drm/bridge: analogix dp: Fix runtime PM state on driver bind

Message ID 1483091866-1088-1-git-send-email-m.szyprowski@samsung.com
State New
Headers show

Commit Message

Marek Szyprowski Dec. 30, 2016, 9:57 a.m.
Analogix_dp_bind() can be called from component framework, which doesn't
guarantee proper runtime PM state of the device during bind operation,
so ensure that device is runtime active before doing any register access.
This ensures that the power domain, to which DP module belongs, is turned
on. While at it, also fix the unbalanced call to phy_power_on() in
analogix_dp_bind() function.

This patch solves the following kernel oops on Samsung Exynos5250 Snow
board:

Unhandled fault: imprecise external abort (0x406) at 0x00000000
pgd = c0004000
[00000000] *pgd=00000000
Internal error: : 406 [#1] PREEMPT SMP ARM
Modules linked in:
CPU: 0 PID: 75 Comm: kworker/0:2 Not tainted 4.9.0 #1046
Hardware name: SAMSUNG EXYNOS (Flattened Device Tree)
Workqueue: events deferred_probe_work_func
task: ee272300 task.stack: ee312000
PC is at analogix_dp_enable_sw_function+0x18/0x2c
LR is at analogix_dp_init_dp+0x2c/0x50
...
[<c03fcb38>] (analogix_dp_enable_sw_function) from [<c03fa9c4>] (analogix_dp_init_dp+0x2c/0x50)
[<c03fa9c4>] (analogix_dp_init_dp) from [<c03fab6c>] (analogix_dp_bind+0x184/0x42c)
[<c03fab6c>] (analogix_dp_bind) from [<c03fdb84>] (component_bind_all+0xf0/0x218)
[<c03fdb84>] (component_bind_all) from [<c03ed64c>] (exynos_drm_load+0x134/0x200)
[<c03ed64c>] (exynos_drm_load) from [<c03d5058>] (drm_dev_register+0xa0/0xd0)
[<c03d5058>] (drm_dev_register) from [<c03d66b8>] (drm_platform_init+0x58/0xb0)
[<c03d66b8>] (drm_platform_init) from [<c03fe0c4>] (try_to_bring_up_master+0x14c/0x188)
[<c03fe0c4>] (try_to_bring_up_master) from [<c03fe188>] (component_add+0x88/0x138)
[<c03fe188>] (component_add) from [<c0403a38>] (platform_drv_probe+0x50/0xb0)
[<c0403a38>] (platform_drv_probe) from [<c0402470>] (driver_probe_device+0x1f0/0x2a8)
[<c0402470>] (driver_probe_device) from [<c0400a54>] (bus_for_each_drv+0x44/0x8c)
[<c0400a54>] (bus_for_each_drv) from [<c04021f8>] (__device_attach+0x9c/0x100)
[<c04021f8>] (__device_attach) from [<c04018e8>] (bus_probe_device+0x84/0x8c)
[<c04018e8>] (bus_probe_device) from [<c0401d1c>] (deferred_probe_work_func+0x60/0x8c)
[<c0401d1c>] (deferred_probe_work_func) from [<c012fc14>] (process_one_work+0x120/0x318)
[<c012fc14>] (process_one_work) from [<c012fe34>] (process_scheduled_works+0x28/0x38)
[<c012fe34>] (process_scheduled_works) from [<c0130048>] (worker_thread+0x204/0x4ac)
[<c0130048>] (worker_thread) from [<c01352c4>] (kthread+0xd8/0xf4)
[<c01352c4>] (kthread) from [<c0107978>] (ret_from_fork+0x14/0x3c)
Code: e59035f0 e5935018 f57ff04f e3c55001 (f57ff04e)
---[ end trace 3d1d0d87796de344 ]---

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>

---
 drivers/gpu/drm/bridge/analogix/analogix_dp_core.c | 7 +++++++
 1 file changed, 7 insertions(+)

-- 
1.9.1

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Comments

Archit Taneja Jan. 9, 2017, 9:47 a.m. | #1
On 01/05/2017 01:01 PM, Sean Paul wrote:
> On Fri, Dec 30, 2016 at 4:57 AM, Marek Szyprowski

> <m.szyprowski@samsung.com> wrote:

>> Analogix_dp_bind() can be called from component framework, which doesn't

>> guarantee proper runtime PM state of the device during bind operation,

>> so ensure that device is runtime active before doing any register access.

