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Date: Wed, 20 May 2015 18:34:17 +0530
From: Kishon Vijay Abraham I <kishon@...com>
To: Roger Quadros <rogerq@...com>, <tony@...mide.com>
CC: <nm@...com>, <nsekhar@...com>, <balbi@...com>,
<grygorii.strashko@...com>, <linux-kernel@...r.kernel.org>,
<linux-omap@...r.kernel.org>
Subject: Re: [PATCH 1/3] phy: ti-pipe3: fix suspend
Hi Roger,
On Tuesday 12 May 2015 09:37 PM, Roger Quadros wrote:
> Relying on PM-ops for shutting down PHY clocks was a
> bad idea since the users (e.g. PCIe/SATA) might not
> have been suspended by then.
>
> The main culprit for not shutting down the clocks was
> the stray pm_runtime_get() call in probe.
>
> Fix the whole thing in the right way by getting rid
> of that pm_runtime_get() call from probe and
> removing all PM-ops. It is the sole responsibility
> of the PHY user to properly turn OFF and de-initialize
> the PHY as part of its suspend routine.
>
> As PHY core serializes init/exit we don't need
> to use a spinlock in this driver. So get rid of it.
>
> Signed-off-by: Roger Quadros <rogerq@...com>
> Signed-off-by: Sekhar Nori <nsekhar@...com>
> ---
> drivers/phy/phy-ti-pipe3.c | 112 ++++++++-------------------------------------
> 1 file changed, 18 insertions(+), 94 deletions(-)
>
> diff --git a/drivers/phy/phy-ti-pipe3.c b/drivers/phy/phy-ti-pipe3.c
> index 53f295c..e13a306 100644
> --- a/drivers/phy/phy-ti-pipe3.c
> +++ b/drivers/phy/phy-ti-pipe3.c
> @@ -28,7 +28,6 @@
> #include <linux/delay.h>
> #include <linux/phy/omap_control_phy.h>
> #include <linux/of_platform.h>
> -#include <linux/spinlock.h>
>
> #define PLL_STATUS 0x00000004
> #define PLL_GO 0x00000008
> @@ -83,10 +82,6 @@ struct ti_pipe3 {
> struct clk *refclk;
> struct clk *div_clk;
> struct pipe3_dpll_map *dpll_map;
> - bool enabled;
> - spinlock_t lock; /* serialize clock enable/disable */
> - /* the below flag is needed specifically for SATA */
> - bool refclk_enabled;
> };
>
> static struct pipe3_dpll_map dpll_map_usb[] = {
> @@ -137,6 +132,9 @@ static struct pipe3_dpll_params *ti_pipe3_get_dpll_params(struct ti_pipe3 *phy)
> return NULL;
> }
>
> +static int ti_pipe3_enable_clocks(struct ti_pipe3 *phy);
> +static void ti_pipe3_disable_clocks(struct ti_pipe3 *phy);
> +
> static int ti_pipe3_power_off(struct phy *x)
> {
> struct ti_pipe3 *phy = phy_get_drvdata(x);
> @@ -217,6 +215,7 @@ static int ti_pipe3_init(struct phy *x)
> u32 val;
> int ret = 0;
>
> + ti_pipe3_enable_clocks(phy);
> /*
> * Set pcie_pcs register to 0x96 for proper functioning of phy
> * as recommended in AM572x TRM SPRUHZ6, section 18.5.2.2, table
> @@ -277,6 +276,8 @@ static int ti_pipe3_exit(struct phy *x)
> return -EBUSY;
> }
>
> + ti_pipe3_disable_clocks(phy);
> +
> return 0;
> }
> static struct phy_ops ops = {
> @@ -305,8 +306,7 @@ static int ti_pipe3_probe(struct platform_device *pdev)
> if (!phy)
> return -ENOMEM;
>
> - phy->dev = &pdev->dev;
> - spin_lock_init(&phy->lock);
> + phy->dev = &pdev->dev;
this looks more of a cleanup.
