| Message ID | 1479115631-20137-3-git-send-email-wulf@rock-chips.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
William, On Mon, Nov 14, 2016 at 1:27 AM, William Wu <wulf@rock-chips.com> 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@rock-chips.com> > --- > 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@chromium.org>
Hi Doug, 在 2016年11月15日 02:17, Doug Anderson 写道: > William, > > On Mon, Nov 14, 2016 at 1:27 AM, William Wu <wulf@rock-chips.com> 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@rock-chips.com> >> --- >> 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@chromium.org> Thanks! I'll add Reviewed-by and fix the spelling issue. > > >
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); } return 0;
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@rock-chips.com> --- 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(-)