Hello. On 09/09/2016 09:59 PM, Randy Li wrote:
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
[...]
@@ -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
Caused. [...] MBR, Sergei -- 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