>
> if (!of_device_is_compatible(node, "ti,phy-pipe3-pcie")) {
> match = of_match_device(ti_pipe3_id_table, &pdev->dev);
> @@ -402,6 +402,9 @@ static int ti_pipe3_probe(struct platform_device *pdev)
>
> platform_set_drvdata(pdev, phy);
> pm_runtime_enable(phy->dev);
> + /* Prevent auto-disable of refclk for SATA PHY due to Errata i783 */
> + if (of_device_is_compatible(node, "ti,phy-pipe3-sata"))
> + clk_prepare_enable(phy->refclk);
>
> generic_phy = devm_phy_create(phy->dev, NULL, &ops);
> if (IS_ERR(generic_phy))
> @@ -413,24 +416,19 @@ static int ti_pipe3_probe(struct platform_device *pdev)
> if (IS_ERR(phy_provider))
> return PTR_ERR(phy_provider);
>
> - pm_runtime_get(&pdev->dev);
> -
> return 0;
> }
>
> static int ti_pipe3_remove(struct platform_device *pdev)
> {
> - if (!pm_runtime_suspended(&pdev->dev))
> - pm_runtime_put(&pdev->dev);
> pm_runtime_disable(&pdev->dev);
>
> return 0;
> }
>
> -#ifdef CONFIG_PM
> static int ti_pipe3_enable_refclk(struct ti_pipe3 *phy)
> {
> - if (!IS_ERR(phy->refclk) && !phy->refclk_enabled) {
> + if (!IS_ERR(phy->refclk)) {
> int ret;
>
> ret = clk_prepare_enable(phy->refclk);
> @@ -438,7 +436,6 @@ static int ti_pipe3_enable_refclk(struct ti_pipe3 *phy)
> dev_err(phy->dev, "Failed to enable refclk %d\n", ret);
> return ret;
> }
> - phy->refclk_enabled = true;
> }
>
> return 0;
> @@ -448,28 +445,21 @@ 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)
> {
> int ret = 0;
> - unsigned long flags;
> -
> - spin_lock_irqsave(&phy->lock, flags);
> - if (phy->enabled)
> - goto err1;
>
> ret = ti_pipe3_enable_refclk(phy);
we can enable refclk here itself instead of having a separate function it?
> if (ret)
> - goto err1;
> + return ret;
>
> if (!IS_ERR(phy->wkupclk)) {
> ret = clk_prepare_enable(phy->wkupclk);
> if (ret) {
> dev_err(phy->dev, "Failed to enable wkupclk %d\n", ret);
> - goto err2;
> + goto disable_refclk;
> }
> }
>
> @@ -477,96 +467,31 @@ static int ti_pipe3_enable_clocks(struct ti_pipe3 *phy)
> ret = clk_prepare_enable(phy->div_clk);
> if (ret) {
> dev_err(phy->dev, "Failed to enable div_clk %d\n", ret);
> - goto err3;
> + goto disable_wkupclk;
> }
> }
>
> - phy->enabled = true;
> - spin_unlock_irqrestore(&phy->lock, flags);
> return 0;
>
> -err3:
> +disable_wkupclk:
> if (!IS_ERR(phy->wkupclk))
> clk_disable_unprepare(phy->wkupclk);
>
> -err2:
> - if (!IS_ERR(phy->refclk))
> - clk_disable_unprepare(phy->refclk);
> -
> +disable_refclk:
> ti_pipe3_disable_refclk(phy);
> -err1:
> - spin_unlock_irqrestore(&phy->lock, flags);
> +
> return ret;
> }
>
> static void ti_pipe3_disable_clocks(struct ti_pipe3 *phy)
> {
> - unsigned long flags;
> -
> - spin_lock_irqsave(&phy->lock, flags);
> - if (!phy->enabled) {
> - spin_unlock_irqrestore(&phy->lock, flags);
> - return;
> - }
> -
> if (!IS_ERR(phy->wkupclk))
> clk_disable_unprepare(phy->wkupclk);
> - /* 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);
> + ti_pipe3_disable_refclk(phy);
here too. we can get rid of ti_pipe3_disable_refclk and ti_pipe3_enable_refclk.
Thanks
Kishon
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