffffc00020895c>] show_stack+0x20/0x28
> > [173.603623] [<ffffffc0004b28a8>] dump_stack+0x90/0xb0
> > [173.603650] [<ffffffc00027347c>] __report_bad_irq+0x48/0xe8
> > [173.603674] [<ffffffc0002737cc>] note_interrupt+0x1e8/0x28c
> > [173.603698] [<ffffffc000270a38>] handle_irq_event_percpu+0x1d4/0x25c
> > [173.603722] [<ffffffc000270b0c>] handle_irq_event+0x4c/0x7c
> > [173.603748] [<ffffffc00027456c>] handle_fasteoi_irq+0xb4/0x124
> > [173.603777] [<ffffffc00026fe3c>] generic_handle_irq+0x30/0x44
> > [173.603804] [<ffffffc0002701a8>] __handle_domain_irq+0x90/0xbc
> > [173.603827] [<ffffffc0002006f4>] gic_handle_irq+0xcc/0x188
> > ...
> > [173.604500] [<ffffffc000203700>] el1_irq+0x80/0xf8
> > [173.604530] [<ffffffc000261388>] cpu_startup_entry+0x38/0x3cc
> > [173.604558] [<ffffffc00090f7d8>] rest_init+0x8c/0x94
> > [173.604585] [<ffffffc000e009ac>] start_kernel+0x3d0/0x3fc
> > [173.604607] [<0000000000b16000>] 0xb16000
> > [173.604622] handlers:
> > [173.604648] [<ffffffc000642084>] usb_hcd_irq
> > [173.604673] Disabling IRQ #228
> > 
> > Signed-off-by: William wu <wulf-TNX95d0MmH7DzftRWevZcw@public.gmane.org>
> > Signed-off-by: William wu <william.wu-TNX95d0MmH7DzftRWevZcw@public.gmane.org>
> > ---
> >  drivers/usb/core/hcd.c | 1 +
> >  1 file changed, 1 insertion(+)
> > 
> > diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
> > index 479e223..612fab6 100644
> > --- a/drivers/usb/core/hcd.c
> > +++ b/drivers/usb/core/hcd.c
> > @@ -3017,6 +3017,7 @@ void usb_remove_hcd(struct usb_hcd *hcd)
> >  	}
> >  
> >  	usb_put_invalidate_rhdev(hcd);
> > +	hcd->flags = 0;
> >  }
> >  EXPORT_SYMBOL_GPL(usb_remove_hcd);
> >  
> > 
> I suggest to initialize hcd->flags to 0 in usb_add_hcd() instead.
> 
> cheers,
> -roger

Roger, didn't you originally propose this very same patch in

	http://marc.info/?l=linux-usb&m=146556415503583&w=2

(and of course, the earlier versions before v10)?  What happened to it?

Alan Stern

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Re: [PATCH] usb: hcd: initialize hcd->flags to 0 when rm hcd

[Roger Quadros]

