Hi Maintainner, Could you please share your thoughts with me? Thanks a lot. -----邮件原件----- 发件人: Fang, Yuan 发送时间: 2021年6月16日 10:56 收件人: 'Felipe Balbi'; Yuan Fang; linux-usb@xxxxxxxxxxxxxxx 主题: 答复: [PATCH] drivers/usb/dwc3: Set PHY ready after soft reset done Hi Balbi, > It's more safe to set PHY ready after soft reset done > > Let's consider a test case like this: > I have a usb PHY which don't need SW initial before access it, But i > have a wrong PHY clock default setting in PHY register which means PHY > is not ready in fact. > in dwc3_core_init, dwc3_core_get_phy will return 0 despite usb get > PHYs with return -ENODEV, and set phys_ready=true > your PHY driver shouldn't return -ENODEV here. Why are you returning -ENODEV? The PHY isn't ready but it _does_ exist. Sorry for the late reply, my explain may be not clear, let me describe it once more 1, I don’t coding a PHY driver, I have a PHY which do NOT need SW operation All I should do is set the related PHY ctrl regs correctly. So I do not return anything to generic PHY framework. 2, In my above case, dwc3_core_get_phy will return 0, and set dwc->phys_ready=true, And then, dwc3_core_soft_reset will cost retries*20ms to check if soft-reset is done , and return -ETIMEDOUT if time out, is that correct? My point is, in this case(PHY do not set correctly, which is not rare during development stage I think), PHY initial fail led to soft-reset timeout but dwc->phys_ready is true, So I think is more safe to say "PHY is ready" after soft-reset done, please let me know your opinion, thanks a lot Yuan Fang -----邮件原件----- 发件人: Felipe Balbi [mailto:balbi@xxxxxxxxxx] 发送时间: 2021年6月11日 21:03 收件人: Yuan Fang; linux-usb@xxxxxxxxxxxxxxx 抄送: Fang, Yuan 主题: Re: [PATCH] drivers/usb/dwc3: Set PHY ready after soft reset done Yuan Fang <fangyuanseu@xxxxxxxxx> writes: > It's more safe to set PHY ready after soft reset done > > Let's consider a test case like this: > I have a usb PHY which don't need SW initial before access it, But i > have a wrong PHY clock default setting in PHY register which means PHY > is not ready in fact. > in dwc3_core_init, dwc3_core_get_phy will return 0 despite usb get > PHYs with return -ENODEV, and set phys_ready=true your PHY driver shouldn't return -ENODEV here. Why are you returning -ENODEV? The PHY isn't ready but it _does_ exist. -- balbi
