[4.0-rc+] WARNING: CPU: 0 PID: 1 at ./drivers/dma/dmaengine.c:863 dma_async_device_register+0xe0/0x540()

[4.0-rc+] WARNING: CPU: 0 PID: 1 at ./drivers/dma/dmaengine.c:863 dma_async_device_register+0xe0/0x540()

[Peter Hurley]

First boot of 4.0-rc+ gave me [1] on a Beaglebone Black due to

commit ecc19d17868be9c9f8f00ed928791533c420f3e0
Author: Maxime Ripard <maxime.ripard@free-electrons.com>
Date:   Mon Nov 17 14:42:53 2014 +0100

    dmaengine: Add a warning for drivers not using the generic slave caps retrieval
    
    For the slave caps retrieval to be really useful, most drivers need to
    implement it.
    
    Hence, we need to be slightly more aggressive, and trigger a warning at
    registration time for drivers that don't fill their caps infos in order to
    encourage them to implement it.
    
    Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
    Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
    Signed-off-by: Vinod Koul <vinod.koul@intel.com>

Regards,
Peter Hurley

[1] 

[    1.848374] WARNING: CPU: 0 PID: 1 at /home/peter/src/kernels/mainline/drivers/dma/dmaengine.c:863 dma_async_device_register+0xe0/0x540()
[    1.860798] this driver doesn't support generic slave capabilities reporting
[    1.867893] Modules linked in:
[    1.870993] CPU: 0 PID: 1 Comm: swapper Not tainted 4.0.0-rc2+ #115
[    1.877302] Hardware name: Generic AM33XX (Flattened Device Tree)
[    1.883478] [<c00164b8>] (unwind_backtrace) from [<c00135e8>] (show_stack+0x20/0x24)
[    1.891307] [<c00135e8>] (show_stack) from [<c091f7a0>] (dump_stack+0x24/0x28)
[    1.898602] [<c091f7a0>] (dump_stack) from [<c003dff4>] (warn_slowpath_common+0x94/0xc0)
[    1.906753] [<c003dff4>] (warn_slowpath_common) from [<c003e060>] (warn_slowpath_fmt+0x40/0x48)
[    1.915515] [<c003e060>] (warn_slowpath_fmt) from [<c0561fd8>] (dma_async_device_register+0xe0/0x540)
[    1.924806] [<c0561fd8>] (dma_async_device_register) from [<c056b3cc>] (cppi41_dma_probe+0x470/0x4c0)
[    1.934397] [<c056b3cc>] (cppi41_dma_probe) from [<c05f7e6c>] (platform_drv_probe+0x54/0xb4)
[    1.942924] [<c05f7e6c>] (platform_drv_probe) from [<c05f5bac>] (driver_probe_device+0x14c/0x3a8)
[    1.951861] [<c05f5bac>] (driver_probe_device) from [<c05f5e58>] (__device_attach+0x50/0x54)
[    1.960360] [<c05f5e58>] (__device_attach) from [<c05f3c94>] (bus_for_each_drv+0x68/0x9c)
[    1.968596] [<c05f3c94>] (bus_for_each_drv) from [<c05f59ec>] (device_attach+0x84/0x98)
[    1.976656] [<c05f59ec>] (device_attach) from [<c05f4e70>] (bus_probe_device+0x94/0xb8)
[    1.984717] [<c05f4e70>] (bus_probe_device) from [<c05f2cb0>] (device_add+0x3dc/0x59c)
[    1.992700] [<c05f2cb0>] (device_add) from [<c07a6f5c>] (of_device_add+0x44/0x4c)
[    2.000242] [<c07a6f5c>] (of_device_add) from [<c07a78d4>] (of_platform_device_create_pdata+0x140/0x234)
[    2.009788] [<c07a78d4>] (of_platform_device_create_pdata) from [<c07a7af8>] (of_platform_bus_create+0x10c/0x234)
[    2.020118] [<c07a7af8>] (of_platform_bus_create) from [<c07a7dbc>] (of_platform_populate+0x6c/0xc8)
[    2.029319] [<c07a7dbc>] (of_platform_populate) from [<c06e83f8>] (am335x_child_probe+0x38/0x54)
[    2.038168] [<c06e83f8>] (am335x_child_probe) from [<c05f7e6c>] (platform_drv_probe+0x54/0xb4)
[    2.046840] [<c05f7e6c>] (platform_drv_probe) from [<c05f5bac>] (driver_probe_device+0x14c/0x3a8)
[    2.055774] [<c05f5bac>] (driver_probe_device) from [<c05f5ef8>] (__driver_attach+0x9c/0xa0)
[    2.064268] [<c05f5ef8>] (__driver_attach) from [<c05f3bcc>] (bus_for_each_dev+0x70/0xa4)
[    2.072501] [<c05f3bcc>] (bus_for_each_dev) from [<c05f555c>] (driver_attach+0x2c/0x30)
[    2.080561] [<c05f555c>] (driver_attach) from [<c05f515c>] (bus_add_driver+0x170/0x22c)
[    2.088623] [<c05f515c>] (bus_add_driver) from [<c05f6878>] (driver_register+0x88/0x108)
[    2.096770] [<c05f6878>] (driver_register) from [<c05f7d98>] (__platform_driver_register+0x64/0x6c)
[    2.105884] [<c05f7d98>] (__platform_driver_register) from [<c0d8df0c>] (am335x_child_init+0x1c/0x20)
[    2.115171] [<c0d8df0c>] (am335x_child_init) from [<c0008ad8>] (do_one_initcall+0xe8/0x230)
[    2.123592] [<c0008ad8>] (do_one_initcall) from [<c0d45f90>] (kernel_init_freeable+0x1e0/0x284)
[    2.132355] [<c0d45f90>] (kernel_init_freeable) from [<c0919044>] (kernel_init+0x1c/0x100)
[    2.140681] [<c0919044>] (kernel_init) from [<c000f8d0>] (ret_from_fork+0x14/0x24)