On 12/01/17 17:33, Alan Stern wrote:
> On Thu, 12 Jan 2017, Roger Quadros wrote:
> 
>> William,
>>
>> On 12/01/17 14:03, William Wu wrote:
>>> From: William wu <wulf-TNX95d0MmH7DzftRWevZcw@public.gmane.org>
>>>
>>> On some platforms(e.g. rk3399 board), we can call hcd_add/remove
>>> consecutively without calling usb_put_hcd/usb_create_hcd in between,
>>> so hcd->flags can be stale.
>>>
>>> If the HC dies due to whatever reason then without this patch we get
>>> the below error on next hcd_add.
>>>
>>> [173.296154] xhci-hcd xhci-hcd.2.auto: HC died; cleaning up
>>> [173.296209] xhci-hcd xhci-hcd.2.auto: xHCI Host Controller
>>> [173.296762] xhci-hcd xhci-hcd.2.auto: new USB bus registered, assigned bus number 6
>>> [173.296931] usb usb6: We don't know the algorithms for LPM for this host, disabling LPM.
>>> [173.297179] usb usb6: New USB device found, idVendor=1d6b, idProduct=0003
>>> [173.297203] usb usb6: New USB device strings: Mfr=3, Product=2, SerialNumber=1
>>> [173.297222] usb usb6: Product: xHCI Host Controller
>>> [173.297240] usb usb6: Manufacturer: Linux 4.4.21 xhci-hcd
>>> [173.297257] usb usb6: SerialNumber: xhci-hcd.2.auto
>>> [173.298680] hub 6-0:1.0: USB hub found
>>> [173.298749] hub 6-0:1.0: 1 port detected
>>> [173.299382] rockchip-dwc3 usb@fe800000: USB HOST connected
>>> [173.395418] hub 5-0:1.0: activate --> -19
>>> [173.603447] irq 228: nobody cared (try booting with the "irqpoll" option)
>>> [173.603493] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.4.21 #9
>>> [173.603513] Hardware name: Google Kevin (DT)
>>> [173.603531] Call trace:
>>> [173.603568] [<ffffffc0002087dc>] dump_backtrace+0x0/0x160
>>> [173.603596] [<ffffffc00020895c>] show_stack+0x20/0x28
>>> [173.603623] [<ffffffc0004b28a8>] dump_stack+0x90/0xb0
>>> [173.603650] [<ffffffc00027347c>] __report_bad_irq+0x48/0xe8
>>> [173.603674] [<ffffffc0002737cc>] note_interrupt+0x1e8/0x28c
>>> [173.603698] [<ffffffc000270a38>] handle_irq_event_percpu+0x1d4/0x25c
>>> [173.603722] [<ffffffc000270b0c>] handle_irq_event+0x4c/0x7c
>>> [173.603748] [<ffffffc00027456c>] handle_fasteoi_irq+0xb4/0x124
>>> [173.603777] [<ffffffc00026fe3c>] generic_handle_irq+0x30/0x44
>>> [173.603804] [<ffffffc0002701a8>] __handle_domain_irq+0x90/0xbc
>>> [173.603827] [<ffffffc0002006f4>] gic_handle_irq+0xcc/0x188
>>> ...
>>> [173.604500] [<ffffffc000203700>] el1_irq+0x80/0xf8
>>> [173.604530] [<ffffffc000261388>] cpu_startup_entry+0x38/0x3cc
>>> [173.604558] [<ffffffc00090f7d8>] rest_init+0x8c/0x94
>>> [173.604585] [<ffffffc000e009ac>] start_kernel+0x3d0/0x3fc
>>> [173.604607] [<0000000000b16000>] 0xb16000
>>> [173.604622] handlers:
>>> [173.604648] [<ffffffc000642084>] usb_hcd_irq
>>> [173.604673] Disabling IRQ #228
>>>
>>> Signed-off-by: William wu <wulf-TNX95d0MmH7DzftRWevZcw@public.gmane.org>
>>> Signed-off-by: William wu <william.wu-TNX95d0MmH7DzftRWevZcw@public.gmane.org>
>>> ---
>>>  drivers/usb/core/hcd.c | 1 +
>>>  1 file changed, 1 insertion(+)
>>>
>>> diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
>>> index 479e223..612fab6 100644
>>> --- a/drivers/usb/core/hcd.c
>>> +++ b/drivers/usb/core/hcd.c
>>> @@ -3017,6 +3017,7 @@ void usb_remove_hcd(struct usb_hcd *hcd)
>>>  	}
>>>  
>>>  	usb_put_invalidate_rhdev(hcd);
>>> +	hcd->flags = 0;
>>>  }
>>>  EXPORT_SYMBOL_GPL(usb_remove_hcd);
>>>  
>>>
>> I suggest to initialize hcd->flags to 0 in usb_add_hcd() instead.
>>
>> cheers,
>> -roger
> 
> Roger, didn't you originally propose this very same patch in
> 
> 	http://marc.info/?l=linux-usb&m=146556415503583&w=2
> 
> (and of course, the earlier versions before v10)?  What happened to it?

Alan, You are right. That patch got lost in the ML. Looks like I didn't push it hard enough
and then forgot about it. Sorry.

William,

You don't need to do any changes. My earlier version was clearing the flag
in usb_add_hcd() and I guess Alan suggested to move it to usb_remove_hcd().

So your patch is good.
You can add my.

Acked-by: Roger Quadros <rogerq-l0cyMroinI0@public.gmane.org>

cheers,
-roger

Re: [PATCH] usb: hcd: initialize hcd->flags to 0 when rm hcd

[wlf]

