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Re: [PATCH v3 2/2] phy: rockchip-inno-usb2: correct 480MHz output clock stable time

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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.
>
>
>

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[PATCH v3 0/2] phy: rockchip-inno-usb2: correct 480MHz clk_ops callbacks and stable time William Wu <wulf@rock-chips.com> - 2016-11-14 10:30 +0100
  [PATCH v3 2/2] phy: rockchip-inno-usb2: correct 480MHz output clock stable time William Wu <wulf@rock-chips.com> - 2016-11-14 10:40 +0100
    Re: [PATCH v3 2/2] phy: rockchip-inno-usb2: correct 480MHz output  clock stable time Doug Anderson <dianders@google.com> - 2016-11-14 19:20 +0100
      Re: [PATCH v3 2/2] phy: rockchip-inno-usb2: correct 480MHz output  clock stable time wlf <wulf@rock-chips.com> - 2016-11-15 04:30 +0100
  [PATCH v3 1/2] phy: rockchip-inno-usb2: correct clk_ops callback William Wu <wulf@rock-chips.com> - 2016-11-14 10:40 +0100

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