On 10/15/2016 8:07 AM, 陈豪 wrote:
> 2016-09-25 2:50 GMT+08:00 Randy Li <ayaka@xxxxxxxxxxx>:
>> On the rk3288 USB host-only port (the one that's not the OTG-enabled
>> port) the PHY can get into a bad state when a wakeup is asserted (not
>> just a wakeup from full system suspend but also a wakeup from
>> autosuspend).
>>
>> We can get the PHY out of its bad state by asserting its "port reset",
>> but unfortunately that seems to assert a reset onto the USB bus so it
>> could confuse things if we don't actually deenumerate / reenumerate the
>> device.
>>
>> We can also get the PHY out of its bad state by fully resetting it using
>> the reset from the CRU (clock reset unit) in chip, which does a more full
>> reset. The CRU-based reset appears to actually cause devices on the bus
>> to be removed and reinserted, which fixes the problem (albeit in a hacky
>> way).
>>
>> It's unfortunate that we need to do a full re-enumeration of devices at
>> wakeup time, but this is better than alternative of letting the bus get
>> wedged.
>>
>> Signed-off-by: Randy Li <ayaka@xxxxxxxxxxx>
>> ---
>> drivers/usb/dwc2/core_intr.c | 11 +++++++++++
>> 1 file changed, 11 insertions(+)
>>
>> diff --git a/drivers/usb/dwc2/core_intr.c b/drivers/usb/dwc2/core_intr.c
>> index d85c5c9..af27edc 100644
>> --- a/drivers/usb/dwc2/core_intr.c
>> +++ b/drivers/usb/dwc2/core_intr.c
>> @@ -345,6 +345,7 @@ static void dwc2_handle_session_req_intr(struct dwc2_hsotg *hsotg)
>> static void dwc2_handle_wakeup_detected_intr(struct dwc2_hsotg *hsotg)
>> {
>> int ret;
>> + struct device_node *np = hsotg->dev->of_node;
>>
>> /* Clear interrupt */
>> dwc2_writel(GINTSTS_WKUPINT, hsotg->regs + GINTSTS);
>> @@ -379,6 +380,16 @@ static void dwc2_handle_wakeup_detected_intr(struct dwc2_hsotg *hsotg)
>> /* Restart the Phy Clock */
>> pcgcctl &= ~PCGCTL_STOPPCLK;
>> dwc2_writel(pcgcctl, hsotg->regs + PCGCTL);
>> +
>> + /*
>> + * It is a quirk in Rockchip RK3288, causing by
>> + * a hardware bug. This will propagate out and
>> + * eventually we'll re-enumerate the device.
>> + * Not great but the best we can do.
>> + */
>> + if (of_device_is_compatible(np, "rockchip,rk3288-usb"))
>> + phy_reset(hsotg->phy);
>
> It will call mutex_lock in phy_reset.
>
>
>> +
>> mod_timer(&hsotg->wkp_timer,
>> jiffies + msecs_to_jiffies(71));
>> } else {
>> --
>> 2.7.4
>>
>
> What is the status of this patch？
> Sleeping calls(phy_reset ==> mutex) shouldn't be used in irq handler.
> Randy will correct that？
>
Yes, that's right, I missed that.
It will have to be fixed.
Regards,
John
--
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