Re: [4.0-rc+] WARNING: CPU: 0 PID: 1 at ./drivers/dma/dmaengine.c:863 dma_async_device_register+0xe0/0x540()

[Vinod Koul]

On Thu, Mar 05, 2015 at 10:04:21AM -0500, Peter Hurley wrote:
> First boot of 4.0-rc+ gave me [1] on a Beaglebone Black due to
> 
The warning is intentional to get driver fixed and give the right behaviour

Felipe had sent a patch for this but that one needs an update

-- 
~Vinod
> commit ecc19d17868be9c9f8f00ed928791533c420f3e0
> Author: Maxime Ripard <maxime.ripard@free-electrons.com>
> Date:   Mon Nov 17 14:42:53 2014 +0100
> 
>     dmaengine: Add a warning for drivers not using the generic slave caps retrieval
>     
>     For the slave caps retrieval to be really useful, most drivers need to
>     implement it.
>     
>     Hence, we need to be slightly more aggressive, and trigger a warning at
>     registration time for drivers that don't fill their caps infos in order to
>     encourage them to implement it.
>     
>     Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
>     Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
>     Signed-off-by: Vinod Koul <vinod.koul@intel.com>
> 
> Regards,
> Peter Hurley
> 
> [1] 
> 
> [    1.848374] WARNING: CPU: 0 PID: 1 at /home/peter/src/kernels/mainline/drivers/dma/dmaengine.c:863 dma_async_device_register+0xe0/0x540()
> [    1.860798] this driver doesn't support generic slave capabilities reporting
> [    1.867893] Modules linked in:
> [    1.870993] CPU: 0 PID: 1 Comm: swapper Not tainted 4.0.0-rc2+ #115
> [    1.877302] Hardware name: Generic AM33XX (Flattened Device Tree)
> [    1.883478] [<c00164b8>] (unwind_backtrace) from [<c00135e8>] (show_stack+0x20/0x24)
> [    1.891307] [<c00135e8>] (show_stack) from [<c091f7a0>] (dump_stack+0x24/0x28)
> [    1.898602] [<c091f7a0>] (dump_stack) from [<c003dff4>] (warn_slowpath_common+0x94/0xc0)
> [    1.906753] [<c003dff4>] (warn_slowpath_common) from [<c003e060>] (warn_slowpath_fmt+0x40/0x48)
> [    1.915515] [<c003e060>] (warn_slowpath_fmt) from [<c0561fd8>] (dma_async_device_register+0xe0/0x540)
> [    1.924806] [<c0561fd8>] (dma_async_device_register) from [<c056b3cc>] (cppi41_dma_probe+0x470/0x4c0)
> [    1.934397] [<c056b3cc>] (cppi41_dma_probe) from [<c05f7e6c>] (platform_drv_probe+0x54/0xb4)
> [    1.942924] [<c05f7e6c>] (platform_drv_probe) from [<c05f5bac>] (driver_probe_device+0x14c/0x3a8)
> [    1.951861] [<c05f5bac>] (driver_probe_device) from [<c05f5e58>] (__device_attach+0x50/0x54)
> [    1.960360] [<c05f5e58>] (__device_attach) from [<c05f3c94>] (bus_for_each_drv+0x68/0x9c)
> [    1.968596] [<c05f3c94>] (bus_for_each_drv) from [<c05f59ec>] (device_attach+0x84/0x98)
> [    1.976656] [<c05f59ec>] (device_attach) from [<c05f4e70>] (bus_probe_device+0x94/0xb8)
> [    1.984717] [<c05f4e70>] (bus_probe_device) from [<c05f2cb0>] (device_add+0x3dc/0x59c)
> [    1.992700] [<c05f2cb0>] (device_add) from [<c07a6f5c>] (of_device_add+0x44/0x4c)
> [    2.000242] [<c07a6f5c>] (of_device_add) from [<c07a78d4>] (of_platform_device_create_pdata+0x140/0x234)
> [    2.009788] [<c07a78d4>] (of_platform_device_create_pdata) from [<c07a7af8>] (of_platform_bus_create+0x10c/0x234)
> [    2.020118] [<c07a7af8>] (of_platform_bus_create) from [<c07a7dbc>] (of_platform_populate+0x6c/0xc8)
> [    2.029319] [<c07a7dbc>] (of_platform_populate) from [<c06e83f8>] (am335x_child_probe+0x38/0x54)
> [    2.038168] [<c06e83f8>] (am335x_child_probe) from [<c05f7e6c>] (platform_drv_probe+0x54/0xb4)
> [    2.046840] [<c05f7e6c>] (platform_drv_probe) from [<c05f5bac>] (driver_probe_device+0x14c/0x3a8)
> [    2.055774] [<c05f5bac>] (driver_probe_device) from [<c05f5ef8>] (__driver_attach+0x9c/0xa0)
> [    2.064268] [<c05f5ef8>] (__driver_attach) from [<c05f3bcc>] (bus_for_each_dev+0x70/0xa4)
> [    2.072501] [<c05f3bcc>] (bus_for_each_dev) from [<c05f555c>] (driver_attach+0x2c/0x30)
> [    2.080561] [<c05f555c>] (driver_attach) from [<c05f515c>] (bus_add_driver+0x170/0x22c)
> [    2.088623] [<c05f515c>] (bus_add_driver) from [<c05f6878>] (driver_register+0x88/0x108)
> [    2.096770] [<c05f6878>] (driver_register) from [<c05f7d98>] (__platform_driver_register+0x64/0x6c)
> [    2.105884] [<c05f7d98>] (__platform_driver_register) from [<c0d8df0c>] (am335x_child_init+0x1c/0x20)
> [    2.115171] [<c0d8df0c>] (am335x_child_init) from [<c0008ad8>] (do_one_initcall+0xe8/0x230)
> [    2.123592] [<c0008ad8>] (do_one_initcall) from [<c0d45f90>] (kernel_init_freeable+0x1e0/0x284)
> [    2.132355] [<c0d45f90>] (kernel_init_freeable) from [<c0919044>] (kernel_init+0x1c/0x100)
> [    2.140681] [<c0919044>] (kernel_init) from [<c000f8d0>] (ret_from_fork+0x14/0x24)
> 

