diff mbox series

[RFC,v2,3/3] usb: dwc3: Issue core soft reset before enabling run/stop

Message ID 20220216000835.25400-4-quic_wcheng@quicinc.com (mailing list archive)
State New, archived
Headers show
Series Fix enumeration issues during composition switching | expand

Commit Message

Wesley Cheng Feb. 16, 2022, 12:08 a.m. UTC 
It is recommended by the Synopsis databook to issue a DCTL.CSftReset
when reconnecting from a device-initiated disconnect routine.  This
resolves issues with enumeration during fast composition switching
cases, which result in an unknown device on the host.

Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
---
 drivers/usb/dwc3/core.c   |  4 +---
 drivers/usb/dwc3/core.h   |  2 ++
 drivers/usb/dwc3/gadget.c | 11 +++++++++++
 3 files changed, 14 insertions(+), 3 deletions(-)

Comments

Jung Daehwan Feb. 17, 2022, 5:52 a.m. UTC | #1 
Hi wesley,

On Tue, Feb 15, 2022 at 04:08:35PM -0800, Wesley Cheng wrote:
> It is recommended by the Synopsis databook to issue a DCTL.CSftReset
> when reconnecting from a device-initiated disconnect routine.  This
> resolves issues with enumeration during fast composition switching
> cases, which result in an unknown device on the host.
> 
> Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
> ---
>  drivers/usb/dwc3/core.c   |  4 +---
>  drivers/usb/dwc3/core.h   |  2 ++
>  drivers/usb/dwc3/gadget.c | 11 +++++++++++
>  3 files changed, 14 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
> index 18adddfba3da..02d10e1cb774 100644
> --- a/drivers/usb/dwc3/core.c
> +++ b/drivers/usb/dwc3/core.c
> @@ -115,8 +115,6 @@ void dwc3_set_prtcap(struct dwc3 *dwc, u32 mode)
>  	dwc->current_dr_role = mode;
>  }
>  
> -static int dwc3_core_soft_reset(struct dwc3 *dwc);
> -
>  static void __dwc3_set_mode(struct work_struct *work)
>  {
>  	struct dwc3 *dwc = work_to_dwc(work);
> @@ -261,7 +259,7 @@ u32 dwc3_core_fifo_space(struct dwc3_ep *dep, u8 type)
>   * dwc3_core_soft_reset - Issues core soft reset and PHY reset
>   * @dwc: pointer to our context structure
>   */
> -static int dwc3_core_soft_reset(struct dwc3 *dwc)
> +int dwc3_core_soft_reset(struct dwc3 *dwc)
>  {
>  	u32		reg;
>  	int		retries = 1000;
> diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
> index 00348d6d479b..b27ad8dad317 100644
> --- a/drivers/usb/dwc3/core.h
> +++ b/drivers/usb/dwc3/core.h
> @@ -1532,6 +1532,8 @@ bool dwc3_has_imod(struct dwc3 *dwc);
>  int dwc3_event_buffers_setup(struct dwc3 *dwc);
>  void dwc3_event_buffers_cleanup(struct dwc3 *dwc);
>  
> +int dwc3_core_soft_reset(struct dwc3 *dwc);
> +
>  #if IS_ENABLED(CONFIG_USB_DWC3_HOST) || IS_ENABLED(CONFIG_USB_DWC3_DUAL_ROLE)
>  int dwc3_host_init(struct dwc3 *dwc);
>  void dwc3_host_exit(struct dwc3 *dwc);
> diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
> index 0c89baedf220..788889f924f9 100644
> --- a/drivers/usb/dwc3/gadget.c
> +++ b/drivers/usb/dwc3/gadget.c
> @@ -2585,6 +2585,17 @@ static int dwc3_gadget_pullup(struct usb_gadget *g, int is_on)
>  						dwc->ev_buf->length;
>  		}
>  	} else {
> +		/*
> +		 * In the Synopsis DesignWare Cores USB3 Databook Rev. 1.90a
> +		 * Section 4.1.9, it specifies that for a reconnect after a
> +		 * device-initiated disconnect requires a core soft reset
> +		 * (DCTL.CSftRst) before enabling the run/stop bit.
> +		 */
> +		spin_unlock_irqrestore(&dwc->lock, flags);
> +		dwc3_core_soft_reset(dwc);
> +		spin_lock_irqsave(&dwc->lock, flags);
> +
> +		dwc3_event_buffers_setup(dwc);

Could you tell me why you add dwc3_event_buffer_setup?

