[PATCH v3 2/2] phy: rockchip-inno-usb2: correct 480MHz output clock stable time
dianders at google.com
Mon Nov 14 10:17:03 PST 2016
On Mon, Nov 14, 2016 at 1:27 AM, William Wu <wulf at 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 at 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 at chromium.org>
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