Stack-frame warnings in display_mode_vba_32.c

Posted by Paul E. McKenney 3 years, 8 months ago

Hello!

I am seeing the following in allmodconfig builds of recent -next on x86:

drivers/gpu/drm/amd/amdgpu/../display/dc/dml/dcn32/display_mode_vba_32.c: In function ‘DISPCLKDPPCLKDCFCLKDeepSleepPrefetchParametersWatermarksAndPerformanceCalculation’:
drivers/gpu/drm/amd/amdgpu/../display/dc/dml/dcn32/display_mode_vba_32.c:1659:1: error: the frame size of 2144 bytes is larger than 2048 bytes [-Werror=frame-larger-than=]
 1659 | }
      | ^
drivers/gpu/drm/amd/amdgpu/../display/dc/dml/dcn32/display_mode_vba_32.c: In function ‘dml32_ModeSupportAndSystemConfigurationFull’:
drivers/gpu/drm/amd/amdgpu/../display/dc/dml/dcn32/display_mode_vba_32.c:3799:1: error: the frame size of 2480 bytes is larger than 2048 bytes [-Werror=frame-larger-than=]
 3799 | } // ModeSupportAndSystemConfigurationFull
      | ^

Bisection located the commit shown below.  Doing an allmodconfig build
on this commit reproduces the error, its parent builds fine.

Thoughts?

							Thanx, Paul

------------------------------------------------------------------------

commit 3876a8b5e241081b2a519f848a65c00d8e6cd124
Author: Guenter Roeck <linux@roeck-us.net>
Date:   Tue Jul 12 15:42:47 2022 -0700

    drm/amd/display: Enable building new display engine with KCOV enabled
    
    The new display engine uses floating point math, which is not supported
    by KCOV. Commit 9d1d02ff3678 ("drm/amd/display: Don't build DCN1 when kcov
    is enabled") tried to work around the problem by disabling
    CONFIG_DRM_AMD_DC_DCN if KCOV_INSTRUMENT_ALL and KCOV_ENABLE_COMPARISONS
    are enabled. The result is that KCOV can not be enabled on systems which
    require this display engine. A much simpler and less invasive solution is
    to disable KCOV selectively when compiling the display enagine while
    keeping it enabled for the rest of the kernel.
    
    Fixes: 9d1d02ff3678 ("drm/amd/display: Don't build DCN1 when kcov is enabled")
    Cc: Arnd Bergmann <arnd@arndb.de>
    Cc: Leo Li <sunpeng.li@amd.com>
    Reviewed-by: Harry Wentland <harry.wentland@amd.com>
    Signed-off-by: Guenter Roeck <linux@roeck-us.net>
    Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/amd/display/Kconfig b/drivers/gpu/drm/amd/display/Kconfig
index b4029c0d5d8c5..96cbc87f7b6b8 100644
--- a/drivers/gpu/drm/amd/display/Kconfig
+++ b/drivers/gpu/drm/amd/display/Kconfig
@@ -6,7 +6,7 @@ config DRM_AMD_DC
 	bool "AMD DC - Enable new display engine"
 	default y
 	select SND_HDA_COMPONENT if SND_HDA_CORE
-	select DRM_AMD_DC_DCN if (X86 || PPC64) && !(KCOV_INSTRUMENT_ALL && KCOV_ENABLE_COMPARISONS)
+	select DRM_AMD_DC_DCN if (X86 || PPC64)
 	help
 	  Choose this option if you want to use the new display engine
 	  support for AMDGPU. This adds required support for Vega and
diff --git a/drivers/gpu/drm/amd/display/dc/Makefile b/drivers/gpu/drm/amd/display/dc/Makefile
index 273f8f2c8e020..b9effadfc4bb7 100644
--- a/drivers/gpu/drm/amd/display/dc/Makefile
+++ b/drivers/gpu/drm/amd/display/dc/Makefile
@@ -25,6 +25,9 @@
 DC_LIBS = basics bios dml clk_mgr dce gpio irq link virtual
 
 ifdef CONFIG_DRM_AMD_DC_DCN
+
+KCOV_INSTRUMENT := n
+
 DC_LIBS += dcn20
 DC_LIBS += dsc
 DC_LIBS += dcn10

