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Message-ID: <5767EB7E.3040606@ti.com>
Date: Mon, 20 Jun 2016 18:41:26 +0530
From: Kishon Vijay Abraham I <kishon@...com>
To: Brian Norris <briannorris@...omium.org>
CC: Heiko Stuebner <heiko@...ech.de>, <linux-kernel@...r.kernel.org>,
<linux-rockchip@...ts.infradead.org>,
Doug Anderson <dianders@...omium.org>,
Shawn Lin <shawn.lin@...k-chips.com>,
<linux-arm-kernel@...ts.infradead.org>,
Brian Norris <computersforpeace@...il.com>
Subject: Re: [PATCH 1/4] phy: rockchip-emmc: give DLL some extra time to be
ready
On Friday 13 May 2016 04:13 AM, Brian Norris wrote:
> From: Shawn Lin <shawn.lin@...k-chips.com>
>
> 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
> patch adds some extra margin for dllrdy to be ready, fixing our
> -ETIMEDOUT issues.
>
> Signed-off-by: Shawn Lin <shawn.lin@...k-chips.com>
> Signed-off-by: Brian Norris <briannorris@...omium.org>
Acked-by: Kishon Vijay Abraham I <kishon@...com>
> ---
> 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);
>
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