Best Regards,
Jung Daehwan

>  		__dwc3_gadget_start(dwc);
>  	}
>  
>
Jung Daehwan Feb. 17, 2022, 9:43 a.m. UTC | #2 
On Thu, Feb 17, 2022 at 02:52:14PM +0900, Jung Daehwan wrote:
> Hi wesley,
> 
> On Tue, Feb 15, 2022 at 04:08:35PM -0800, Wesley Cheng wrote:
> > It is recommended by the Synopsis databook to issue a DCTL.CSftReset
> > when reconnecting from a device-initiated disconnect routine.  This
> > resolves issues with enumeration during fast composition switching
> > cases, which result in an unknown device on the host.
> > 
> > Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
> > ---
> >  drivers/usb/dwc3/core.c   |  4 +---
> >  drivers/usb/dwc3/core.h   |  2 ++
> >  drivers/usb/dwc3/gadget.c | 11 +++++++++++
> >  3 files changed, 14 insertions(+), 3 deletions(-)
> > 
> > diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
> > index 18adddfba3da..02d10e1cb774 100644
> > --- a/drivers/usb/dwc3/core.c
> > +++ b/drivers/usb/dwc3/core.c
> > @@ -115,8 +115,6 @@ void dwc3_set_prtcap(struct dwc3 *dwc, u32 mode)
> >  	dwc->current_dr_role = mode;
> >  }
> >  
> > -static int dwc3_core_soft_reset(struct dwc3 *dwc);
> > -
> >  static void __dwc3_set_mode(struct work_struct *work)
> >  {
> >  	struct dwc3 *dwc = work_to_dwc(work);
> > @@ -261,7 +259,7 @@ u32 dwc3_core_fifo_space(struct dwc3_ep *dep, u8 type)
> >   * dwc3_core_soft_reset - Issues core soft reset and PHY reset
> >   * @dwc: pointer to our context structure
> >   */
> > -static int dwc3_core_soft_reset(struct dwc3 *dwc)
> > +int dwc3_core_soft_reset(struct dwc3 *dwc)
> >  {
> >  	u32		reg;
> >  	int		retries = 1000;
> > diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
> > index 00348d6d479b..b27ad8dad317 100644
> > --- a/drivers/usb/dwc3/core.h
> > +++ b/drivers/usb/dwc3/core.h
> > @@ -1532,6 +1532,8 @@ bool dwc3_has_imod(struct dwc3 *dwc);
> >  int dwc3_event_buffers_setup(struct dwc3 *dwc);
> >  void dwc3_event_buffers_cleanup(struct dwc3 *dwc);
> >  
> > +int dwc3_core_soft_reset(struct dwc3 *dwc);
> > +
> >  #if IS_ENABLED(CONFIG_USB_DWC3_HOST) || IS_ENABLED(CONFIG_USB_DWC3_DUAL_ROLE)
> >  int dwc3_host_init(struct dwc3 *dwc);
> >  void dwc3_host_exit(struct dwc3 *dwc);
> > diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
> > index 0c89baedf220..788889f924f9 100644
> > --- a/drivers/usb/dwc3/gadget.c
> > +++ b/drivers/usb/dwc3/gadget.c
> > @@ -2585,6 +2585,17 @@ static int dwc3_gadget_pullup(struct usb_gadget *g, int is_on)
> >  						dwc->ev_buf->length;
> >  		}
> >  	} else {
> > +		/*
> > +		 * In the Synopsis DesignWare Cores USB3 Databook Rev. 1.90a
> > +		 * Section 4.1.9, it specifies that for a reconnect after a
> > +		 * device-initiated disconnect requires a core soft reset
> > +		 * (DCTL.CSftRst) before enabling the run/stop bit.
> > +		 */
> > +		spin_unlock_irqrestore(&dwc->lock, flags);
> > +		dwc3_core_soft_reset(dwc);
> > +		spin_lock_irqsave(&dwc->lock, flags);
> > +
> > +		dwc3_event_buffers_setup(dwc);
> 
> Could you tell me why you add dwc3_event_buffer_setup?
> 
> Best Regards,
> Jung Daehwan
> 

I'm sorry I misunderstood databook then. It seems to be needed.

Best Regrards,
Jung Daehwan

> >  		__dwc3_gadget_start(dwc);
> >  	}
> >  
> >
Wesley Cheng Feb. 17, 2022, 7:01 p.m. UTC | #3 
Hi Daehwan,