Re: Stack-frame warnings in display_mode_vba_32.c

Posted by André Almeida 3 years, 8 months ago

Hi Paul,

Às 23:25 de 29/07/22, Paul E. McKenney escreveu:
> Hello!
> 
> I am seeing the following in allmodconfig builds of recent -next on x86:
> 
> drivers/gpu/drm/amd/amdgpu/../display/dc/dml/dcn32/display_mode_vba_32.c: In function ‘DISPCLKDPPCLKDCFCLKDeepSleepPrefetchParametersWatermarksAndPerformanceCalculation’:
> drivers/gpu/drm/amd/amdgpu/../display/dc/dml/dcn32/display_mode_vba_32.c:1659:1: error: the frame size of 2144 bytes is larger than 2048 bytes [-Werror=frame-larger-than=]
>  1659 | }
>       | ^
> drivers/gpu/drm/amd/amdgpu/../display/dc/dml/dcn32/display_mode_vba_32.c: In function ‘dml32_ModeSupportAndSystemConfigurationFull’:
> drivers/gpu/drm/amd/amdgpu/../display/dc/dml/dcn32/display_mode_vba_32.c:3799:1: error: the frame size of 2480 bytes is larger than 2048 bytes [-Werror=frame-larger-than=]
>  3799 | } // ModeSupportAndSystemConfigurationFull
>       | ^

I think they are fixed at amd-staging-drm-next:

git log --oneline amd/amd-staging-drm-next
drivers/gpu/drm/amd/display/dc/dml/dcn32/display_mode_vba_32.c
953daa61981b drm/amd/display: Reduce stack size in the mode support function
361e705e712d drm/amd/display: reduce stack for
dml32_CalculatePrefetchSchedule
f2dbf5a4dd1e drm/amd/display: reduce stack for
dml32_CalculateWatermarksMALLUseAndDRAMSpeedChangeSupport
a0a68cda2ef8 drm/amd/display: reduce stack for dml32_CalculateVMRowAndSwath
ca6730ca0f01 drm/amd/display: reduce stack for
dml32_CalculateSwathAndDETConfiguration
593eef8c1a5e drm/amd/display: reduce stack size in dcn32 dml (v2)

https://gitlab.freedesktop.org/agd5f/linux/-/commits/amd-staging-drm-next/drivers/gpu/drm/amd/display/dc/dml/dcn32/display_mode_vba_32.c

