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[PATCH v8 4/9] usb: dwc3: core: Skip setting event buffers for host only controllers

Krishna Kurapati posted 9 patches 2 years, 9 months ago
There is a newer version of this series
[PATCH v8 4/9] usb: dwc3: core: Skip setting event buffers for host only controllers
Posted by Krishna Kurapati 2 years, 9 months ago 
On some SoC's like SA8295P where the tertiary controller is host-only
capable, GEVTADDRHI/LO, GEVTSIZ, GEVTCOUNT registers are not accessible.
Trying to setup them up during core_init leads to a crash.

For DRD/Peripheral supported controllers, event buffer setup is done
again in gadget_pullup. Skip setup or cleanup of event buffers if
controller is host-only capable.

Signed-off-by: Krishna Kurapati <quic_kriskura@quicinc.com>
---
 drivers/usb/dwc3/core.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index e983aef1fb93..46192d08d1b6 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -505,6 +505,11 @@ static int dwc3_alloc_event_buffers(struct dwc3 *dwc, unsigned int length)
 int dwc3_event_buffers_setup(struct dwc3 *dwc)
 {
 	struct dwc3_event_buffer	*evt;
+	unsigned int			hw_mode;
+
+	hw_mode = DWC3_GHWPARAMS0_MODE(dwc->hwparams.hwparams0);
+	if (hw_mode == DWC3_GHWPARAMS0_MODE_HOST)
+		return 0;
 
 	evt = dwc->ev_buf;
 	evt->lpos = 0;
@@ -522,6 +527,11 @@ int dwc3_event_buffers_setup(struct dwc3 *dwc)
 void dwc3_event_buffers_cleanup(struct dwc3 *dwc)
 {
 	struct dwc3_event_buffer	*evt;
+	unsigned int			hw_mode;
+
+	hw_mode = DWC3_GHWPARAMS0_MODE(dwc->hwparams.hwparams0);
+	if (hw_mode == DWC3_GHWPARAMS0_MODE_HOST)
+		return;
 
 	evt = dwc->ev_buf;
 
-- 
2.40.0
Re: [PATCH v8 4/9] usb: dwc3: core: Skip setting event buffers for host only controllers
Posted by Johan Hovold 2 years, 9 months ago 
On Sun, May 14, 2023 at 11:19:12AM +0530, Krishna Kurapati wrote:
> On some SoC's like SA8295P where the tertiary controller is host-only
> capable, GEVTADDRHI/LO, GEVTSIZ, GEVTCOUNT registers are not accessible.
> Trying to setup them up during core_init leads to a crash.
> 
> For DRD/Peripheral supported controllers, event buffer setup is done
> again in gadget_pullup. Skip setup or cleanup of event buffers if
> controller is host-only capable.
> 
> Signed-off-by: Krishna Kurapati <quic_kriskura@quicinc.com>
> ---
>  drivers/usb/dwc3/core.c | 10 ++++++++++
>  1 file changed, 10 insertions(+)
> 
> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
> index e983aef1fb93..46192d08d1b6 100644
> --- a/drivers/usb/dwc3/core.c
> +++ b/drivers/usb/dwc3/core.c
> @@ -505,6 +505,11 @@ static int dwc3_alloc_event_buffers(struct dwc3 *dwc, unsigned int length)
>  int dwc3_event_buffers_setup(struct dwc3 *dwc)
>  {
>  	struct dwc3_event_buffer	*evt;
> +	unsigned int			hw_mode;
> +
> +	hw_mode = DWC3_GHWPARAMS0_MODE(dwc->hwparams.hwparams0);
> +	if (hw_mode == DWC3_GHWPARAMS0_MODE_HOST)
> +		return 0;
>  
>  	evt = dwc->ev_buf;

How about adding this check to dwc3_alloc_event_buffers() instead as
there should be no need to allocate buffer that you never use?

Then you can just check dwc->ev_buf here and elsewhere.