>> This ensures that the power domain, to which DP module belongs, is turned

>> on. While at it, also fix the unbalanced call to phy_power_on() in

>> analogix_dp_bind() function.


Pushed to drm-misc-fixes.

Thanks,
Archit

>>

>> This patch solves the following kernel oops on Samsung Exynos5250 Snow

>> board:

>>

>> Unhandled fault: imprecise external abort (0x406) at 0x00000000

>> pgd = c0004000

>> [00000000] *pgd=00000000

>> Internal error: : 406 [#1] PREEMPT SMP ARM

>> Modules linked in:

>> CPU: 0 PID: 75 Comm: kworker/0:2 Not tainted 4.9.0 #1046

>> Hardware name: SAMSUNG EXYNOS (Flattened Device Tree)

>> Workqueue: events deferred_probe_work_func

>> task: ee272300 task.stack: ee312000

>> PC is at analogix_dp_enable_sw_function+0x18/0x2c

>> LR is at analogix_dp_init_dp+0x2c/0x50

>> ...

>> [<c03fcb38>] (analogix_dp_enable_sw_function) from [<c03fa9c4>] (analogix_dp_init_dp+0x2c/0x50)

>> [<c03fa9c4>] (analogix_dp_init_dp) from [<c03fab6c>] (analogix_dp_bind+0x184/0x42c)

>> [<c03fab6c>] (analogix_dp_bind) from [<c03fdb84>] (component_bind_all+0xf0/0x218)

>> [<c03fdb84>] (component_bind_all) from [<c03ed64c>] (exynos_drm_load+0x134/0x200)

>> [<c03ed64c>] (exynos_drm_load) from [<c03d5058>] (drm_dev_register+0xa0/0xd0)

>> [<c03d5058>] (drm_dev_register) from [<c03d66b8>] (drm_platform_init+0x58/0xb0)

>> [<c03d66b8>] (drm_platform_init) from [<c03fe0c4>] (try_to_bring_up_master+0x14c/0x188)

>> [<c03fe0c4>] (try_to_bring_up_master) from [<c03fe188>] (component_add+0x88/0x138)

>> [<c03fe188>] (component_add) from [<c0403a38>] (platform_drv_probe+0x50/0xb0)

>> [<c0403a38>] (platform_drv_probe) from [<c0402470>] (driver_probe_device+0x1f0/0x2a8)

>> [<c0402470>] (driver_probe_device) from [<c0400a54>] (bus_for_each_drv+0x44/0x8c)

>> [<c0400a54>] (bus_for_each_drv) from [<c04021f8>] (__device_attach+0x9c/0x100)

>> [<c04021f8>] (__device_attach) from [<c04018e8>] (bus_probe_device+0x84/0x8c)

>> [<c04018e8>] (bus_probe_device) from [<c0401d1c>] (deferred_probe_work_func+0x60/0x8c)

>> [<c0401d1c>] (deferred_probe_work_func) from [<c012fc14>] (process_one_work+0x120/0x318)

>> [<c012fc14>] (process_one_work) from [<c012fe34>] (process_scheduled_works+0x28/0x38)

>> [<c012fe34>] (process_scheduled_works) from [<c0130048>] (worker_thread+0x204/0x4ac)

>> [<c0130048>] (worker_thread) from [<c01352c4>] (kthread+0xd8/0xf4)

>> [<c01352c4>] (kthread) from [<c0107978>] (ret_from_fork+0x14/0x3c)

>> Code: e59035f0 e5935018 f57ff04f e3c55001 (f57ff04e)

>> ---[ end trace 3d1d0d87796de344 ]---

>>

>

> Reviewed-by: Sean Paul <seanpaul@chromium.org>

>

>> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>

>> ---

>>  drivers/gpu/drm/bridge/analogix/analogix_dp_core.c | 7 +++++++

>>  1 file changed, 7 insertions(+)

>>

>> diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c

>> index eb9bf8786c24..18eefdcbf1ba 100644

>> --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c

>> +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c

>> @@ -1382,6 +1382,7 @@ int analogix_dp_bind(struct device *dev, struct drm_device *drm_dev,