> 
> Bisection located the commit shown below.  Doing an allmodconfig build
> on this commit reproduces the error, its parent builds fine.
> 
> Thoughts?
> 
> 							Thanx, Paul
> 
> ------------------------------------------------------------------------
> 
> commit 3876a8b5e241081b2a519f848a65c00d8e6cd124
> Author: Guenter Roeck <linux@roeck-us.net>
> Date:   Tue Jul 12 15:42:47 2022 -0700
> 
>     drm/amd/display: Enable building new display engine with KCOV enabled
>     
>     The new display engine uses floating point math, which is not supported
>     by KCOV. Commit 9d1d02ff3678 ("drm/amd/display: Don't build DCN1 when kcov
>     is enabled") tried to work around the problem by disabling
>     CONFIG_DRM_AMD_DC_DCN if KCOV_INSTRUMENT_ALL and KCOV_ENABLE_COMPARISONS
>     are enabled. The result is that KCOV can not be enabled on systems which
>     require this display engine. A much simpler and less invasive solution is
>     to disable KCOV selectively when compiling the display enagine while
>     keeping it enabled for the rest of the kernel.
>     
>     Fixes: 9d1d02ff3678 ("drm/amd/display: Don't build DCN1 when kcov is enabled")
>     Cc: Arnd Bergmann <arnd@arndb.de>
>     Cc: Leo Li <sunpeng.li@amd.com>
>     Reviewed-by: Harry Wentland <harry.wentland@amd.com>
>     Signed-off-by: Guenter Roeck <linux@roeck-us.net>
>     Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
> 
> diff --git a/drivers/gpu/drm/amd/display/Kconfig b/drivers/gpu/drm/amd/display/Kconfig
> index b4029c0d5d8c5..96cbc87f7b6b8 100644
> --- a/drivers/gpu/drm/amd/display/Kconfig
> +++ b/drivers/gpu/drm/amd/display/Kconfig
> @@ -6,7 +6,7 @@ config DRM_AMD_DC
>  	bool "AMD DC - Enable new display engine"
>  	default y
>  	select SND_HDA_COMPONENT if SND_HDA_CORE
> -	select DRM_AMD_DC_DCN if (X86 || PPC64) && !(KCOV_INSTRUMENT_ALL && KCOV_ENABLE_COMPARISONS)
> +	select DRM_AMD_DC_DCN if (X86 || PPC64)
>  	help
>  	  Choose this option if you want to use the new display engine
>  	  support for AMDGPU. This adds required support for Vega and
> diff --git a/drivers/gpu/drm/amd/display/dc/Makefile b/drivers/gpu/drm/amd/display/dc/Makefile
> index 273f8f2c8e020..b9effadfc4bb7 100644
> --- a/drivers/gpu/drm/amd/display/dc/Makefile
> +++ b/drivers/gpu/drm/amd/display/dc/Makefile
> @@ -25,6 +25,9 @@
>  DC_LIBS = basics bios dml clk_mgr dce gpio irq link virtual
>  
>  ifdef CONFIG_DRM_AMD_DC_DCN
> +
> +KCOV_INSTRUMENT := n
> +
>  DC_LIBS += dcn20
>  DC_LIBS += dsc
>  DC_LIBS += dcn10

Re: Stack-frame warnings in display_mode_vba_32.c

Posted by Paul E. McKenney 3 years, 8 months ago

On Fri, Jul 29, 2022 at 11:41:55PM -0300, André Almeida wrote:
> Hi Paul,
> 
> Às 23:25 de 29/07/22, Paul E. McKenney escreveu:
> > Hello!
> > 
> > I am seeing the following in allmodconfig builds of recent -next on x86:
> > 
> > drivers/gpu/drm/amd/amdgpu/../display/dc/dml/dcn32/display_mode_vba_32.c: In function ‘DISPCLKDPPCLKDCFCLKDeepSleepPrefetchParametersWatermarksAndPerformanceCalculation’:
> > drivers/gpu/drm/amd/amdgpu/../display/dc/dml/dcn32/display_mode_vba_32.c:1659:1: error: the frame size of 2144 bytes is larger than 2048 bytes [-Werror=frame-larger-than=]
> >  1659 | }
> >       | ^
> > drivers/gpu/drm/amd/amdgpu/../display/dc/dml/dcn32/display_mode_vba_32.c: In function ‘dml32_ModeSupportAndSystemConfigurationFull’:
> > drivers/gpu/drm/amd/amdgpu/../display/dc/dml/dcn32/display_mode_vba_32.c:3799:1: error: the frame size of 2480 bytes is larger than 2048 bytes [-Werror=frame-larger-than=]
> >  3799 | } // ModeSupportAndSystemConfigurationFull
> >       | ^
> 
> I think they are fixed at amd-staging-drm-next:
> 
> git log --oneline amd/amd-staging-drm-next
> drivers/gpu/drm/amd/display/dc/dml/dcn32/display_mode_vba_32.c
> 953daa61981b drm/amd/display: Reduce stack size in the mode support function
> 361e705e712d drm/amd/display: reduce stack for
> dml32_CalculatePrefetchSchedule
> f2dbf5a4dd1e drm/amd/display: reduce stack for
> dml32_CalculateWatermarksMALLUseAndDRAMSpeedChangeSupport
> a0a68cda2ef8 drm/amd/display: reduce stack for dml32_CalculateVMRowAndSwath
> ca6730ca0f01 drm/amd/display: reduce stack for
> dml32_CalculateSwathAndDETConfiguration
> 593eef8c1a5e drm/amd/display: reduce stack size in dcn32 dml (v2)
> 
> https://gitlab.freedesktop.org/agd5f/linux/-/commits/amd-staging-drm-next/drivers/gpu/drm/amd/display/dc/dml/dcn32/display_mode_vba_32.c

