William, On Mon, Nov 14, 2016 at 1:27 AM, William Wu <wulf@xxxxxxxxxxxxxx> wrote: > We found that the system crashed due to 480MHz output clock of > USB2 PHY was unstable after clock had been enabled by gpu module. > > Theoretically, 1 millisecond is a critical value for 480MHz > output clock stable time, so we try to change the delay time > to 1.2 millisecond to avoid this issue. > > And the commit ed907fb1d7c3 ("phy: rockchip-inno-usb2: correct > clk_ops callback") used prepare callbacks instead of enable > callbacks to support gate a clk if the operation may sleep. So > we can switch from delay to sleep functions. > > Signed-off-by: William Wu <wulf@xxxxxxxxxxxxxx> > --- > Changes in v3: > - fix kbuild test error: too few arguments to function 'usleep_range' > > Changes in v2: > - use usleep_range() function instead of mdelay() > > drivers/phy/phy-rockchip-inno-usb2.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/phy/phy-rockchip-inno-usb2.c b/drivers/phy/phy-rockchip-inno-usb2.c > index 365e077..0e52b25 100644 > --- a/drivers/phy/phy-rockchip-inno-usb2.c > +++ b/drivers/phy/phy-rockchip-inno-usb2.c > @@ -166,7 +166,7 @@ static int rockchip_usb2phy_clk480m_prepare(struct clk_hw *hw) > return ret; > > /* waitting for the clk become stable */ > - mdelay(1); > + usleep_range(1200, 1300); Sight nit that you could also fix the spelling from "waitting" to "waiting". ...but that's pre-existing, so: Reviewed-by: Douglas Anderson <dianders@xxxxxxxxxxxx> -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html