Re: [PATCH v7 4/9] usb: dwc3: core: Skip setting event buffers for host only controllers

[Krishna Kurapati PSSNV <quic_kriskura@quicinc.com>]

On 5/3/2023 3:14 AM, Thinh Nguyen wrote:
> On Mon, May 01, 2023, 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 | 22 ++++++++++++++++------
>>   1 file changed, 16 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
>> index b8ac7bcee391..8625fc5c7ab4 100644
>> --- a/drivers/usb/dwc3/core.c
>> +++ b/drivers/usb/dwc3/core.c
>> @@ -835,7 +835,12 @@ static void dwc3_clk_disable(struct dwc3 *dwc)
>>   
>>   static void dwc3_core_exit(struct dwc3 *dwc)
>>   {
>> -	dwc3_event_buffers_cleanup(dwc);
>> +	unsigned int	hw_mode;
>> +
>> +	hw_mode = DWC3_GHWPARAMS0_MODE(dwc->hwparams.hwparams0);
>> +	if (hw_mode != DWC3_GHWPARAMS0_MODE_HOST)
>> +		dwc3_event_buffers_cleanup(dwc);
> 
> I think it's cleaner to do these checks in dwc3_event_buffers_cleanup
> and dwc3_event_buffers_setup.
> 
> Thanks,
> Thinh
> 

Hi Thinh,

  Good point. Will move these checks to respective functions in next 
version. Thanks for pointing it out.

Regards,
Krishna,
>> +
>>   	dwc3_phy_power_off(dwc);
>>   	dwc3_phy_exit(dwc);
>>   	dwc3_clk_disable(dwc);
>> @@ -1141,10 +1146,12 @@ static int dwc3_core_init(struct dwc3 *dwc)
>>   	if (ret)
>>   		goto err_exit_phy;
>>   
>> -	ret = dwc3_event_buffers_setup(dwc);
>> -	if (ret) {
>> -		dev_err(dwc->dev, "failed to setup event buffers\n");
>> -		goto err_power_off_phy;
>> +	if (hw_mode != DWC3_GHWPARAMS0_MODE_HOST) {
>> +		ret = dwc3_event_buffers_setup(dwc);
>> +		if (ret) {
>> +			dev_err(dwc->dev, "failed to setup event buffers\n");
>> +			goto err_power_off_phy;
>> +		}
>>   	}
>>   
>>   	/*
>> @@ -1958,7 +1965,10 @@ static int dwc3_probe(struct platform_device *pdev)
>>   
>>   err_exit_debugfs:
>>   	dwc3_debugfs_exit(dwc);
>> -	dwc3_event_buffers_cleanup(dwc);
>> +
>> +	if (hw_mode != DWC3_GHWPARAMS0_MODE_HOST)
>> +		dwc3_event_buffers_cleanup(dwc);
>> +
>>   	dwc3_phy_power_off(dwc);
>>   	dwc3_phy_exit(dwc);
>>   	dwc3_ulpi_exit(dwc);
>> -- 
>> 2.40.0