[PATCH 0/2] can: m_can_platform: Bug fix of kernel panic for

[PATCH 0/2] can: m_can_platform: Bug fix of kernel panic for

[Pankaj Sharma]

The current code is failing while clock prepare enable because of not
getting proper clock from platform device. 

[    0.852089] Call trace:
[    0.854516]  0xffff0000fa22a668
[    0.857638]  clk_prepare+0x20/0x34
[    0.861019]  m_can_runtime_resume+0x2c/0xe4
[    0.865180]  pm_generic_runtime_resume+0x28/0x38
[    0.869770]  __rpm_callback+0x16c/0x1bc
[    0.873583]  rpm_callback+0x24/0x78
[    0.877050]  rpm_resume+0x428/0x560
[    0.880517]  __pm_runtime_resume+0x7c/0xa8
[    0.884593]  m_can_clk_start.isra.9.part.10+0x1c/0xa8
[    0.889618]  m_can_class_register+0x138/0x370
[    0.893950]  m_can_plat_probe+0x120/0x170
[    0.897939]  platform_drv_probe+0x4c/0xa0
[    0.901924]  really_probe+0xd8/0x31c
[    0.905477]  driver_probe_device+0x58/0xe8
[    0.909551]  device_driver_attach+0x68/0x70
[    0.913711]  __driver_attach+0x9c/0xf8
[    0.917437]  bus_for_each_dev+0x50/0xa0
[    0.921251]  driver_attach+0x20/0x28
[    0.924804]  bus_add_driver+0x148/0x1fc
[    0.928617]  driver_register+0x6c/0x124
[    0.932431]  __platform_driver_register+0x48/0x50
[    0.937113]  m_can_plat_driver_init+0x18/0x20
[    0.941446]  do_one_initcall+0x4c/0x19c
[    0.945259]  kernel_init_freeable+0x1d0/0x280
[    0.949591]  kernel_init+0x10/0x100
[    0.953057]  ret_from_fork+0x10/0x18
[    0.956614] Code: 00000000 00000000 00000000 00000000 (fa22a668) 
[    0.962681] ---[ end trace 881f71bd609de763 ]---
[    0.967301] Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b

A device driver for CAN controller hardware registers itself with the
Linux network layer as a network device. So, the driver data for m_can
should ideally be of type net_device. 

Further even when passing the proper net device in probe function the
code was hanging because of the function m_can_runtime_resume() getting
recursively called from m_can_class_resume().

Pankaj Sharma (2):
  can: m_can_platform: set net_device structure as driver data
  can: m_can_platform: remove unnecessary m_can_class_resume() call

 drivers/net/can/m_can/m_can_platform.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

-- 
2.7.4

[PATCH 1/2] can: m_can_platform: set net_device structure as driver data

[Pankaj Sharma]

A device driver for CAN controller hardware registers itself with the
Linux network layer as a network device. So, the driver data for m_can
should ideally be of type net_device.

Fixes: f524f829b75a ("can: m_can: Create a m_can platform framework")

Signed-off-by: Pankaj Sharma <pankj.sharma@samsung.com>
Signed-off-by: Sriram Dash <sriram.dash@samsung.com>
---
 drivers/net/can/m_can/m_can_platform.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/can/m_can/m_can_platform.c b/drivers/net/can/m_can/m_can_platform.c
index 6ac4c35..2eaa354 100644
--- a/drivers/net/can/m_can/m_can_platform.c
+++ b/drivers/net/can/m_can/m_can_platform.c
@@ -107,7 +107,7 @@ static int m_can_plat_probe(struct platform_device *pdev)
 
 	mcan_class->is_peripheral = false;
 
-	platform_set_drvdata(pdev, mcan_class->dev);
+	platform_set_drvdata(pdev, mcan_class->net);
 
 	m_can_init_ram(mcan_class);
 
-- 
2.7.4

Re: [PATCH 1/2] can: m_can_platform: set net_device structure as driver data

[Dan Murphy]

Pankaj

On 11/19/19 4:20 AM, Pankaj Sharma wrote:
> A device driver for CAN controller hardware registers itself with the
> Linux network layer as a network device. So, the driver data for m_can
> should ideally be of type net_device.
>
> Fixes: f524f829b75a ("can: m_can: Create a m_can platform framework")
>
> Signed-off-by: Pankaj Sharma <pankj.sharma@samsung.com>
> Signed-off-by: Sriram Dash <sriram.dash@samsung.com>
> ---
>   drivers/net/can/m_can/m_can_platform.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/net/can/m_can/m_can_platform.c b/drivers/net/can/m_can/m_can_platform.c
> index 6ac4c35..2eaa354 100644
> --- a/drivers/net/can/m_can/m_can_platform.c
> +++ b/drivers/net/can/m_can/m_can_platform.c
> @@ -107,7 +107,7 @@ static int m_can_plat_probe(struct platform_device *pdev)
>   
>   	mcan_class->is_peripheral = false;
>   
> -	platform_set_drvdata(pdev, mcan_class->dev);
> +	platform_set_drvdata(pdev, mcan_class->net);
>   
>   	m_can_init_ram(mcan_class);
>   

Thanks for the fix.

Acked-by: Dan Murphy <dmurphy@ti.com>

[PATCH 2/2] can: m_can_platform: remove unnecessary m_can_class_resume() call

[Pankaj Sharma]

The function m_can_runtime_resume() is getting recursively called from
m_can_class_resume(). This results in a lock up.

We need not call m_can_class_resume() during m_can_runtime_resume().

