drivers/gpu/drm/bridge/samsung-dsim.c link error

drivers/gpu/drm/bridge/samsung-dsim.c link error

[Aleksandr Nogikh]

Hello,

We've been seing the following linker error on arm64 syzbot instances:

ld.lld: error: undefined symbol: phy_mipi_dphy_get_default_config_for_hsclk
>>> referenced by samsung-dsim.c:731 (drivers/gpu/drm/bridge/samsung-dsim.c:731)
>>>               drivers/gpu/drm/bridge/samsung-dsim.o:(samsung_dsim_init) in archive vmlinux.a

Steps to reproduce on the latest linux-next:

$ git checkout next-20230803
$ wget -O '.config' 'https://raw.githubusercontent.com/google/syzkaller/master/dashboard/config/linux/upstream-arm64-kasan.config'
$ make CC=clang ARCH=arm64 LD=ld.lld CROSS_COMPILE=aarch64-linux-gnu- olddefconfig

This also prints:

WARNING: unmet direct dependencies detected for GENERIC_PHY_MIPI_DPHY
  Depends on [n]: GENERIC_PHY [=n]
  Selected by [y]:
  - DRM_NWL_MIPI_DSI [=y] && DRM_BRIDGE [=y] && DRM [=y] && COMMON_CLK [=y] && OF [=y] && HAS_IOMEM [=y]
  - DRM_SAMSUNG_DSIM [=y] && DRM [=y] && DRM_BRIDGE [=y] && COMMON_CLK [=y] && OF [=y] && HAS_IOMEM [=y]

$ make CC=clang ARCH=arm64 LD=ld.lld CROSS_COMPILE=aarch64-linux-gnu- -j$(nproc)

The kernel should have still compiled fine even despite the message above, right?

Could you please take a look?

-- 
Thank you!
Aleksandr

Re: drivers/gpu/drm/bridge/samsung-dsim.c link error

[Adam Ford]

On Thu, Aug 3, 2023 at 9:42 AM Aleksandr Nogikh <nogikh@google.com> wrote:
>
> Hello,
>
> We've been seing the following linker error on arm64 syzbot instances:
>
> ld.lld: error: undefined symbol: phy_mipi_dphy_get_default_config_for_hsclk
> >>> referenced by samsung-dsim.c:731 (drivers/gpu/drm/bridge/samsung-dsim.c:731)
> >>>               drivers/gpu/drm/bridge/samsung-dsim.o:(samsung_dsim_init) in archive vmlinux.a
>
> Steps to reproduce on the latest linux-next:
>
> $ git checkout next-20230803
> $ wget -O '.config' 'https://raw.githubusercontent.com/google/syzkaller/master/dashboard/config/linux/upstream-arm64-kasan.config'
> $ make CC=clang ARCH=arm64 LD=ld.lld CROSS_COMPILE=aarch64-linux-gnu- olddefconfig
>
> This also prints:
>
> WARNING: unmet direct dependencies detected for GENERIC_PHY_MIPI_DPHY
>   Depends on [n]: GENERIC_PHY [=n]
>   Selected by [y]:
>   - DRM_NWL_MIPI_DSI [=y] && DRM_BRIDGE [=y] && DRM [=y] && COMMON_CLK [=y] && OF [=y] && HAS_IOMEM [=y]
>   - DRM_SAMSUNG_DSIM [=y] && DRM [=y] && DRM_BRIDGE [=y] && COMMON_CLK [=y] && OF [=y] && HAS_IOMEM [=y]
>
> $ make CC=clang ARCH=arm64 LD=ld.lld CROSS_COMPILE=aarch64-linux-gnu- -j$(nproc)
>
> The kernel should have still compiled fine even despite the message above, right?
>
> Could you please take a look?

GENERIC_PHY_MIPI_DPHY was enabled to use
phy_mipi_dphy_get_default_config() which takes in the pixel clock,
bits-per-pixel, number of lanes and phy structure.  It applies a bunch
of math based on the info passed and fills in the structure, but that
function itself doesn't appear to be referencing phy code, so it's
likely safe.

I think this can be resolved by enabling GENERIC_PHY.  I just checked
linux-next and when I built the arm64 defconfig, it enables
GENERIC_PHY=y, so I don't think this is an issue.  I also checked the
multi_v7_defconfig for ARM and it also sets GENERIC_PHY=y for 32-bit
ARM people using some of the Exynos boards.

I don't know what version of Linux you're trying to build, but I can't
replicate your issue.

adam


>
> --
> Thank you!
> Aleksandr

Re: drivers/gpu/drm/bridge/samsung-dsim.c link error

[Randy Dunlap]