-- 

Re: [4.0-rc+] WARNING: CPU: 0 PID: 1 at ./drivers/dma/dmaengine.c:863 dma_async_device_register+0xe0/0x540()

[Peter Hurley]

On 03/05/2015 11:12 AM, Vinod Koul wrote:
> On Thu, Mar 05, 2015 at 10:04:21AM -0500, Peter Hurley wrote:
>> > First boot of 4.0-rc+ gave me [1] on a Beaglebone Black due to
>> > 
> The warning is intentional to get driver fixed and give the right behaviour
> 
> Felipe had sent a patch for this but that one needs an update

Vinod,

Felipe's patch never made it to mainline, and this warning is 
still happening on 4.0-rc7 so please revert for 4.0-final.

Regards,
Peter Hurley


> -- ~Vinod
>> > commit ecc19d17868be9c9f8f00ed928791533c420f3e0
>> > Author: Maxime Ripard <maxime.ripard@free-electrons.com>
>> > Date:   Mon Nov 17 14:42:53 2014 +0100
>> > 
>> >     dmaengine: Add a warning for drivers not using the generic slave caps retrieval
>> >     
>> >     For the slave caps retrieval to be really useful, most drivers need to
>> >     implement it.
>> >     
>> >     Hence, we need to be slightly more aggressive, and trigger a warning at
>> >     registration time for drivers that don't fill their caps infos in order to
>> >     encourage them to implement it.
>> >     
>> >     Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
>> >     Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
>> >     Signed-off-by: Vinod Koul <vinod.koul@intel.com>
>> > 
>> > Regards,
>> > Peter Hurley
>> > 
>> > [1] 
>> > 
>> > [    1.848374] WARNING: CPU: 0 PID: 1 at /home/peter/src/kernels/mainline/drivers/dma/dmaengine.c:863 dma_async_device_register+0xe0/0x540()
>> > [    1.860798] this driver doesn't support generic slave capabilities reporting
>> > [    1.867893] Modules linked in:
>> > [    1.870993] CPU: 0 PID: 1 Comm: swapper Not tainted 4.0.0-rc2+ #115
>> > [    1.877302] Hardware name: Generic AM33XX (Flattened Device Tree)
>> > [    1.883478] [<c00164b8>] (unwind_backtrace) from [<c00135e8>] (show_stack+0x20/0x24)
>> > [    1.891307] [<c00135e8>] (show_stack) from [<c091f7a0>] (dump_stack+0x24/0x28)
>> > [    1.898602] [<c091f7a0>] (dump_stack) from [<c003dff4>] (warn_slowpath_common+0x94/0xc0)
>> > [    1.906753] [<c003dff4>] (warn_slowpath_common) from [<c003e060>] (warn_slowpath_fmt+0x40/0x48)
>> > [    1.915515] [<c003e060>] (warn_slowpath_fmt) from [<c0561fd8>] (dma_async_device_register+0xe0/0x540)
>> > [    1.924806] [<c0561fd8>] (dma_async_device_register) from [<c056b3cc>] (cppi41_dma_probe+0x470/0x4c0)
>> > [    1.934397] [<c056b3cc>] (cppi41_dma_probe) from [<c05f7e6c>] (platform_drv_probe+0x54/0xb4)
>> > [    1.942924] [<c05f7e6c>] (platform_drv_probe) from [<c05f5bac>] (driver_probe_device+0x14c/0x3a8)
>> > [    1.951861] [<c05f5bac>] (driver_probe_device) from [<c05f5e58>] (__device_attach+0x50/0x54)
>> > [    1.960360] [<c05f5e58>] (__device_attach) from [<c05f3c94>] (bus_for_each_drv+0x68/0x9c)