On 2/16/2022 9:52 PM, Jung Daehwan wrote:
> Hi wesley,
> 
> On Tue, Feb 15, 2022 at 04:08:35PM -0800, Wesley Cheng wrote:
>> It is recommended by the Synopsis databook to issue a DCTL.CSftReset
>> when reconnecting from a device-initiated disconnect routine.  This
>> resolves issues with enumeration during fast composition switching
>> cases, which result in an unknown device on the host.
>>
>> Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
>> ---
>>  drivers/usb/dwc3/core.c   |  4 +---
>>  drivers/usb/dwc3/core.h   |  2 ++
>>  drivers/usb/dwc3/gadget.c | 11 +++++++++++
>>  3 files changed, 14 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
>> index 18adddfba3da..02d10e1cb774 100644
>> --- a/drivers/usb/dwc3/core.c
>> +++ b/drivers/usb/dwc3/core.c
>> @@ -115,8 +115,6 @@ void dwc3_set_prtcap(struct dwc3 *dwc, u32 mode)
>>  	dwc->current_dr_role = mode;
>>  }
>>  
>> -static int dwc3_core_soft_reset(struct dwc3 *dwc);
>> -
>>  static void __dwc3_set_mode(struct work_struct *work)
>>  {
>>  	struct dwc3 *dwc = work_to_dwc(work);
>> @@ -261,7 +259,7 @@ u32 dwc3_core_fifo_space(struct dwc3_ep *dep, u8 type)
>>   * dwc3_core_soft_reset - Issues core soft reset and PHY reset
>>   * @dwc: pointer to our context structure
>>   */
>> -static int dwc3_core_soft_reset(struct dwc3 *dwc)
>> +int dwc3_core_soft_reset(struct dwc3 *dwc)
>>  {
>>  	u32		reg;
>>  	int		retries = 1000;
>> diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
>> index 00348d6d479b..b27ad8dad317 100644
>> --- a/drivers/usb/dwc3/core.h
>> +++ b/drivers/usb/dwc3/core.h
>> @@ -1532,6 +1532,8 @@ bool dwc3_has_imod(struct dwc3 *dwc);
>>  int dwc3_event_buffers_setup(struct dwc3 *dwc);
>>  void dwc3_event_buffers_cleanup(struct dwc3 *dwc);
>>  
>> +int dwc3_core_soft_reset(struct dwc3 *dwc);
>> +
>>  #if IS_ENABLED(CONFIG_USB_DWC3_HOST) || IS_ENABLED(CONFIG_USB_DWC3_DUAL_ROLE)
>>  int dwc3_host_init(struct dwc3 *dwc);
>>  void dwc3_host_exit(struct dwc3 *dwc);
>> diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
>> index 0c89baedf220..788889f924f9 100644
>> --- a/drivers/usb/dwc3/gadget.c
>> +++ b/drivers/usb/dwc3/gadget.c
>> @@ -2585,6 +2585,17 @@ static int dwc3_gadget_pullup(struct usb_gadget *g, int is_on)
>>  						dwc->ev_buf->length;
>>  		}
>>  	} else {
>> +		/*
>> +		 * In the Synopsis DesignWare Cores USB3 Databook Rev. 1.90a
>> +		 * Section 4.1.9, it specifies that for a reconnect after a
>> +		 * device-initiated disconnect requires a core soft reset
>> +		 * (DCTL.CSftRst) before enabling the run/stop bit.
>> +		 */
>> +		spin_unlock_irqrestore(&dwc->lock, flags);
>> +		dwc3_core_soft_reset(dwc);
>> +		spin_lock_irqsave(&dwc->lock, flags);
>> +
>> +		dwc3_event_buffers_setup(dwc);
> 
> Could you tell me why you add dwc3_event_buffer_setup?
> 
During my testing if the event buffer re-initialization is not there,
then it resulted in the controller attempting to access an invalid
address space after the soft reset completed. (SMMU fault w/ FAR=0x0)

Likewise, in other scenarios where core soft reset is called, there is
always an event buffer re-init following it.

Thanks
Wesley Cheng
diff mbox series

Patch

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index 18adddfba3da..02d10e1cb774 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -115,8 +115,6 @@  void dwc3_set_prtcap(struct dwc3 *dwc, u32 mode)
 	dwc->current_dr_role = mode;
 }
 
-static int dwc3_core_soft_reset(struct dwc3 *dwc);
-
 static void __dwc3_set_mode(struct work_struct *work)
 {
 	struct dwc3 *dwc = work_to_dwc(work);
@@ -261,7 +259,7 @@  u32 dwc3_core_fifo_space(struct dwc3_ep *dep, u8 type)
  * dwc3_core_soft_reset - Issues core soft reset and PHY reset
  * @dwc: pointer to our context structure
  */
-static int dwc3_core_soft_reset(struct dwc3 *dwc)
+int dwc3_core_soft_reset(struct dwc3 *dwc)
 {
 	u32		reg;
 	int		retries = 1000;
diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index 00348d6d479b..b27ad8dad317 100644
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -1532,6 +1532,8 @@  bool dwc3_has_imod(struct dwc3 *dwc);
 int dwc3_event_buffers_setup(struct dwc3 *dwc);
 void dwc3_event_buffers_cleanup(struct dwc3 *dwc);
 
+int dwc3_core_soft_reset(struct dwc3 *dwc);
+
 #if IS_ENABLED(CONFIG_USB_DWC3_HOST) || IS_ENABLED(CONFIG_USB_DWC3_DUAL_ROLE)
 int dwc3_host_init(struct dwc3 *dwc);
 void dwc3_host_exit(struct dwc3 *dwc);
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 0c89baedf220..788889f924f9 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -2585,6 +2585,17 @@  static int dwc3_gadget_pullup(struct usb_gadget *g, int is_on)
 						dwc->ev_buf->length;
 		}
 	} else {
+		/*
+		 * In the Synopsis DesignWare Cores USB3 Databook Rev. 1.90a
+		 * Section 4.1.9, it specifies that for a reconnect after a
+		 * device-initiated disconnect requires a core soft reset
+		 * (DCTL.CSftRst) before enabling the run/stop bit.
+		 */
+		spin_unlock_irqrestore(&dwc->lock, flags);
+		dwc3_core_soft_reset(dwc);
+		spin_lock_irqsave(&dwc->lock, flags);
+
+		dwc3_event_buffers_setup(dwc);
 		__dwc3_gadget_start(dwc);
 	}