diff mbox

[v5] ARM: davinci: da8xx: Fix sleeping function called from invalid context

Message ID 1480947224-26222-1-git-send-email-abailon@baylibre.com
State Superseded
Headers show

Commit Message

Alexandre Bailon Dec. 5, 2016, 2:13 p.m. UTC
Everytime the usb20 phy is enabled, there is a
"sleeping function called from invalid context" BUG.

clk_enable() from arch/arm/mach-davinci/clock.c uses spin_lock_irqsave()
before to invoke the callback usb20_phy_clk_enable().
usb20_phy_clk_enable() uses clk_get() and clk_enable_prepapre()
which may sleep.
Move clk_get() to da8xx_register_usb20_phy_clk() and
replace clk_prepare_enable() by clk_enable().

Signed-off-by: Alexandre Bailon <abailon@baylibre.com>

---
 arch/arm/mach-davinci/usb-da8xx.c | 29 +++++++++++++++--------------
 1 file changed, 15 insertions(+), 14 deletions(-)

-- 
2.7.3


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Comments

Sekhar Nori Dec. 6, 2016, 9:33 a.m. UTC | #1
On Monday 05 December 2016 07:43 PM, Alexandre Bailon wrote:
> Everytime the usb20 phy is enabled, there is a

> "sleeping function called from invalid context" BUG.

> 

> clk_enable() from arch/arm/mach-davinci/clock.c uses spin_lock_irqsave()

> before to invoke the callback usb20_phy_clk_enable().

> usb20_phy_clk_enable() uses clk_get() and clk_enable_prepapre()

> which may sleep.

> Move clk_get() to da8xx_register_usb20_phy_clk() and

> replace clk_prepare_enable() by clk_enable().

> 

> Signed-off-by: Alexandre Bailon <abailon@baylibre.com>


This will still cause the recursive locking problem reported by David.
Not sure what the point of sending this version was.

Thanks,
Sekhar


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Alexandre Bailon Dec. 6, 2016, 9:51 a.m. UTC | #2
On 12/06/2016 10:33 AM, Sekhar Nori wrote:
> On Monday 05 December 2016 07:43 PM, Alexandre Bailon wrote:

>> Everytime the usb20 phy is enabled, there is a

>> "sleeping function called from invalid context" BUG.

>>

>> clk_enable() from arch/arm/mach-davinci/clock.c uses spin_lock_irqsave()

>> before to invoke the callback usb20_phy_clk_enable().

>> usb20_phy_clk_enable() uses clk_get() and clk_enable_prepapre()

>> which may sleep.

>> Move clk_get() to da8xx_register_usb20_phy_clk() and

>> replace clk_prepare_enable() by clk_enable().

>>

>> Signed-off-by: Alexandre Bailon <abailon@baylibre.com>

> 

> This will still cause the recursive locking problem reported by David.

> Not sure what the point of sending this version was.

> 

> Thanks,

> Sekhar

> 

What am I supposed to do ?

Thanks,
Alexandre

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Sekhar Nori Dec. 6, 2016, 9:57 a.m. UTC | #3
On Tuesday 06 December 2016 03:21 PM, Alexandre Bailon wrote:
> On 12/06/2016 10:33 AM, Sekhar Nori wrote:

>> On Monday 05 December 2016 07:43 PM, Alexandre Bailon wrote:

>>> Everytime the usb20 phy is enabled, there is a

>>> "sleeping function called from invalid context" BUG.

>>>

>>> clk_enable() from arch/arm/mach-davinci/clock.c uses spin_lock_irqsave()

>>> before to invoke the callback usb20_phy_clk_enable().

>>> usb20_phy_clk_enable() uses clk_get() and clk_enable_prepapre()

>>> which may sleep.

>>> Move clk_get() to da8xx_register_usb20_phy_clk() and

>>> replace clk_prepare_enable() by clk_enable().

>>>

>>> Signed-off-by: Alexandre Bailon <abailon@baylibre.com>

>>

>> This will still cause the recursive locking problem reported by David.

>> Not sure what the point of sending this version was.

>>

>> Thanks,

>> Sekhar

>>


> What am I supposed to do ?


That needs to be resolved between you and David. Perhaps convert the fix
sent by David into a proper patch and base this patch on that. Or wait
for David to send it himself and let him also make the modifications
needed in this patch.

David ?

Thanks,
Sekhar

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David Lechner Dec. 6, 2016, 6:56 p.m. UTC | #4
On 12/06/2016 03:57 AM, Sekhar Nori wrote:
> On Tuesday 06 December 2016 03:21 PM, Alexandre Bailon wrote:

>> On 12/06/2016 10:33 AM, Sekhar Nori wrote:

>>> On Monday 05 December 2016 07:43 PM, Alexandre Bailon wrote:

>>>> Everytime the usb20 phy is enabled, there is a

>>>> "sleeping function called from invalid context" BUG.

>>>>

>>>> clk_enable() from arch/arm/mach-davinci/clock.c uses spin_lock_irqsave()

>>>> before to invoke the callback usb20_phy_clk_enable().

>>>> usb20_phy_clk_enable() uses clk_get() and clk_enable_prepapre()

>>>> which may sleep.

>>>> Move clk_get() to da8xx_register_usb20_phy_clk() and

>>>> replace clk_prepare_enable() by clk_enable().

>>>>

>>>> Signed-off-by: Alexandre Bailon <abailon@baylibre.com>

>>>

>>> This will still cause the recursive locking problem reported by David.

>>> Not sure what the point of sending this version was.

>>>

>>> Thanks,

>>> Sekhar

>>>

>

>> What am I supposed to do ?