>> > [    1.968596] [<c05f3c94>] (bus_for_each_drv) from [<c05f59ec>] (device_attach+0x84/0x98)
>> > [    1.976656] [<c05f59ec>] (device_attach) from [<c05f4e70>] (bus_probe_device+0x94/0xb8)
>> > [    1.984717] [<c05f4e70>] (bus_probe_device) from [<c05f2cb0>] (device_add+0x3dc/0x59c)
>> > [    1.992700] [<c05f2cb0>] (device_add) from [<c07a6f5c>] (of_device_add+0x44/0x4c)
>> > [    2.000242] [<c07a6f5c>] (of_device_add) from [<c07a78d4>] (of_platform_device_create_pdata+0x140/0x234)
>> > [    2.009788] [<c07a78d4>] (of_platform_device_create_pdata) from [<c07a7af8>] (of_platform_bus_create+0x10c/0x234)
>> > [    2.020118] [<c07a7af8>] (of_platform_bus_create) from [<c07a7dbc>] (of_platform_populate+0x6c/0xc8)
>> > [    2.029319] [<c07a7dbc>] (of_platform_populate) from [<c06e83f8>] (am335x_child_probe+0x38/0x54)
>> > [    2.038168] [<c06e83f8>] (am335x_child_probe) from [<c05f7e6c>] (platform_drv_probe+0x54/0xb4)
>> > [    2.046840] [<c05f7e6c>] (platform_drv_probe) from [<c05f5bac>] (driver_probe_device+0x14c/0x3a8)
>> > [    2.055774] [<c05f5bac>] (driver_probe_device) from [<c05f5ef8>] (__driver_attach+0x9c/0xa0)
>> > [    2.064268] [<c05f5ef8>] (__driver_attach) from [<c05f3bcc>] (bus_for_each_dev+0x70/0xa4)
>> > [    2.072501] [<c05f3bcc>] (bus_for_each_dev) from [<c05f555c>] (driver_attach+0x2c/0x30)
>> > [    2.080561] [<c05f555c>] (driver_attach) from [<c05f515c>] (bus_add_driver+0x170/0x22c)
>> > [    2.088623] [<c05f515c>] (bus_add_driver) from [<c05f6878>] (driver_register+0x88/0x108)
>> > [    2.096770] [<c05f6878>] (driver_register) from [<c05f7d98>] (__platform_driver_register+0x64/0x6c)
>> > [    2.105884] [<c05f7d98>] (__platform_driver_register) from [<c0d8df0c>] (am335x_child_init+0x1c/0x20)
>> > [    2.115171] [<c0d8df0c>] (am335x_child_init) from [<c0008ad8>] (do_one_initcall+0xe8/0x230)
>> > [    2.123592] [<c0008ad8>] (do_one_initcall) from [<c0d45f90>] (kernel_init_freeable+0x1e0/0x284)
>> > [    2.132355] [<c0d45f90>] (kernel_init_freeable) from [<c0919044>] (kernel_init+0x1c/0x100)
>> > [    2.140681] [<c0919044>] (kernel_init) from [<c000f8d0>] (ret_from_fork+0x14/0x24)
>> > 
> -- 

Re: [4.0-rc+] WARNING: CPU: 0 PID: 1 at ./drivers/dma/dmaengine.c:863 dma_async_device_register+0xe0/0x540()

[Maxime Ripard]

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On Wed, Apr 08, 2015 at 11:53:33AM -0400, Peter Hurley wrote:
> On 03/05/2015 11:12 AM, Vinod Koul wrote:
> > On Thu, Mar 05, 2015 at 10:04:21AM -0500, Peter Hurley wrote:
> >> > First boot of 4.0-rc+ gave me [1] on a Beaglebone Black due to
> >> > 
> > The warning is intentional to get driver fixed and give the right behaviour
> > 
> > Felipe had sent a patch for this but that one needs an update
> 
> Vinod,
> 
> Felipe's patch never made it to mainline, and this warning is 
> still happening on 4.0-rc7 so please revert for 4.0-final.

