Re: [PATCH v3 01/15] phy: rockchip-emmc: give DLL some extra time to be ready

Guenter Roeck
2016-06-20T19:23:59Z

On Mon, Jun 20, 2016 at 10:56 AM, Douglas Anderson
<dianders-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org> wrote:
> From: Shawn Lin <shawn.lin-TNX95d0MmH7DzftRWevZcw@public.gmane.org>
>
> According to the databook, 10.2us is the max time for dll to be ready to
> work. However in testing, some chips need 20us for dll to be ready. This

Nitpick, but description (20uS) and code (more than 25 uS) don't match.

> patch adds some extra margin for dllrdy to be ready, fixing our
> -ETIMEDOUT issues.
>
> Signed-off-by: Shawn Lin <shawn.lin-TNX95d0MmH7DzftRWevZcw@public.gmane.org>
> Signed-off-by: Brian Norris <briannorris-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>
> Signed-off-by: Douglas Anderson <dianders-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>
> Acked-by: Kishon Vijay Abraham I <kishon-l0cyMroinI0@public.gmane.org>
> Tested-by: Heiko Stuebner <heiko-4mtYJXux2i+zQB+pC5nmwQ@public.gmane.org>
> ---
> Changes in v3:
> - Add Brian's PHY patches into my series
>
> Changes in v2: None
>
> drivers/phy/phy-rockchip-emmc.c | 7 ++++---
> 1 file changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/phy/phy-rockchip-emmc.c b/drivers/phy/phy-rockchip-emmc.c
> index 6ebcf3e41c46..48cbe691a889 100644
> --- a/drivers/phy/phy-rockchip-emmc.c
> +++ b/drivers/phy/phy-rockchip-emmc.c
> @@ -119,10 +119,11 @@ static int rockchip_emmc_phy_power(struct rockchip_emmc_phy *rk_phy,
> PHYCTRL_ENDLL_MASK,
> PHYCTRL_ENDLL_SHIFT));
> /*
> - * After enable analog DLL circuits, we need extra 10.2us
> - * for dll to be ready for work.
> + * After enable analog DLL circuits, we need an extra 10.2us
> + * for dll to be ready for work. But according to testing, we
> + * find some chips need more than 25us.
> */
> - udelay(11);
> + udelay(30);
> regmap_read(rk_phy->reg_base,
> rk_phy->reg_offset + GRF_EMMCPHY_STATUS,
> &dllrdy);
> --
> 2.8.0.rc3.226.g39d4020
>