>>

>>         pm_runtime_enable(dev);

>>

>> +       pm_runtime_get_sync(dev);

>>         phy_power_on(dp->phy);

>>

>>         analogix_dp_init_dp(dp);

>> @@ -1414,9 +1415,15 @@ int analogix_dp_bind(struct device *dev, struct drm_device *drm_dev,

>>                 goto err_disable_pm_runtime;

>>         }

>>

>> +       phy_power_off(dp->phy);

>> +       pm_runtime_put(dev);

>> +

>>         return 0;

>>

>>  err_disable_pm_runtime:

>> +

>> +       phy_power_off(dp->phy);

>> +       pm_runtime_put(dev);

>>         pm_runtime_disable(dev);

>>

>>         return ret;

>> --

>> 1.9.1

>>

>

>

>


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Javier Martinez Canillas Jan. 23, 2017, 5:28 p.m. | #2
Hello Archit,

On 01/09/2017 06:47 AM, Archit Taneja wrote:
> 

> 

> On 01/05/2017 01:01 PM, Sean Paul wrote:

>> On Fri, Dec 30, 2016 at 4:57 AM, Marek Szyprowski

>> <m.szyprowski@samsung.com> wrote:

>>> Analogix_dp_bind() can be called from component framework, which doesn't

>>> guarantee proper runtime PM state of the device during bind operation,

>>> so ensure that device is runtime active before doing any register access.

>>> This ensures that the power domain, to which DP module belongs, is turned

>>> on. While at it, also fix the unbalanced call to phy_power_on() in

>>> analogix_dp_bind() function.

> 

> Pushed to drm-misc-fixes.

>


Do you know when this fix will land in mainline? The regression is still
present in v4.10-rc5:

https://storage.kernelci.org/mainline/v4.10-rc5/arm-exynos_defconfig/lab-collabora/boot-exynos5250-snow.html
 
> Thanks,

> Archit

> 


Best regards,
-- 
Javier Martinez Canillas
Open Source Group
Samsung Research America
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Archit Taneja Jan. 24, 2017, 2:40 a.m. | #3
Hi,

On 01/23/2017 10:58 PM, Javier Martinez Canillas wrote:
> Hello Archit,

>

> On 01/09/2017 06:47 AM, Archit Taneja wrote:

>>

>>

>> On 01/05/2017 01:01 PM, Sean Paul wrote:

>>> On Fri, Dec 30, 2016 at 4:57 AM, Marek Szyprowski

>>> <m.szyprowski@samsung.com> wrote:

>>>> Analogix_dp_bind() can be called from component framework, which doesn't

>>>> guarantee proper runtime PM state of the device during bind operation,

>>>> so ensure that device is runtime active before doing any register access.

>>>> This ensures that the power domain, to which DP module belongs, is turned

>>>> on. While at it, also fix the unbalanced call to phy_power_on() in

>>>> analogix_dp_bind() function.

>>

>> Pushed to drm-misc-fixes.

>>

>

> Do you know when this fix will land in mainline? The regression is still

> present in v4.10-rc5:

>

> https://storage.kernelci.org/mainline/v4.10-rc5/arm-exynos_defconfig/lab-collabora/boot-exynos5250-snow.html


It's there in Dave's 4.10-rc6 pull request:

https://lkml.org/lkml/2017/1/22/305
Archit

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Patch hide | download patch | download mbox

diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
index eb9bf8786c24..18eefdcbf1ba 100644
--- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
+++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
@@ -1382,6 +1382,7 @@  int analogix_dp_bind(struct device *dev, struct drm_device *drm_dev,
 
 	pm_runtime_enable(dev);
 
+	pm_runtime_get_sync(dev);
 	phy_power_on(dp->phy);
 
 	analogix_dp_init_dp(dp);
@@ -1414,9 +1415,15 @@  int analogix_dp_bind(struct device *dev, struct drm_device *drm_dev,
 		goto err_disable_pm_runtime;
 	}
 
+	phy_power_off(dp->phy);
+	pm_runtime_put(dev);
+
 	return 0;
 
 err_disable_pm_runtime:
+
+	phy_power_off(dp->phy);
+	pm_runtime_put(dev);
 	pm_runtime_disable(dev);
 
 	return ret;