That patch isn't introducing any regression. I fail to see how that
justifies a revert so late in the release cycle.

Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

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Re: [4.0-rc+] WARNING: CPU: 0 PID: 1 at ./drivers/dma/dmaengine.c:863 dma_async_device_register+0xe0/0x540()

[Peter Hurley]

On 04/08/2015 11:59 AM, Maxime Ripard wrote:
> On Wed, Apr 08, 2015 at 11:53:33AM -0400, Peter Hurley wrote:
>> On 03/05/2015 11:12 AM, Vinod Koul wrote:
>>> On Thu, Mar 05, 2015 at 10:04:21AM -0500, Peter Hurley wrote:
>>>>> First boot of 4.0-rc+ gave me [1] on a Beaglebone Black due to
>>>>>
>>> The warning is intentional to get driver fixed and give the right behaviour
>>>
>>> Felipe had sent a patch for this but that one needs an update
>>
>> Vinod,
>>
>> Felipe's patch never made it to mainline, and this warning is 
>> still happening on 4.0-rc7 so please revert for 4.0-final.
> 
> That patch isn't introducing any regression. I fail to see how that
> justifies a revert so late in the release cycle.

Arguably it never should have been introduced in the first place, and
this was at least known since Mar 5 (and likely earlier); arguing that
it's late in the cycle is a bit disingenuous.

Regards,
Peter Hurley

Re: [4.0-rc+] WARNING: CPU: 0 PID: 1 at ./drivers/dma/dmaengine.c:863 dma_async_device_register+0xe0/0x540()

[Felipe Balbi]

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On Wed, Apr 08, 2015 at 12:07:14PM -0400, Peter Hurley wrote:
> On 04/08/2015 11:59 AM, Maxime Ripard wrote:
> > On Wed, Apr 08, 2015 at 11:53:33AM -0400, Peter Hurley wrote:
> >> On 03/05/2015 11:12 AM, Vinod Koul wrote:
> >>> On Thu, Mar 05, 2015 at 10:04:21AM -0500, Peter Hurley wrote:
> >>>>> First boot of 4.0-rc+ gave me [1] on a Beaglebone Black due to
> >>>>>
> >>> The warning is intentional to get driver fixed and give the right behaviour
> >>>
> >>> Felipe had sent a patch for this but that one needs an update
> >>
> >> Vinod,
> >>
> >> Felipe's patch never made it to mainline, and this warning is 
> >> still happening on 4.0-rc7 so please revert for 4.0-final.
> > 
> > That patch isn't introducing any regression. I fail to see how that
> > justifies a revert so late in the release cycle.
> 
> Arguably it never should have been introduced in the first place, and
> this was at least known since Mar 5 (and likely earlier); arguing that
> it's late in the cycle is a bit disingenuous.

In Vinod's defense, he asked for changes in my patch which I didn't have
time to implement (as of yet). Have been rather busy lately with a bunch
of other things, I'll try to get to those changes ASAP, just need to
finish up a bisect on another platform.

cheers

-- 
balbi

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Re: [4.0-rc+] WARNING: CPU: 0 PID: 1 at ./drivers/dma/dmaengine.c:863 dma_async_device_register+0xe0/0x540()

[Peter Hurley]

On 04/08/2015 12:09 PM, Felipe Balbi wrote:
> On Wed, Apr 08, 2015 at 12:07:14PM -0400, Peter Hurley wrote:
>> On 04/08/2015 11:59 AM, Maxime Ripard wrote:
>>> On Wed, Apr 08, 2015 at 11:53:33AM -0400, Peter Hurley wrote:
>>>> On 03/05/2015 11:12 AM, Vinod Koul wrote:
>>>>> On Thu, Mar 05, 2015 at 10:04:21AM -0500, Peter Hurley wrote:
>>>>>>> First boot of 4.0-rc+ gave me [1] on a Beaglebone Black due to
>>>>>>>
>>>>> The warning is intentional to get driver fixed and give the right behaviour
>>>>>
>>>>> Felipe had sent a patch for this but that one needs an update
>>>>
>>>> Vinod,
>>>>
>>>> Felipe's patch never made it to mainline, and this warning is 
>>>> still happening on 4.0-rc7 so please revert for 4.0-final.
>>>
>>> That patch isn't introducing any regression. I fail to see how that
>>> justifies a revert so late in the release cycle.
>>
>> Arguably it never should have been introduced in the first place, and
>> this was at least known since Mar 5 (and likely earlier); arguing that
>> it's late in the cycle is a bit disingenuous.
> 
> In Vinod's defense, he asked for changes in my patch which I didn't have
> time to implement (as of yet). Have been rather busy lately with a bunch
> of other things, I'll try to get to those changes ASAP, just need to
> finish up a bisect on another platform.