Very good, thank you!  I will test again on the next -next.

							Thanx, Paul

> > Bisection located the commit shown below.  Doing an allmodconfig build
> > on this commit reproduces the error, its parent builds fine.
> > 
> > Thoughts?
> > 
> > 							Thanx, Paul
> > 
> > ------------------------------------------------------------------------
> > 
> > commit 3876a8b5e241081b2a519f848a65c00d8e6cd124
> > Author: Guenter Roeck <linux@roeck-us.net>
> > Date:   Tue Jul 12 15:42:47 2022 -0700
> > 
> >     drm/amd/display: Enable building new display engine with KCOV enabled
> >     
> >     The new display engine uses floating point math, which is not supported
> >     by KCOV. Commit 9d1d02ff3678 ("drm/amd/display: Don't build DCN1 when kcov
> >     is enabled") tried to work around the problem by disabling
> >     CONFIG_DRM_AMD_DC_DCN if KCOV_INSTRUMENT_ALL and KCOV_ENABLE_COMPARISONS
> >     are enabled. The result is that KCOV can not be enabled on systems which
> >     require this display engine. A much simpler and less invasive solution is
> >     to disable KCOV selectively when compiling the display enagine while
> >     keeping it enabled for the rest of the kernel.
> >     
> >     Fixes: 9d1d02ff3678 ("drm/amd/display: Don't build DCN1 when kcov is enabled")
> >     Cc: Arnd Bergmann <arnd@arndb.de>
> >     Cc: Leo Li <sunpeng.li@amd.com>
> >     Reviewed-by: Harry Wentland <harry.wentland@amd.com>
> >     Signed-off-by: Guenter Roeck <linux@roeck-us.net>
> >     Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
> > 
> > diff --git a/drivers/gpu/drm/amd/display/Kconfig b/drivers/gpu/drm/amd/display/Kconfig
> > index b4029c0d5d8c5..96cbc87f7b6b8 100644
> > --- a/drivers/gpu/drm/amd/display/Kconfig
> > +++ b/drivers/gpu/drm/amd/display/Kconfig
> > @@ -6,7 +6,7 @@ config DRM_AMD_DC
> >  	bool "AMD DC - Enable new display engine"
> >  	default y
> >  	select SND_HDA_COMPONENT if SND_HDA_CORE
> > -	select DRM_AMD_DC_DCN if (X86 || PPC64) && !(KCOV_INSTRUMENT_ALL && KCOV_ENABLE_COMPARISONS)
> > +	select DRM_AMD_DC_DCN if (X86 || PPC64)
> >  	help
> >  	  Choose this option if you want to use the new display engine
> >  	  support for AMDGPU. This adds required support for Vega and
> > diff --git a/drivers/gpu/drm/amd/display/dc/Makefile b/drivers/gpu/drm/amd/display/dc/Makefile
> > index 273f8f2c8e020..b9effadfc4bb7 100644
> > --- a/drivers/gpu/drm/amd/display/dc/Makefile
> > +++ b/drivers/gpu/drm/amd/display/dc/Makefile
> > @@ -25,6 +25,9 @@
> >  DC_LIBS = basics bios dml clk_mgr dce gpio irq link virtual
> >  
> >  ifdef CONFIG_DRM_AMD_DC_DCN
> > +
> > +KCOV_INSTRUMENT := n
> > +
> >  DC_LIBS += dcn20
> >  DC_LIBS += dsc
> >  DC_LIBS += dcn10

