Re: [PATCH] Revert "drm/panthor: Fix undefined panthor_device_suspend/resume symbol issue"

[Boris Brezillon <boris.brezillon@collabora.com>]

On Mon, 11 Mar 2024 14:41:42 +0000
Liviu Dudau <liviu.dudau@arm.com> wrote:

> On Mon, Mar 11, 2024 at 02:26:50PM +0200, Jani Nikula wrote:
> > On Mon, 11 Mar 2024, Boris Brezillon <boris.brezillon@collabora.com> wrote:  
> > > On Mon, 11 Mar 2024 13:51:46 +0200
> > > Jani Nikula <jani.nikula@intel.com> wrote:
> > >  
> > >> On Mon, 11 Mar 2024, Boris Brezillon <boris.brezillon@collabora.com> wrote:  
> > >> > On Mon, 11 Mar 2024 13:16:19 +0200
> > >> > Jani Nikula <jani.nikula@intel.com> wrote:
> > >> >    
> > >> >> This reverts commit 674dc7f61aefea81901c21402946074927e63f1a.
> > >> >> 
> > >> >> The commit causes a recursive dependency in kconfig:
> > >> >> 
> > >> >> drivers/iommu/Kconfig:14:error: recursive dependency detected!
> > >> >> drivers/iommu/Kconfig:14:	symbol IOMMU_SUPPORT is selected by DRM_PANTHOR
> > >> >> drivers/gpu/drm/panthor/Kconfig:3:	symbol DRM_PANTHOR depends on PM
> > >> >> kernel/power/Kconfig:183:	symbol PM is selected by PM_SLEEP
> > >> >> kernel/power/Kconfig:117:	symbol PM_SLEEP depends on HIBERNATE_CALLBACKS
> > >> >> kernel/power/Kconfig:35:	symbol HIBERNATE_CALLBACKS is selected by XEN_SAVE_RESTORE
> > >> >> arch/x86/xen/Kconfig:67:	symbol XEN_SAVE_RESTORE depends on XEN
> > >> >> arch/x86/xen/Kconfig:6:	symbol XEN depends on PARAVIRT
> > >> >> arch/x86/Kconfig:781:	symbol PARAVIRT is selected by HYPERV
> > >> >> drivers/hv/Kconfig:5:	symbol HYPERV depends on X86_LOCAL_APIC
> > >> >> arch/x86/Kconfig:1106:	symbol X86_LOCAL_APIC depends on X86_UP_APIC
> > >> >> arch/x86/Kconfig:1081:	symbol X86_UP_APIC prompt is visible depending on PCI_MSI
> > >> >> drivers/pci/Kconfig:39:	symbol PCI_MSI is selected by AMD_IOMMU
> > >> >> drivers/iommu/amd/Kconfig:3:	symbol AMD_IOMMU depends on IOMMU_SUPPORT
> > >> >> For a resolution refer to Documentation/kbuild/kconfig-language.rst
> > >> >> subsection "Kconfig recursive dependency limitations"
> > >> >> 
> > >> >> Fixes: 674dc7f61aef ("drm/panthor: Fix undefined panthor_device_suspend/resume symbol issue")
> > >> >> Cc: Boris Brezillon <boris.brezillon@collabora.com>
> > >> >> Cc: Liviu Dudau <liviu.dudau@arm.com>
> > >> >> Cc: Steven Price <steven.price@arm.com>
> > >> >> Signed-off-by: Jani Nikula <jani.nikula@intel.com>    
> > >> >
> > >> > Acked-by: Boris Brezillon <boris.brezillon@collabora.com>    
> > >> 
> > >> Your suggestion select -> depends on IOMMU_SUPPORT seems to also work,
> > >> at least for me. Want to send a patch for that instead of me merging the
> > >> revert?  
> > >
> > > I replied on the other thread :-). I think we're better off reverting
> > > the faulty commit, so we can discuss how to fix the original issue
> > > properly without blocking the build.  
> > 
> > Thanks, pushed to drm-misc-next.  
> 
> So with this revert we're OK with an undefined symbol if !CONFIG_PM, but we're not happy
> with a recursive dependency that is only triggered for COMPILE_TEST? I would've thought
> IOMMU_SUPPORT options is a better one.

No worries, we have plenty of time to fix this. Just didn't want to
rush a fix before discussing it with you and Steve.