Ok, but Vinod's on vacation, and adding new functionality now definitely
seems too late.

Re: [4.0-rc+] WARNING: CPU: 0 PID: 1 at ./drivers/dma/dmaengine.c:863 dma_async_device_register+0xe0/0x540()

[Peter Hurley]

Linus,

I just got an automated bounce reply from Vinod Koul stating
he's on vacation til April 12th, so I'd appreciate if you could
revert this commit [1] for 4.0-final.

The commit generates a WARNING [2] in a effort to get dmaengine drivers
to add new functionality.

I sent Vinod a note that this was happening on Beaglebone Blacks
back on Mar 5 (-rc3). He thought the functionality would be added
shortly, but it wasn't, so the WARNING is still happening on -rc7.

Regards,
Peter Hurley


On 04/08/2015 11:53 AM, Peter Hurley wrote:
> On 03/05/2015 11:12 AM, Vinod Koul wrote:
>> On Thu, Mar 05, 2015 at 10:04:21AM -0500, Peter Hurley wrote:
>>>> First boot of 4.0-rc+ gave me [1] on a Beaglebone Black due to
>>>>
>> The warning is intentional to get driver fixed and give the right behaviour
>>
>> Felipe had sent a patch for this but that one needs an update
> 
> Vinod,
> 
> Felipe's patch never made it to mainline, and this warning is 
> still happening on 4.0-rc7 so please revert for 4.0-final.
> 
> Regards,
> Peter Hurley
> 
> 
>> -- ~Vinod

[1]

>>>> commit ecc19d17868be9c9f8f00ed928791533c420f3e0
>>>> Author: Maxime Ripard <maxime.ripard@free-electrons.com>
>>>> Date:   Mon Nov 17 14:42:53 2014 +0100
>>>>
>>>>     dmaengine: Add a warning for drivers not using the generic slave caps retrieval
>>>>     
>>>>     For the slave caps retrieval to be really useful, most drivers need to
>>>>     implement it.
>>>>     
>>>>     Hence, we need to be slightly more aggressive, and trigger a warning at
>>>>     registration time for drivers that don't fill their caps infos in order to
>>>>     encourage them to implement it.
>>>>     
>>>>     Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
>>>>     Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
>>>>     Signed-off-by: Vinod Koul <vinod.koul@intel.com>

[2]

