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Date:   Sat, 30 Jul 2022 14:09:54 -0700
From:   "Paul E. McKenney" <paulmck@kernel.org>
To:     Guenter Roeck <linux@roeck-us.net>
Cc:     =?iso-8859-1?Q?Andr=E9?= Almeida <andrealmeid@igalia.com>,
        sfr@canb.auug.org.au, harry.wentland@amd.com, sunpeng.li@amd.com,
        arnd@arndb.de, alexander.deucher@amd.com,
        linux-next@vger.kernel.org, dri-devel@lists.freedesktop.org,
        amd-gfx@lists.freedesktop.org, linux-kernel@vger.kernel.org
Subject: Re: Stack-frame warnings in display_mode_vba_32.c
Message-ID: <20220730210954.GU2860372@paulmck-ThinkPad-P17-Gen-1>
Reply-To: paulmck@kernel.org
References: <20220730022532.GA1234397@paulmck-ThinkPad-P17-Gen-1>
 <85a49b72-8bb7-b3b3-8a69-2c90cda8079d@igalia.com>
 <20220730051238.GR2860372@paulmck-ThinkPad-P17-Gen-1>
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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