Hi Roger，

在 2017年01月12日 23:38, Roger Quadros 写道:
> On 12/01/17 17:33, Alan Stern wrote:
>> On Thu, 12 Jan 2017, Roger Quadros wrote:
>>
>>> William,
>>>
>>> On 12/01/17 14:03, William Wu wrote:
>>>> From: William wu <wulf-TNX95d0MmH7DzftRWevZcw@public.gmane.org>
>>>>
>>>> On some platforms(e.g. rk3399 board), we can call hcd_add/remove
>>>> consecutively without calling usb_put_hcd/usb_create_hcd in between,
>>>> so hcd->flags can be stale.
>>>>
>>>> If the HC dies due to whatever reason then without this patch we get
>>>> the below error on next hcd_add.
>>>>
>>>> [173.296154] xhci-hcd xhci-hcd.2.auto: HC died; cleaning up
>>>> [173.296209] xhci-hcd xhci-hcd.2.auto: xHCI Host Controller
>>>> [173.296762] xhci-hcd xhci-hcd.2.auto: new USB bus registered, assigned bus number 6
>>>> [173.296931] usb usb6: We don't know the algorithms for LPM for this host, disabling LPM.
>>>> [173.297179] usb usb6: New USB device found, idVendor=1d6b, idProduct=0003
>>>> [173.297203] usb usb6: New USB device strings: Mfr=3, Product=2, SerialNumber=1
>>>> [173.297222] usb usb6: Product: xHCI Host Controller
>>>> [173.297240] usb usb6: Manufacturer: Linux 4.4.21 xhci-hcd
>>>> [173.297257] usb usb6: SerialNumber: xhci-hcd.2.auto
>>>> [173.298680] hub 6-0:1.0: USB hub found
>>>> [173.298749] hub 6-0:1.0: 1 port detected
>>>> [173.299382] rockchip-dwc3 usb@fe800000: USB HOST connected
>>>> [173.395418] hub 5-0:1.0: activate --> -19
>>>> [173.603447] irq 228: nobody cared (try booting with the "irqpoll" option)
>>>> [173.603493] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.4.21 #9
>>>> [173.603513] Hardware name: Google Kevin (DT)
>>>> [173.603531] Call trace:
>>>> [173.603568] [<ffffffc0002087dc>] dump_backtrace+0x0/0x160
>>>> [173.603596] [<ffffffc00020895c>] show_stack+0x20/0x28
>>>> [173.603623] [<ffffffc0004b28a8>] dump_stack+0x90/0xb0
>>>> [173.603650] [<ffffffc00027347c>] __report_bad_irq+0x48/0xe8
>>>> [173.603674] [<ffffffc0002737cc>] note_interrupt+0x1e8/0x28c
>>>> [173.603698] [<ffffffc000270a38>] handle_irq_event_percpu+0x1d4/0x25c
>>>> [173.603722] [<ffffffc000270b0c>] handle_irq_event+0x4c/0x7c
>>>> [173.603748] [<ffffffc00027456c>] handle_fasteoi_irq+0xb4/0x124
>>>> [173.603777] [<ffffffc00026fe3c>] generic_handle_irq+0x30/0x44
>>>> [173.603804] [<ffffffc0002701a8>] __handle_domain_irq+0x90/0xbc
>>>> [173.603827] [<ffffffc0002006f4>] gic_handle_irq+0xcc/0x188
>>>> ...
>>>> [173.604500] [<ffffffc000203700>] el1_irq+0x80/0xf8
>>>> [173.604530] [<ffffffc000261388>] cpu_startup_entry+0x38/0x3cc
>>>> [173.604558] [<ffffffc00090f7d8>] rest_init+0x8c/0x94
>>>> [173.604585] [<ffffffc000e009ac>] start_kernel+0x3d0/0x3fc
>>>> [173.604607] [<0000000000b16000>] 0xb16000
>>>> [173.604622] handlers:
>>>> [173.604648] [<ffffffc000642084>] usb_hcd_irq
>>>> [173.604673] Disabling IRQ #228
>>>>
>>>> Signed-off-by: William wu <wulf-TNX95d0MmH7DzftRWevZcw@public.gmane.org>
>>>> Signed-off-by: William wu <william.wu-TNX95d0MmH7DzftRWevZcw@public.gmane.org>
>>>> ---
>>>>   drivers/usb/core/hcd.c | 1 +
>>>>   1 file changed, 1 insertion(+)
>>>>
>>>> diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
>>>> index 479e223..612fab6 100644
>>>> --- a/drivers/usb/core/hcd.c
>>>> +++ b/drivers/usb/core/hcd.c
>>>> @@ -3017,6 +3017,7 @@ void usb_remove_hcd(struct usb_hcd *hcd)
>>>>   	}
>>>>   
>>>>   	usb_put_invalidate_rhdev(hcd);
>>>> +	hcd->flags = 0;
>>>>   }
>>>>   EXPORT_SYMBOL_GPL(usb_remove_hcd);
>>>>   
>>>>
>>> I suggest to initialize hcd->flags to 0 in usb_add_hcd() instead.
>>>
>>> cheers,
>>> -roger
>> Roger, didn't you originally propose this very same patch in
>>
>> 	http://marc.info/?l=linux-usb&m=146556415503583&w=2
>>
>> (and of course, the earlier versions before v10)?  What happened to it?
> Alan, You are right. That patch got lost in the ML. Looks like I didn't push it hard enough
> and then forgot about it. Sorry.
>
> William,
>
> You don't need to do any changes. My earlier version was clearing the flag
> in usb_add_hcd() and I guess Alan suggested to move it to usb_remove_hcd().
>
> So your patch is good.
> You can add my.
>
> Acked-by: Roger Quadros <rogerq-l0cyMroinI0@public.gmane.org>
>
> cheers,
> -roger
Thanks very much for your suggestion，I  will add acked-by immediately.
>
>
>