>>>> [    1.848374] WARNING: CPU: 0 PID: 1 at /home/peter/src/kernels/mainline/drivers/dma/dmaengine.c:863 dma_async_device_register+0xe0/0x540()
>>>> [    1.860798] this driver doesn't support generic slave capabilities reporting
>>>> [    1.867893] Modules linked in:
>>>> [    1.870993] CPU: 0 PID: 1 Comm: swapper Not tainted 4.0.0-rc2+ #115
>>>> [    1.877302] Hardware name: Generic AM33XX (Flattened Device Tree)
>>>> [    1.883478] [<c00164b8>] (unwind_backtrace) from [<c00135e8>] (show_stack+0x20/0x24)
>>>> [    1.891307] [<c00135e8>] (show_stack) from [<c091f7a0>] (dump_stack+0x24/0x28)
>>>> [    1.898602] [<c091f7a0>] (dump_stack) from [<c003dff4>] (warn_slowpath_common+0x94/0xc0)
>>>> [    1.906753] [<c003dff4>] (warn_slowpath_common) from [<c003e060>] (warn_slowpath_fmt+0x40/0x48)
>>>> [    1.915515] [<c003e060>] (warn_slowpath_fmt) from [<c0561fd8>] (dma_async_device_register+0xe0/0x540)
>>>> [    1.924806] [<c0561fd8>] (dma_async_device_register) from [<c056b3cc>] (cppi41_dma_probe+0x470/0x4c0)
>>>> [    1.934397] [<c056b3cc>] (cppi41_dma_probe) from [<c05f7e6c>] (platform_drv_probe+0x54/0xb4)
>>>> [    1.942924] [<c05f7e6c>] (platform_drv_probe) from [<c05f5bac>] (driver_probe_device+0x14c/0x3a8)
>>>> [    1.951861] [<c05f5bac>] (driver_probe_device) from [<c05f5e58>] (__device_attach+0x50/0x54)
>>>> [    1.960360] [<c05f5e58>] (__device_attach) from [<c05f3c94>] (bus_for_each_drv+0x68/0x9c)
>>>> [    1.968596] [<c05f3c94>] (bus_for_each_drv) from [<c05f59ec>] (device_attach+0x84/0x98)
>>>> [    1.976656] [<c05f59ec>] (device_attach) from [<c05f4e70>] (bus_probe_device+0x94/0xb8)
>>>> [    1.984717] [<c05f4e70>] (bus_probe_device) from [<c05f2cb0>] (device_add+0x3dc/0x59c)
>>>> [    1.992700] [<c05f2cb0>] (device_add) from [<c07a6f5c>] (of_device_add+0x44/0x4c)
>>>> [    2.000242] [<c07a6f5c>] (of_device_add) from [<c07a78d4>] (of_platform_device_create_pdata+0x140/0x234)
>>>> [    2.009788] [<c07a78d4>] (of_platform_device_create_pdata) from [<c07a7af8>] (of_platform_bus_create+0x10c/0x234)
>>>> [    2.020118] [<c07a7af8>] (of_platform_bus_create) from [<c07a7dbc>] (of_platform_populate+0x6c/0xc8)
>>>> [    2.029319] [<c07a7dbc>] (of_platform_populate) from [<c06e83f8>] (am335x_child_probe+0x38/0x54)
>>>> [    2.038168] [<c06e83f8>] (am335x_child_probe) from [<c05f7e6c>] (platform_drv_probe+0x54/0xb4)
>>>> [    2.046840] [<c05f7e6c>] (platform_drv_probe) from [<c05f5bac>] (driver_probe_device+0x14c/0x3a8)
>>>> [    2.055774] [<c05f5bac>] (driver_probe_device) from [<c05f5ef8>] (__driver_attach+0x9c/0xa0)
>>>> [    2.064268] [<c05f5ef8>] (__driver_attach) from [<c05f3bcc>] (bus_for_each_dev+0x70/0xa4)
>>>> [    2.072501] [<c05f3bcc>] (bus_for_each_dev) from [<c05f555c>] (driver_attach+0x2c/0x30)
>>>> [    2.080561] [<c05f555c>] (driver_attach) from [<c05f515c>] (bus_add_driver+0x170/0x22c)
>>>> [    2.088623] [<c05f515c>] (bus_add_driver) from [<c05f6878>] (driver_register+0x88/0x108)
>>>> [    2.096770] [<c05f6878>] (driver_register) from [<c05f7d98>] (__platform_driver_register+0x64/0x6c)
>>>> [    2.105884] [<c05f7d98>] (__platform_driver_register) from [<c0d8df0c>] (am335x_child_init+0x1c/0x20)
>>>> [    2.115171] [<c0d8df0c>] (am335x_child_init) from [<c0008ad8>] (do_one_initcall+0xe8/0x230)
>>>> [    2.123592] [<c0008ad8>] (do_one_initcall) from [<c0d45f90>] (kernel_init_freeable+0x1e0/0x284)
>>>> [    2.132355] [<c0d45f90>] (kernel_init_freeable) from [<c0919044>] (kernel_init+0x1c/0x100)
>>>> [    2.140681] [<c0919044>] (kernel_init) from [<c000f8d0>] (ret_from_fork+0x14/0x24)

Re: [4.0-rc+] WARNING: CPU: 0 PID: 1 at ./drivers/dma/dmaengine.c:863 dma_async_device_register+0xe0/0x540()

[Maxime Ripard]

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On Wed, Apr 08, 2015 at 12:26:13PM -0400, Peter Hurley wrote:
> Linus,
> 
> I just got an automated bounce reply from Vinod Koul stating
> he's on vacation til April 12th, so I'd appreciate if you could
> revert this commit [1] for 4.0-final.
> 
> The commit generates a WARNING [2] in a effort to get dmaengine drivers
> to add new functionality.
> 
> I sent Vinod a note that this was happening on Beaglebone Blacks
> back on Mar 5 (-rc3). He thought the functionality would be added
> shortly, but it wasn't, so the WARNING is still happening on -rc7.

For completeness, note that this is just a warning generated at
boot. It doesn't change the previous behaviour in any way.

Any existing code will work just as well as it used to.

Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

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Re: [4.0-rc+] WARNING: CPU: 0 PID: 1 at ./drivers/dma/dmaengine.c:863 dma_async_device_register+0xe0/0x540()

[Maxime Ripard]

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On Wed, Apr 08, 2015 at 12:07:14PM -0400, Peter Hurley wrote:
> On 04/08/2015 11:59 AM, Maxime Ripard wrote:
> > On Wed, Apr 08, 2015 at 11:53:33AM -0400, Peter Hurley wrote:
> >> On 03/05/2015 11:12 AM, Vinod Koul wrote:
> >>> On Thu, Mar 05, 2015 at 10:04:21AM -0500, Peter Hurley wrote:
> >>>>> First boot of 4.0-rc+ gave me [1] on a Beaglebone Black due to
> >>>>>
> >>> The warning is intentional to get driver fixed and give the right behaviour
> >>>
> >>> Felipe had sent a patch for this but that one needs an update
> >>
> >> Vinod,
> >>
> >> Felipe's patch never made it to mainline, and this warning is 
> >> still happening on 4.0-rc7 so please revert for 4.0-final.
> > 
> > That patch isn't introducing any regression. I fail to see how that
> > justifies a revert so late in the release cycle.
> 
> Arguably it never should have been introduced in the first place

Upon which arguments? So far, I've seen none but "my boot logs look
bad now".

