diff mbox

clk: ti: omap3+: dpll: use non-locking version of clk_get_rate

Message ID 1453981067-8618-1-git-send-email-t-kristo@ti.com
State Superseded
Headers show

Commit Message

Tero Kristo Jan. 28, 2016, 11:37 a.m. UTC
As the code in this file is being executed within irq context in some
cases, we must avoid the clk_get_rate which uses mutex internally.
Switch the code to use clk_hw_get_rate instead which is non-locking.

Signed-off-by: Tero Kristo <t-kristo@ti.com>

---
 drivers/clk/ti/dpll3xxx.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

-- 
1.7.9.5

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Comments

Tero Kristo Jan. 28, 2016, 11:43 a.m. UTC | #1
On 01/28/2016 01:37 PM, Tero Kristo wrote:
> As the code in this file is being executed within irq context in some

> cases, we must avoid the clk_get_rate which uses mutex internally.

> Switch the code to use clk_hw_get_rate instead which is non-locking.

>

> Signed-off-by: Tero Kristo <t-kristo@ti.com>


Ooops, sorry. Sent wrong version (read: old) of this patch, please 
ignore this one. Will re-send the correct version in a bit.

-Tero

> ---

>   drivers/clk/ti/dpll3xxx.c |    3 ++-

>   1 file changed, 2 insertions(+), 1 deletion(-)

>

> diff --git a/drivers/clk/ti/dpll3xxx.c b/drivers/clk/ti/dpll3xxx.c

> index f4dec00..7ed24bc 100644

> --- a/drivers/clk/ti/dpll3xxx.c

> +++ b/drivers/clk/ti/dpll3xxx.c

> @@ -437,7 +437,8 @@ int omap3_noncore_dpll_enable(struct clk_hw *hw)

>

>   	parent = clk_hw_get_parent(hw);

>

> -	if (clk_hw_get_rate(hw) == clk_get_rate(dd->clk_bypass)) {

> +	if (clk_hw_get_rate(hw) ==

> +	    clk_hw_get_rate(__clk_get_hw(dd->clk_bypass))) {

>   		WARN_ON(parent != __clk_get_hw(dd->clk_bypass));

>   		r = _omap3_noncore_dpll_bypass(clk);

>   	} else {

>


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Tero Kristo Jan. 28, 2016, 6:48 p.m. UTC | #2
On 01/28/2016 07:22 PM, Tony Lindgren wrote:
> * Tero Kristo <t-kristo@ti.com> [160128 03:44]:

>> On 01/28/2016 01:37 PM, Tero Kristo wrote:

>>> As the code in this file is being executed within irq context in some

>>> cases, we must avoid the clk_get_rate which uses mutex internally.

>>> Switch the code to use clk_hw_get_rate instead which is non-locking.

>>>

>>> Signed-off-by: Tero Kristo <t-kristo@ti.com>

>>

>> Ooops, sorry. Sent wrong version (read: old) of this patch, please ignore

>> this one. Will re-send the correct version in a bit.

>

> I think this is still needed as a fix for -rc cycle with cc: stable

> as otherwise we have omap4 and 5 hang if PM runtime is enabled before

> a suspend/resume cycle?


Look at the other patch I sent, it should accomplish the same thing, and 
more.

https://www.spinics.net/lists/linux-clk/msg06094.html

-Tero

>

> Regards,

>

> Tony

>

>

>>>   drivers/clk/ti/dpll3xxx.c |    3 ++-

>>>   1 file changed, 2 insertions(+), 1 deletion(-)

>>>

>>> diff --git a/drivers/clk/ti/dpll3xxx.c b/drivers/clk/ti/dpll3xxx.c

>>> index f4dec00..7ed24bc 100644

>>> --- a/drivers/clk/ti/dpll3xxx.c

>>> +++ b/drivers/clk/ti/dpll3xxx.c

>>> @@ -437,7 +437,8 @@ int omap3_noncore_dpll_enable(struct clk_hw *hw)

>>>

>>>   	parent = clk_hw_get_parent(hw);

>>>

>>> -	if (clk_hw_get_rate(hw) == clk_get_rate(dd->clk_bypass)) {

>>> +	if (clk_hw_get_rate(hw) ==

>>> +	    clk_hw_get_rate(__clk_get_hw(dd->clk_bypass))) {

>>>   		WARN_ON(parent != __clk_get_hw(dd->clk_bypass));

>>>   		r = _omap3_noncore_dpll_bypass(clk);

>>>   	} else {

>>>

>>


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Tero Kristo Jan. 28, 2016, 7:09 p.m. UTC | #3
On 01/28/2016 09:00 PM, Tony Lindgren wrote:
> * Tero Kristo <t-kristo@ti.com> [160128 10:48]:

>> On 01/28/2016 07:22 PM, Tony Lindgren wrote:

>>> * Tero Kristo <t-kristo@ti.com> [160128 03:44]:

>>>> On 01/28/2016 01:37 PM, Tero Kristo wrote:

>>>>> As the code in this file is being executed within irq context in some

>>>>> cases, we must avoid the clk_get_rate which uses mutex internally.

>>>>> Switch the code to use clk_hw_get_rate instead which is non-locking.

>>>>>

>>>>> Signed-off-by: Tero Kristo <t-kristo@ti.com>

>>>>

>>>> Ooops, sorry. Sent wrong version (read: old) of this patch, please ignore

>>>> this one. Will re-send the correct version in a bit.

>>>

>>> I think this is still needed as a fix for -rc cycle with cc: stable

>>> as otherwise we have omap4 and 5 hang if PM runtime is enabled before

>>> a suspend/resume cycle?

>>

>> Look at the other patch I sent, it should accomplish the same thing, and

>> more.

>>

>> https://www.spinics.net/lists/linux-clk/msg06094.html

>

> Right.. But is that suitable for the -rc cycle with cc stable?


Hmm yea, thats a good question, we may need to resurrect this patch 
after all.

> You should also describe the bug it causes in the change log.

> Something like:

>

> This fixes an issue where PM runtime will hang the system if

> enabled with a serial console before a suspend-resume cycle.


Yea I can add this to the desc if we want to keep this version of the patch.

-Tero


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diff mbox

Patch

diff --git a/drivers/clk/ti/dpll3xxx.c b/drivers/clk/ti/dpll3xxx.c
index f4dec00..7ed24bc 100644
--- a/drivers/clk/ti/dpll3xxx.c
+++ b/drivers/clk/ti/dpll3xxx.c
@@ -437,7 +437,8 @@  int omap3_noncore_dpll_enable(struct clk_hw *hw)
 
 	parent = clk_hw_get_parent(hw);
 
-	if (clk_hw_get_rate(hw) == clk_get_rate(dd->clk_bypass)) {
+	if (clk_hw_get_rate(hw) ==
+	    clk_hw_get_rate(__clk_get_hw(dd->clk_bypass))) {
 		WARN_ON(parent != __clk_get_hw(dd->clk_bypass));
 		r = _omap3_noncore_dpll_bypass(clk);
 	} else {