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Message-ID: <54AFDEB9.3060402@ti.com>
Date: Fri, 9 Jan 2015 19:29:21 +0530
From: Kishon Vijay Abraham I <kishon@...com>
To: Roger Quadros <rogerq@...com>, <tony@...mide.com>
CC: <nm@...com>, <balbi@...com>, <george.cherian@...com>,
<nsekhar@...com>, <linux-omap@...r.kernel.org>,
<linux-kernel@...r.kernel.org>,
"devicetree@...r.kernel.org" <devicetree@...r.kernel.org>
Subject: Re: [PATCH v2 2/2] phy: ti-pipe3: Fix SATA across suspend/resume
Hi Roger,
On Thursday 08 January 2015 04:47 PM, Roger Quadros wrote:
> Failed test case: Boot without SATA drive connected. Suspend/resume
> the board and then connect SATA drive. It fails to enumerate.
>
> Due to Errata i783 "SATA Lockup After SATA DPLL Unlock/Relock"
> we can't allow SATA DPLL to be in the unlocked state.
> The SATA refclk (sata_ref_clk) is the source of the SATA_DPLL.
> Till now this clock was controlled by the AHCI SATA driver and was being
> shut off during system suspend (if the SATA drive was not already attached)
> causing the SATA DPLL to be unlocked and so causing errata i783.
>
> To prevent sata_ref_clk from being disabled, we move the control of
> this clock from the SATA AHCI driver to the SATA PHY driver and prevent
> it from being disabled.
>
> This also fixes the issue of SATA not working on OMAP5/DRA7 when
> AHCI platform driver is built as a module.
I feel the dt patches and the PHY patches can go separately. Can you split and
re-send?
Thanks
Kishon
>
> Signed-off-by: Roger Quadros <rogerq@...com>
> ---
> v2: don't bail out for missing refclk on SATA phy to work with older broken DTBs.
>
> arch/arm/boot/dts/dra7.dtsi | 4 ++--
> arch/arm/boot/dts/omap5.dtsi | 4 ++--
> drivers/phy/phy-ti-pipe3.c | 57 +++++++++++++++++++++++++++++++-------------
> 3 files changed, 45 insertions(+), 20 deletions(-)
>
> diff --git a/arch/arm/boot/dts/dra7.dtsi b/arch/arm/boot/dts/dra7.dtsi
> index 22771bc..8d2a635 100644
> --- a/arch/arm/boot/dts/dra7.dtsi
> +++ b/arch/arm/boot/dts/dra7.dtsi
> @@ -1090,8 +1090,8 @@
> <0x4A096800 0x40>; /* pll_ctrl */
> reg-names = "phy_rx", "phy_tx", "pll_ctrl";
> ctrl-module = <&omap_control_sata>;
> - clocks = <&sys_clkin1>;
> - clock-names = "sysclk";
> + clocks = <&sys_clkin1>, <&sata_ref_clk>;
> + clock-names = "sysclk", "refclk";
> #phy-cells = <0>;
> };
>
> diff --git a/arch/arm/boot/dts/omap5.dtsi b/arch/arm/boot/dts/omap5.dtsi
> index b321fdf..bb498e7 100644
> --- a/arch/arm/boot/dts/omap5.dtsi
> +++ b/arch/arm/boot/dts/omap5.dtsi
> @@ -929,8 +929,8 @@
> <0x4A096800 0x40>; /* pll_ctrl */
> reg-names = "phy_rx", "phy_tx", "pll_ctrl";
> ctrl-module = <&omap_control_sata>;
> - clocks = <&sys_clkin>;
> - clock-names = "sysclk";
> + clocks = <&sys_clkin>, <&sata_ref_clk>;
> + clock-names = "sysclk", "refclk";
> #phy-cells = <0>;
> };
> };
> diff --git a/drivers/phy/phy-ti-pipe3.c b/drivers/phy/phy-ti-pipe3.c
> index e60ff14..456dec2 100644
> --- a/drivers/phy/phy-ti-pipe3.c
> +++ b/drivers/phy/phy-ti-pipe3.c
> @@ -85,6 +85,7 @@ struct ti_pipe3 {
> struct pipe3_dpll_map *dpll_map;
> u8 id;
> bool enabled;
> + bool refclk_enabled; /* this flag is needed specifically for SATA */
> spinlock_t lock; /* serialize clock enable/disable */
> };
>
> @@ -333,21 +334,24 @@ static int ti_pipe3_probe(struct platform_device *pdev)
> }
> }
>
> + phy->refclk = devm_clk_get(phy->dev, "refclk");
> + if (IS_ERR(phy->refclk)) {
> + dev_err(&pdev->dev, "unable to get refclk\n");
> + /* older DTBs have missing refclk in SATA PHY
> + * so don't bail out in case of SATA PHY.