> and this was at least known since Mar 5 (and likely earlier);
> arguing that it's late in the cycle is a bit disingenuous.

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

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Re: [4.0-rc+] WARNING: CPU: 0 PID: 1 at ./drivers/dma/dmaengine.c:863 dma_async_device_register+0xe0/0x540()

[Peter Hurley]

On 04/09/2015 03:09 AM, Maxime Ripard wrote:
> On Wed, Apr 08, 2015 at 12:07:14PM -0400, Peter Hurley wrote:
>> On 04/08/2015 11:59 AM, Maxime Ripard wrote:
>>> On Wed, Apr 08, 2015 at 11:53:33AM -0400, Peter Hurley wrote:
>>>> On 03/05/2015 11:12 AM, Vinod Koul wrote:
>>>>> On Thu, Mar 05, 2015 at 10:04:21AM -0500, Peter Hurley wrote:
>>>>>>> First boot of 4.0-rc+ gave me [1] on a Beaglebone Black due to
>>>>>>>
>>>>> The warning is intentional to get driver fixed and give the right behaviour
>>>>>
>>>>> Felipe had sent a patch for this but that one needs an update
>>>>
>>>> Vinod,
>>>>
>>>> Felipe's patch never made it to mainline, and this warning is 
>>>> still happening on 4.0-rc7 so please revert for 4.0-final.
>>>
>>> That patch isn't introducing any regression. I fail to see how that
>>> justifies a revert so late in the release cycle.
>>
>> Arguably it never should have been introduced in the first place
> 
> Upon which arguments? So far, I've seen none but "my boot logs look
> bad now".

1. Every subsystem has drivers that don't fully conform to a desired
   interface. If even a small fraction did this, everyone's logs would
   be cluttered with this garbage. For that matter, if just the serial
   subsystem alone did this, logs would be awash in warnings.

2. Now _every_ dmaengine driver "fix" for this will need to be pushed
   to -stable.

>> and this was at least known since Mar 5 (and likely earlier);
>> arguing that it's late in the cycle is a bit disingenuous.

Re: [4.0-rc+] WARNING: CPU: 0 PID: 1 at ./drivers/dma/dmaengine.c:863 dma_async_device_register+0xe0/0x540()

[Maxime Ripard]

[-- Attachment #1: Type: text/plain, Size: 1889 bytes --]

On Thu, Apr 09, 2015 at 06:31:13AM -0400, Peter Hurley wrote:
> On 04/09/2015 03:09 AM, Maxime Ripard wrote:
> > On Wed, Apr 08, 2015 at 12:07:14PM -0400, Peter Hurley wrote:
> >> On 04/08/2015 11:59 AM, Maxime Ripard wrote:
> >>> On Wed, Apr 08, 2015 at 11:53:33AM -0400, Peter Hurley wrote:
> >>>> On 03/05/2015 11:12 AM, Vinod Koul wrote:
> >>>>> On Thu, Mar 05, 2015 at 10:04:21AM -0500, Peter Hurley wrote:
> >>>>>>> First boot of 4.0-rc+ gave me [1] on a Beaglebone Black due to
> >>>>>>>
> >>>>> The warning is intentional to get driver fixed and give the right behaviour
> >>>>>
> >>>>> Felipe had sent a patch for this but that one needs an update
> >>>>
> >>>> Vinod,
> >>>>
> >>>> Felipe's patch never made it to mainline, and this warning is 
> >>>> still happening on 4.0-rc7 so please revert for 4.0-final.
> >>>
> >>> That patch isn't introducing any regression. I fail to see how that
> >>> justifies a revert so late in the release cycle.
> >>
> >> Arguably it never should have been introduced in the first place
> > 
> > Upon which arguments? So far, I've seen none but "my boot logs look
> > bad now".
> 
> 1. Every subsystem has drivers that don't fully conform to a desired
>    interface. If even a small fraction did this, everyone's logs would
>    be cluttered with this garbage. For that matter, if just the serial
>    subsystem alone did this, logs would be awash in warnings.

And a lot of subsystems do this for drivers where the way to fix this
is not clear and/or easy to obtain.

Which is exactly the case here.

> 2. Now _every_ dmaengine driver "fix" for this will need to be pushed
>    to -stable.

It won't. Such changes are not elligible, especially since they are
not critical fixes.

Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

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