Re: Stack-frame warnings in display_mode_vba_32.c

Posted by Guenter Roeck 3 years, 8 months ago

On 7/29/22 22:12, Paul E. McKenney wrote:
> On Fri, Jul 29, 2022 at 11:41:55PM -0300, André Almeida wrote:
>> Hi Paul,
>>
>> Às 23:25 de 29/07/22, Paul E. McKenney escreveu:
>>> Hello!
>>>
>>> I am seeing the following in allmodconfig builds of recent -next on x86:
>>>
>>> drivers/gpu/drm/amd/amdgpu/../display/dc/dml/dcn32/display_mode_vba_32.c: In function ‘DISPCLKDPPCLKDCFCLKDeepSleepPrefetchParametersWatermarksAndPerformanceCalculation’:
>>> drivers/gpu/drm/amd/amdgpu/../display/dc/dml/dcn32/display_mode_vba_32.c:1659:1: error: the frame size of 2144 bytes is larger than 2048 bytes [-Werror=frame-larger-than=]
>>>   1659 | }
>>>        | ^
>>> drivers/gpu/drm/amd/amdgpu/../display/dc/dml/dcn32/display_mode_vba_32.c: In function ‘dml32_ModeSupportAndSystemConfigurationFull’:
>>> drivers/gpu/drm/amd/amdgpu/../display/dc/dml/dcn32/display_mode_vba_32.c:3799:1: error: the frame size of 2480 bytes is larger than 2048 bytes [-Werror=frame-larger-than=]
>>>   3799 | } // ModeSupportAndSystemConfigurationFull
>>>        | ^
>>
>> I think they are fixed at amd-staging-drm-next:
>>
>> git log --oneline amd/amd-staging-drm-next
>> drivers/gpu/drm/amd/display/dc/dml/dcn32/display_mode_vba_32.c
>> 953daa61981b drm/amd/display: Reduce stack size in the mode support function
>> 361e705e712d drm/amd/display: reduce stack for
>> dml32_CalculatePrefetchSchedule
>> f2dbf5a4dd1e drm/amd/display: reduce stack for
>> dml32_CalculateWatermarksMALLUseAndDRAMSpeedChangeSupport
>> a0a68cda2ef8 drm/amd/display: reduce stack for dml32_CalculateVMRowAndSwath
>> ca6730ca0f01 drm/amd/display: reduce stack for
>> dml32_CalculateSwathAndDETConfiguration
>> 593eef8c1a5e drm/amd/display: reduce stack size in dcn32 dml (v2)
>>
>> https://gitlab.freedesktop.org/agd5f/linux/-/commits/amd-staging-drm-next/drivers/gpu/drm/amd/display/dc/dml/dcn32/display_mode_vba_32.c
> 
> Very good, thank you!  I will test again on the next -next.
> 

Did you try next-20220728 ?

groeck@server:~/src/linux-next$ git describe
next-20220728
groeck@server:~/src/linux-next$ git log --oneline drivers/gpu/drm/amd/amdgpu/../display/dc/dml/dcn32/display_mode_vba_32.c
1b54a0121dba drm/amd/display: Reduce stack size in the mode support function
86e4863e67a9 drm/amd/display: reduce stack for dml32_CalculatePrefetchSchedule
3c3abac60117 drm/amd/display: reduce stack for dml32_CalculateWatermarksMALLUseAndDRAMSpeedChangeSupport
c3b3f9ba25e6 drm/amd/display: reduce stack for dml32_CalculateVMRowAndSwath
bac4b41d917a drm/amd/display: reduce stack for dml32_CalculateSwathAndDETConfiguration
7acc487ab57e drm/amd/display: reduce stack size in dcn32 dml (v2)