Fixes: f524f829b75a ("can: m_can: Create a m_can platform framework")

Signed-off-by: Pankaj Sharma <pankj.sharma@samsung.com>
Signed-off-by: Sriram Dash <sriram.dash@samsung.com>
---
 drivers/net/can/m_can/m_can_platform.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/drivers/net/can/m_can/m_can_platform.c b/drivers/net/can/m_can/m_can_platform.c
index 2eaa354..38ea5e6 100644
--- a/drivers/net/can/m_can/m_can_platform.c
+++ b/drivers/net/can/m_can/m_can_platform.c
@@ -166,8 +166,6 @@ static int __maybe_unused m_can_runtime_resume(struct device *dev)
 	if (err)
 		clk_disable_unprepare(mcan_class->hclk);
 
-	m_can_class_resume(dev);
-
 	return err;
 }
 
-- 
2.7.4

Re: [PATCH 2/2] can: m_can_platform: remove unnecessary m_can_class_resume() call

[Dan Murphy]

Pankaj

On 11/19/19 4:20 AM, Pankaj Sharma wrote:
> The function m_can_runtime_resume() is getting recursively called from
> m_can_class_resume(). This results in a lock up.
>
> We need not call m_can_class_resume() during m_can_runtime_resume().
>
> Fixes: f524f829b75a ("can: m_can: Create a m_can platform framework")
>
> Signed-off-by: Pankaj Sharma <pankj.sharma@samsung.com>
> Signed-off-by: Sriram Dash <sriram.dash@samsung.com>
> ---
>   drivers/net/can/m_can/m_can_platform.c | 2 --
>   1 file changed, 2 deletions(-)
>
> diff --git a/drivers/net/can/m_can/m_can_platform.c b/drivers/net/can/m_can/m_can_platform.c
> index 2eaa354..38ea5e6 100644
> --- a/drivers/net/can/m_can/m_can_platform.c
> +++ b/drivers/net/can/m_can/m_can_platform.c
> @@ -166,8 +166,6 @@ static int __maybe_unused m_can_runtime_resume(struct device *dev)
>   	if (err)
>   		clk_disable_unprepare(mcan_class->hclk);
>   
> -	m_can_class_resume(dev);
> -
>   	return err;
>   }
>   
Acked-by: Dan Murphy <dmurphy@ti.com>

Re: [PATCH 0/2] can: m_can_platform: Bug fix of kernel panic for

[Dan Murphy]

Pankaj

On 11/19/19 4:20 AM, Pankaj Sharma wrote:
> The current code is failing while clock prepare enable because of not
> getting proper clock from platform device.
> A device driver for CAN controller hardware registers itself with the
> Linux network layer as a network device. So, the driver data for m_can
> should ideally be of type net_device.
>
> Further even when passing the proper net device in probe function the
> code was hanging because of the function m_can_runtime_resume() getting
> recursively called from m_can_class_resume().
>
> Pankaj Sharma (2):
>    can: m_can_platform: set net_device structure as driver data
>    can: m_can_platform: remove unnecessary m_can_class_resume() call

Did you CC: linux-stable for these?  We are probably going to have 
customers picking up 5.4 LTS and would need these bug fixes.

Or at the very least see if the stable automation will pick these up.

Dan

RE: [PATCH 0/2] can: m_can_platform: Bug fix of kernel panic for

[pankj.sharma]

> From: Dan Murphy <dmurphy@ti.com>
> Subject: Re: [PATCH 0/2] can: m_can_platform: Bug fix of kernel panic for
> 
> Pankaj
> 
> On 11/19/19 4:20 AM, Pankaj Sharma wrote:
> > The current code is failing while clock prepare enable because of not
> > getting proper clock from platform device.
> > A device driver for CAN controller hardware registers itself with the
> > Linux network layer as a network device. So, the driver data for m_can
> > should ideally be of type net_device.
> >
> > Further even when passing the proper net device in probe function the
> > code was hanging because of the function m_can_runtime_resume()
> > getting recursively called from m_can_class_resume().
> >
> > Pankaj Sharma (2):
> >    can: m_can_platform: set net_device structure as driver data
> >    can: m_can_platform: remove unnecessary m_can_class_resume() call
> 
> Did you CC: linux-stable for these?  We are probably going to have customers
> picking up 5.4 LTS and would need these bug fixes.
Hello Dan, 
I haven’t copied to linux-stable, but the patches are already in linux-stable branch. 
You can check in following link.
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/log/?h=linux-5.4.y

Pankaj

> 
> Or at the very least see if the stable automation will pick these up.
> 
> Dan
> 

Re: [PATCH 0/2] can: m_can_platform: Bug fix of kernel panic for

[Marc Kleine-Budde]

[-- Attachment #1.1: Type: text/plain, Size: 1273 bytes --]

On 12/5/19 9:57 PM, Dan Murphy wrote:
> Pankaj
> 
> On 11/19/19 4:20 AM, Pankaj Sharma wrote:
>> The current code is failing while clock prepare enable because of not
>> getting proper clock from platform device.
>> A device driver for CAN controller hardware registers itself with the
>> Linux network layer as a network device. So, the driver data for m_can
>> should ideally be of type net_device.
>>
>> Further even when passing the proper net device in probe function the
>> code was hanging because of the function m_can_runtime_resume() getting
>> recursively called from m_can_class_resume().
>>
>> Pankaj Sharma (2):
>>    can: m_can_platform: set net_device structure as driver data
>>    can: m_can_platform: remove unnecessary m_can_class_resume() call
> 
> Did you CC: linux-stable for these?  We are probably going to have 
> customers picking up 5.4 LTS and would need these bug fixes.

Both patches made it into the v5.4 release. So no need for stable.

Marc

-- 
Pengutronix e.K.                 | Marc Kleine-Budde           |
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