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@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>
Thanks! I'll add Reviewed-by and fix the spelling issue.
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