Guenter

Re: Stack-frame warnings in display_mode_vba_32.c

Posted by Paul E. McKenney 3 years, 8 months ago

On Sat, Jul 30, 2022 at 02:06:10AM -0700, Guenter Roeck wrote:
> On 7/29/22 22:12, Paul E. McKenney wrote:
> > On Fri, Jul 29, 2022 at 11:41:55PM -0300, André Almeida wrote:
> > > Hi Paul,
> > > 
> > > Às 23:25 de 29/07/22, Paul E. McKenney escreveu:
> > > > Hello!
> > > > 
> > > > I am seeing the following in allmodconfig builds of recent -next on x86:
> > > > 
> > > > drivers/gpu/drm/amd/amdgpu/../display/dc/dml/dcn32/display_mode_vba_32.c: In function ‘DISPCLKDPPCLKDCFCLKDeepSleepPrefetchParametersWatermarksAndPerformanceCalculation’:
> > > > drivers/gpu/drm/amd/amdgpu/../display/dc/dml/dcn32/display_mode_vba_32.c:1659:1: error: the frame size of 2144 bytes is larger than 2048 bytes [-Werror=frame-larger-than=]
> > > >   1659 | }
> > > >        | ^
> > > > drivers/gpu/drm/amd/amdgpu/../display/dc/dml/dcn32/display_mode_vba_32.c: In function ‘dml32_ModeSupportAndSystemConfigurationFull’:
> > > > drivers/gpu/drm/amd/amdgpu/../display/dc/dml/dcn32/display_mode_vba_32.c:3799:1: error: the frame size of 2480 bytes is larger than 2048 bytes [-Werror=frame-larger-than=]
> > > >   3799 | } // ModeSupportAndSystemConfigurationFull
> > > >        | ^
> > > 
> > > I think they are fixed at amd-staging-drm-next:
> > > 
> > > git log --oneline amd/amd-staging-drm-next
> > > drivers/gpu/drm/amd/display/dc/dml/dcn32/display_mode_vba_32.c
> > > 953daa61981b drm/amd/display: Reduce stack size in the mode support function
> > > 361e705e712d drm/amd/display: reduce stack for
> > > dml32_CalculatePrefetchSchedule
> > > f2dbf5a4dd1e drm/amd/display: reduce stack for
> > > dml32_CalculateWatermarksMALLUseAndDRAMSpeedChangeSupport
> > > a0a68cda2ef8 drm/amd/display: reduce stack for dml32_CalculateVMRowAndSwath
> > > ca6730ca0f01 drm/amd/display: reduce stack for
> > > dml32_CalculateSwathAndDETConfiguration
> > > 593eef8c1a5e drm/amd/display: reduce stack size in dcn32 dml (v2)
> > > 
> > > https://gitlab.freedesktop.org/agd5f/linux/-/commits/amd-staging-drm-next/drivers/gpu/drm/amd/display/dc/dml/dcn32/display_mode_vba_32.c
> > 
> > Very good, thank you!  I will test again on the next -next.
> > 
> 
> Did you try next-20220728 ?
> 
> groeck@server:~/src/linux-next$ git describe
> next-20220728
> groeck@server:~/src/linux-next$ git log --oneline drivers/gpu/drm/amd/amdgpu/../display/dc/dml/dcn32/display_mode_vba_32.c
> 1b54a0121dba drm/amd/display: Reduce stack size in the mode support function
> 86e4863e67a9 drm/amd/display: reduce stack for dml32_CalculatePrefetchSchedule
> 3c3abac60117 drm/amd/display: reduce stack for dml32_CalculateWatermarksMALLUseAndDRAMSpeedChangeSupport
> c3b3f9ba25e6 drm/amd/display: reduce stack for dml32_CalculateVMRowAndSwath
> bac4b41d917a drm/amd/display: reduce stack for dml32_CalculateSwathAndDETConfiguration
> 7acc487ab57e drm/amd/display: reduce stack size in dcn32 dml (v2)

Indeed, next-20220728 does avoid the problem, thank you!

							Thanx, Paul