Johan
Re: [PATCH v8 4/9] usb: dwc3: core: Skip setting event buffers for host only controllers
Posted by Krishna Kurapati PSSNV 2 years, 8 months ago 

On 5/16/2023 5:47 PM, Johan Hovold wrote:
> On Sun, May 14, 2023 at 11:19:12AM +0530, Krishna Kurapati wrote:
>> On some SoC's like SA8295P where the tertiary controller is host-only
>> capable, GEVTADDRHI/LO, GEVTSIZ, GEVTCOUNT registers are not accessible.
>> Trying to setup them up during core_init leads to a crash.
>>
>> For DRD/Peripheral supported controllers, event buffer setup is done
>> again in gadget_pullup. Skip setup or cleanup of event buffers if
>> controller is host-only capable.
>>
>> Signed-off-by: Krishna Kurapati <quic_kriskura@quicinc.com>
>> ---
>>   drivers/usb/dwc3/core.c | 10 ++++++++++
>>   1 file changed, 10 insertions(+)
>>
>> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
>> index e983aef1fb93..46192d08d1b6 100644
>> --- a/drivers/usb/dwc3/core.c
>> +++ b/drivers/usb/dwc3/core.c
>> @@ -505,6 +505,11 @@ static int dwc3_alloc_event_buffers(struct dwc3 *dwc, unsigned int length)
>>   int dwc3_event_buffers_setup(struct dwc3 *dwc)
>>   {
>>   	struct dwc3_event_buffer	*evt;
>> +	unsigned int			hw_mode;
>> +
>> +	hw_mode = DWC3_GHWPARAMS0_MODE(dwc->hwparams.hwparams0);
>> +	if (hw_mode == DWC3_GHWPARAMS0_MODE_HOST)
>> +		return 0;
>>   
>>   	evt = dwc->ev_buf;
> 
> How about adding this check to dwc3_alloc_event_buffers() instead as
> there should be no need to allocate buffer that you never use?
> 
> Then you can just check dwc->ev_buf here and elsewhere.
> 

Thanks for this idea. We can save 4096 bytes from being allocated this 
way. Will get this in next version.

Regards,
Krishna,
Re: [PATCH v8 4/9] usb: dwc3: core: Skip setting event buffers for host only controllers
Posted by Bjorn Andersson 2 years, 9 months ago 
On Sun, May 14, 2023 at 11:19:12AM +0530, Krishna Kurapati wrote:
> On some SoC's like SA8295P where the tertiary controller is host-only

Please add "Qualcomm" before SA8295P.

> capable, GEVTADDRHI/LO, GEVTSIZ, GEVTCOUNT registers are not accessible.
> Trying to setup them up during core_init leads to a crash.

s/setup/access/ (or "write to"?) and presumably this is a problem beyond
core_init, so I would suggest dropping "up during core_init" from the
sentence.

> 
> For DRD/Peripheral supported controllers, event buffer setup is done
> again in gadget_pullup. Skip setup or cleanup of event buffers if
> controller is host-only capable.
> 

With that, this looks reasonable to me.

Reviewed-by: Bjorn Andersson <andersson@kernel.org>

Regards,
Bjorn

> Signed-off-by: Krishna Kurapati <quic_kriskura@quicinc.com>
> ---
>  drivers/usb/dwc3/core.c | 10 ++++++++++
>  1 file changed, 10 insertions(+)
> 
> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
> index e983aef1fb93..46192d08d1b6 100644
> --- a/drivers/usb/dwc3/core.c
> +++ b/drivers/usb/dwc3/core.c
> @@ -505,6 +505,11 @@ static int dwc3_alloc_event_buffers(struct dwc3 *dwc, unsigned int length)
>  int dwc3_event_buffers_setup(struct dwc3 *dwc)
>  {
>  	struct dwc3_event_buffer	*evt;
> +	unsigned int			hw_mode;
> +
> +	hw_mode = DWC3_GHWPARAMS0_MODE(dwc->hwparams.hwparams0);
> +	if (hw_mode == DWC3_GHWPARAMS0_MODE_HOST)
> +		return 0;
>  
>  	evt = dwc->ev_buf;
>  	evt->lpos = 0;
> @@ -522,6 +527,11 @@ int dwc3_event_buffers_setup(struct dwc3 *dwc)
>  void dwc3_event_buffers_cleanup(struct dwc3 *dwc)
>  {
>  	struct dwc3_event_buffer	*evt;
> +	unsigned int			hw_mode;
> +
> +	hw_mode = DWC3_GHWPARAMS0_MODE(dwc->hwparams.hwparams0);
> +	if (hw_mode == DWC3_GHWPARAMS0_MODE_HOST)
> +		return;
>  
>  	evt = dwc->ev_buf;
>  
> -- 
> 2.40.0
>

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