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Date: Wed, 20 May 2015 16:48:31 +0300
From: Roger Quadros <rogerq@...com>
To: Kishon Vijay Abraham I <kishon@...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
Kishon,
On 20/05/15 16:04, Kishon Vijay Abraham I wrote:
> 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.
ok will get rid of it.
>>
>> 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.
>
fine.
cheers,
-roger
--
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