On 1/8/2018 4:01 AM, Felipe Balbi wrote:
>
> Hi,
>
> Thinh Nguyen <Thinh.Nguyen@xxxxxxxxxxxx> writes:
>> From DWC_usb31 databook section 1.3.2, once DWC3_DCTL_CSFTRST bit is
>> cleared, we must wait at least 50ms before accessing the PHY domain
>> (synchronization delay).
>>
>> Signed-off-by: Thinh Nguyen <thinhn@xxxxxxxxxxxx>
>> ---
>> drivers/usb/dwc3/core.c | 13 ++++++++++++-
>> 1 file changed, 12 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
>> index 07832509584f..7d21f21707f5 100644
>> --- a/drivers/usb/dwc3/core.c
>> +++ b/drivers/usb/dwc3/core.c
>> @@ -228,12 +228,23 @@ static int dwc3_core_soft_reset(struct dwc3 *dwc)
>> do {
>> reg = dwc3_readl(dwc->regs, DWC3_DCTL);
>> if (!(reg & DWC3_DCTL_CSFTRST))
>> - return 0;
>> + goto done;
>>
>> udelay(1);
>> } while (--retries);
>>
>> return -ETIMEDOUT;
>> +
>> +done:
>> + /*
>> + * For DWC_usb31 controller, once DWC3_DCTL_CSFTRST bit is cleared,
>> + * we must wait at least 50ms before accessing the PHY domain
>> + * (synchronization delay). DWC_usb31 Databook section 1.3.2.
>> + */
>> + if (dwc3_is_usb31(dwc))
>> + mdelay(50);
>
> we don't have any locks held. Why are you busy looping for an entire
> 50ms? Why don't you msleep() here?
>
You're right. I'll make an update.
Thanks,
Thinh
--
To unsubscribe from this list: send the line "unsubscribe linux-usb" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