>

> That needs to be resolved between you and David. Perhaps convert the fix

> sent by David into a proper patch and base this patch on that. Or wait

> for David to send it himself and let him also make the modifications

> needed in this patch.

>

> David ?

>

> Thanks,

> Sekhar

>


Alexandre, I was hoping that you would just squash my patch with your 
patch and take Sekhar's suggestion about a separate patch to make the 
private __clk_enable() public as davinci_clk_enable() when you re-submit.

You can add "Suggested-By: David Lechner <david@lechnology.com>" to the 
commit message if you would like to give me some credit for my ideas.

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Alexandre Bailon Dec. 7, 2016, 9:07 a.m. UTC | #5
On 12/06/2016 07:56 PM, David Lechner wrote:
> On 12/06/2016 03:57 AM, Sekhar Nori wrote:

>> On Tuesday 06 December 2016 03:21 PM, Alexandre Bailon wrote:

>>> On 12/06/2016 10:33 AM, Sekhar Nori wrote:

>>>> On Monday 05 December 2016 07:43 PM, Alexandre Bailon wrote:

>>>>> Everytime the usb20 phy is enabled, there is a

>>>>> "sleeping function called from invalid context" BUG.

>>>>>

>>>>> clk_enable() from arch/arm/mach-davinci/clock.c uses

>>>>> spin_lock_irqsave()

>>>>> before to invoke the callback usb20_phy_clk_enable().

>>>>> usb20_phy_clk_enable() uses clk_get() and clk_enable_prepapre()

>>>>> which may sleep.

>>>>> Move clk_get() to da8xx_register_usb20_phy_clk() and

>>>>> replace clk_prepare_enable() by clk_enable().

>>>>>

>>>>> Signed-off-by: Alexandre Bailon <abailon@baylibre.com>

>>>>

>>>> This will still cause the recursive locking problem reported by David.

>>>> Not sure what the point of sending this version was.

>>>>

>>>> Thanks,

>>>> Sekhar

>>>>

>>

>>> What am I supposed to do ?

>>

>> That needs to be resolved between you and David. Perhaps convert the fix

>> sent by David into a proper patch and base this patch on that. Or wait

>> for David to send it himself and let him also make the modifications

>> needed in this patch.

>>

>> David ?

>>

>> Thanks,

>> Sekhar

>>

> 

> Alexandre, I was hoping that you would just squash my patch with your

> patch and take Sekhar's suggestion about a separate patch to make the

> private __clk_enable() public as davinci_clk_enable() when you re-submit.

OK.
> 

> You can add "Suggested-By: David Lechner <david@lechnology.com>" to the

> commit message if you would like to give me some credit for my ideas.

That was my concern. I will do that.

Thanks,
Alexandre

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diff mbox

Patch

diff --git a/arch/arm/mach-davinci/usb-da8xx.c b/arch/arm/mach-davinci/usb-da8xx.c
index b010e5f..f62f9c2 100644
--- a/arch/arm/mach-davinci/usb-da8xx.c
+++ b/arch/arm/mach-davinci/usb-da8xx.c
@@ -22,6 +22,8 @@ 
 #define DA8XX_USB0_BASE		0x01e00000
 #define DA8XX_USB1_BASE		0x01e25000
 
+static struct clk *usb20_clk;
+
 static struct platform_device da8xx_usb_phy = {
 	.name		= "da8xx-usb-phy",
 	.id		= -1,
@@ -158,24 +160,16 @@  int __init da8xx_register_usb_refclkin(int rate)
 
 static void usb20_phy_clk_enable(struct clk *clk)
 {
-	struct clk *usb20_clk;
 	int err;
 	u32 val;
 	u32 timeout = 500000; /* 500 msec */
 
 	val = readl(DA8XX_SYSCFG0_VIRT(DA8XX_CFGCHIP2_REG));
 
-	usb20_clk = clk_get(&da8xx_usb20_dev.dev, "usb20");
-	if (IS_ERR(usb20_clk)) {
-		pr_err("could not get usb20 clk: %ld\n", PTR_ERR(usb20_clk));
-		return;
-	}
-
 	/* The USB 2.O PLL requires that the USB 2.O PSC is enabled as well. */
-	err = clk_prepare_enable(usb20_clk);
+	err = clk_enable(usb20_clk);
 	if (err) {
 		pr_err("failed to enable usb20 clk: %d\n", err);
-		clk_put(usb20_clk);
 		return;
 	}
 
@@ -197,8 +191,7 @@  static void usb20_phy_clk_enable(struct clk *clk)
 
 	pr_err("Timeout waiting for USB 2.0 PHY clock good\n");
 done:
-	clk_disable_unprepare(usb20_clk);
-	clk_put(usb20_clk);
+	clk_disable(usb20_clk);
 }
 
 static void usb20_phy_clk_disable(struct clk *clk)
@@ -285,11 +278,19 @@  static struct clk_lookup usb20_phy_clk_lookup =
 int __init da8xx_register_usb20_phy_clk(bool use_usb_refclkin)
 {
 	struct clk *parent;
-	int ret = 0;
+	int ret;
+
+	usb20_clk = clk_get(&da8xx_usb20_dev.dev, "usb20");
+	ret = PTR_ERR_OR_ZERO(usb20_clk);
+	if (ret)
+		return ret;
 
 	parent = clk_get(NULL, use_usb_refclkin ? "usb_refclkin" : "pll0_aux");
-	if (IS_ERR(parent))
-		return PTR_ERR(parent);
+	ret = PTR_ERR_OR_ZERO(parent);
+	if (ret) {
+		clk_put(usb20_clk);
+		return ret;
+	}
 
 	usb20_phy_clk.parent = parent;
 	ret = clk_register(&usb20_phy_clk);