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[RESEND PATCH] usb: hcd: initialize hcd->flags to 0 when rm hcd

[William Wu]

From: William wu <wulf-TNX95d0MmH7DzftRWevZcw@public.gmane.org>

On some platforms(e.g. rk3399 board), we can call hcd_add/remove
consecutively without calling usb_put_hcd/usb_create_hcd in between,
so hcd->flags can be stale.

If the HC dies due to whatever reason then without this patch we get
the below error on next hcd_add.

[173.296154] xhci-hcd xhci-hcd.2.auto: HC died; cleaning up
[173.296209] xhci-hcd xhci-hcd.2.auto: xHCI Host Controller
[173.296762] xhci-hcd xhci-hcd.2.auto: new USB bus registered, assigned bus number 6
[173.296931] usb usb6: We don't know the algorithms for LPM for this host, disabling LPM.
[173.297179] usb usb6: New USB device found, idVendor=1d6b, idProduct=0003
[173.297203] usb usb6: New USB device strings: Mfr=3, Product=2, SerialNumber=1
[173.297222] usb usb6: Product: xHCI Host Controller
[173.297240] usb usb6: Manufacturer: Linux 4.4.21 xhci-hcd
[173.297257] usb usb6: SerialNumber: xhci-hcd.2.auto
[173.298680] hub 6-0:1.0: USB hub found
[173.298749] hub 6-0:1.0: 1 port detected
[173.299382] rockchip-dwc3 usb@fe800000: USB HOST connected
[173.395418] hub 5-0:1.0: activate --> -19
[173.603447] irq 228: nobody cared (try booting with the "irqpoll" option)
[173.603493] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.4.21 #9
[173.603513] Hardware name: Google Kevin (DT)
[173.603531] Call trace:
[173.603568] [<ffffffc0002087dc>] dump_backtrace+0x0/0x160
[173.603596] [<ffffffc00020895c>] show_stack+0x20/0x28
[173.603623] [<ffffffc0004b28a8>] dump_stack+0x90/0xb0
[173.603650] [<ffffffc00027347c>] __report_bad_irq+0x48/0xe8
[173.603674] [<ffffffc0002737cc>] note_interrupt+0x1e8/0x28c
[173.603698] [<ffffffc000270a38>] handle_irq_event_percpu+0x1d4/0x25c
[173.603722] [<ffffffc000270b0c>] handle_irq_event+0x4c/0x7c
[173.603748] [<ffffffc00027456c>] handle_fasteoi_irq+0xb4/0x124
[173.603777] [<ffffffc00026fe3c>] generic_handle_irq+0x30/0x44
[173.603804] [<ffffffc0002701a8>] __handle_domain_irq+0x90/0xbc
[173.603827] [<ffffffc0002006f4>] gic_handle_irq+0xcc/0x188
...
[173.604500] [<ffffffc000203700>] el1_irq+0x80/0xf8
[173.604530] [<ffffffc000261388>] cpu_startup_entry+0x38/0x3cc
[173.604558] [<ffffffc00090f7d8>] rest_init+0x8c/0x94
[173.604585] [<ffffffc000e009ac>] start_kernel+0x3d0/0x3fc
[173.604607] [<0000000000b16000>] 0xb16000
[173.604622] handlers:
[173.604648] [<ffffffc000642084>] usb_hcd_irq
[173.604673] Disabling IRQ #228

Signed-off-by: William wu <wulf-TNX95d0MmH7DzftRWevZcw@public.gmane.org>
Acked-by: Roger Quadros <rogerq-l0cyMroinI0@public.gmane.org>
---
 drivers/usb/core/hcd.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
index 479e223..612fab6 100644
--- a/drivers/usb/core/hcd.c
+++ b/drivers/usb/core/hcd.c
@@ -3017,6 +3017,7 @@ void usb_remove_hcd(struct usb_hcd *hcd)
 	}
 
 	usb_put_invalidate_rhdev(hcd);
+	hcd->flags = 0;
 }
 EXPORT_SYMBOL_GPL(usb_remove_hcd);
 
-- 
2.7.4