> + */
> + if (!of_device_is_compatible(node, "ti,phy-pipe3-sata"))
> + return PTR_ERR(phy->refclk);
> + }
> +
> if (!of_device_is_compatible(node, "ti,phy-pipe3-sata")) {
> phy->wkupclk = devm_clk_get(phy->dev, "wkupclk");
> if (IS_ERR(phy->wkupclk)) {
> dev_err(&pdev->dev, "unable to get wkupclk\n");
> return PTR_ERR(phy->wkupclk);
> }
> -
> - phy->refclk = devm_clk_get(phy->dev, "refclk");
> - if (IS_ERR(phy->refclk)) {
> - dev_err(&pdev->dev, "unable to get refclk\n");
> - return PTR_ERR(phy->refclk);
> - }
> } else {
> phy->wkupclk = ERR_PTR(-ENODEV);
> - phy->refclk = ERR_PTR(-ENODEV);
> }
>
> if (of_device_is_compatible(node, "ti,phy-pipe3-pcie")) {
> @@ -428,6 +432,29 @@ static int ti_pipe3_remove(struct platform_device *pdev)
> }
>
> #ifdef CONFIG_PM
> +static int ti_pipe3_enable_refclk(struct ti_pipe3 *phy)
> +{
> + if (!IS_ERR(phy->refclk) && !phy->refclk_enabled) {
> + int ret;
> +
> + ret = clk_prepare_enable(phy->refclk);
> + if (ret) {
> + dev_err(phy->dev, "Failed to enable refclk %d\n", ret);
> + return ret;
> + }
> + phy->refclk_enabled = true;
> + }
> +
> + return 0;
> +}
> +
> +static void ti_pipe3_disable_refclk(struct ti_pipe3 *phy)
> +{
> + if (!IS_ERR(phy->refclk))
> + clk_disable_unprepare(phy->refclk);
> +
> + phy->refclk_enabled = false;
> +}
>
> static int ti_pipe3_enable_clocks(struct ti_pipe3 *phy)
> {
> @@ -438,13 +465,9 @@ static int ti_pipe3_enable_clocks(struct ti_pipe3 *phy)
> if (phy->enabled)
> goto err1;
>
> - if (!IS_ERR(phy->refclk)) {
> - ret = clk_prepare_enable(phy->refclk);
> - if (ret) {
> - dev_err(phy->dev, "Failed to enable refclk %d\n", ret);
> - goto err1;
> - }
> - }
> + ret = ti_pipe3_enable_refclk(phy);
> + if (ret)
> + goto err1;
>
> if (!IS_ERR(phy->wkupclk)) {
> ret = clk_prepare_enable(phy->wkupclk);
> @@ -474,6 +497,7 @@ err2:
> if (!IS_ERR(phy->refclk))
> clk_disable_unprepare(phy->refclk);
>
> + ti_pipe3_disable_refclk(phy);
> err1:
> spin_unlock_irqrestore(&phy->lock, flags);
> return ret;
> @@ -491,8 +515,9 @@ static void ti_pipe3_disable_clocks(struct ti_pipe3 *phy)
>
> if (!IS_ERR(phy->wkupclk))
> clk_disable_unprepare(phy->wkupclk);
> - if (!IS_ERR(phy->refclk))
> - clk_disable_unprepare(phy->refclk);
> + /* Don't disable refclk for SATA PHY due to Errata i783 */
> + if (!of_device_is_compatible(phy->dev->of_node, "ti,phy-pipe3-sata"))
> + ti_pipe3_disable_refclk(phy);
> if (!IS_ERR(phy->div_clk))
> clk_disable_unprepare(phy->div_clk);
> phy->enabled = false;
>
--
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