Hi--

On 8/3/23 08:24, Adam Ford wrote:
> On Thu, Aug 3, 2023 at 9:42 AM Aleksandr Nogikh <nogikh@google.com> wrote:
>>
>> Hello,
>>
>> We've been seing the following linker error on arm64 syzbot instances:
>>
>> ld.lld: error: undefined symbol: phy_mipi_dphy_get_default_config_for_hsclk
>>>>> referenced by samsung-dsim.c:731 (drivers/gpu/drm/bridge/samsung-dsim.c:731)
>>>>>               drivers/gpu/drm/bridge/samsung-dsim.o:(samsung_dsim_init) in archive vmlinux.a
>>
>> Steps to reproduce on the latest linux-next:
>>
>> $ git checkout next-20230803
>> $ wget -O '.config' 'https://raw.githubusercontent.com/google/syzkaller/master/dashboard/config/linux/upstream-arm64-kasan.config'
>> $ make CC=clang ARCH=arm64 LD=ld.lld CROSS_COMPILE=aarch64-linux-gnu- olddefconfig
>>
>> This also prints:
>>
>> WARNING: unmet direct dependencies detected for GENERIC_PHY_MIPI_DPHY
>>   Depends on [n]: GENERIC_PHY [=n]
>>   Selected by [y]:
>>   - DRM_NWL_MIPI_DSI [=y] && DRM_BRIDGE [=y] && DRM [=y] && COMMON_CLK [=y] && OF [=y] && HAS_IOMEM [=y]
>>   - DRM_SAMSUNG_DSIM [=y] && DRM [=y] && DRM_BRIDGE [=y] && COMMON_CLK [=y] && OF [=y] && HAS_IOMEM [=y]
>>
>> $ make CC=clang ARCH=arm64 LD=ld.lld CROSS_COMPILE=aarch64-linux-gnu- -j$(nproc)
>>
>> The kernel should have still compiled fine even despite the message above, right?

No. See drivers/Makefile:
obj-$(CONFIG_GENERIC_PHY)	+= phy/

so the drivers/phy/ subdir is only built when CONFIG_GENERIC_PHY is set,
but it's not set.

>> Could you please take a look?
> 
> GENERIC_PHY_MIPI_DPHY was enabled to use
> phy_mipi_dphy_get_default_config() which takes in the pixel clock,
> bits-per-pixel, number of lanes and phy structure.  It applies a bunch
> of math based on the info passed and fills in the structure, but that
> function itself doesn't appear to be referencing phy code, so it's
> likely safe.
> 
> I think this can be resolved by enabling GENERIC_PHY.  I just checked
> linux-next and when I built the arm64 defconfig, it enables
> GENERIC_PHY=y, so I don't think this is an issue.  I also checked the

defconfig doesn't matter in this case. The .config that was provided has:
# CONFIG_GENERIC_PHY is not set
CONFIG_GENERIC_PHY_MIPI_DPHY=y

but yes, selecting GENERIC_PHY (needed in 3 places) does fix the warnings
and build error.  2 instance in drm/bridge/Kconfig and one in
drm/bridge/cadence/Kconfig (found by inspection).



> multi_v7_defconfig for ARM and it also sets GENERIC_PHY=y for 32-bit
> ARM people using some of the Exynos boards.
> 
> I don't know what version of Linux you're trying to build, but I can't
> replicate your issue.

I had no problem replicating the kconfig warnings and build error.

-- 
~Randy

Re: drivers/gpu/drm/bridge/samsung-dsim.c link error

[Adam Ford]

On Thu, Aug 3, 2023 at 9:01 PM Randy Dunlap <rdunlap@infradead.org> wrote:
>
> Hi--
>
> On 8/3/23 08:24, Adam Ford wrote:
> > On Thu, Aug 3, 2023 at 9:42 AM Aleksandr Nogikh <nogikh@google.com> wrote:
> >>
> >> Hello,
> >>
> >> We've been seing the following linker error on arm64 syzbot instances:
> >>
> >> ld.lld: error: undefined symbol: phy_mipi_dphy_get_default_config_for_hsclk
> >>>>> referenced by samsung-dsim.c:731 (drivers/gpu/drm/bridge/samsung-dsim.c:731)
> >>>>>               drivers/gpu/drm/bridge/samsung-dsim.o:(samsung_dsim_init) in archive vmlinux.a
> >>
> >> Steps to reproduce on the latest linux-next:
> >>
> >> $ git checkout next-20230803
> >> $ wget -O '.config' 'https://raw.githubusercontent.com/google/syzkaller/master/dashboard/config/linux/upstream-arm64-kasan.config'
> >> $ make CC=clang ARCH=arm64 LD=ld.lld CROSS_COMPILE=aarch64-linux-gnu- olddefconfig
> >>
> >> This also prints:
> >>
> >> WARNING: unmet direct dependencies detected for GENERIC_PHY_MIPI_DPHY
> >>   Depends on [n]: GENERIC_PHY [=n]
> >>   Selected by [y]:
> >>   - DRM_NWL_MIPI_DSI [=y] && DRM_BRIDGE [=y] && DRM [=y] && COMMON_CLK [=y] && OF [=y] && HAS_IOMEM [=y]
> >>   - DRM_SAMSUNG_DSIM [=y] && DRM [=y] && DRM_BRIDGE [=y] && COMMON_CLK [=y] && OF [=y] && HAS_IOMEM [=y]
> >>
> >> $ make CC=clang ARCH=arm64 LD=ld.lld CROSS_COMPILE=aarch64-linux-gnu- -j$(nproc)
> >>
> >> The kernel should have still compiled fine even despite the message above, right?
>
> No. See drivers/Makefile:
> obj-$(CONFIG_GENERIC_PHY)       += phy/
>
> so the drivers/phy/ subdir is only built when CONFIG_GENERIC_PHY is set,
> but it's not set.
>
> >> Could you please take a look?
> >
> > GENERIC_PHY_MIPI_DPHY was enabled to use
> > phy_mipi_dphy_get_default_config() which takes in the pixel clock,
> > bits-per-pixel, number of lanes and phy structure.  It applies a bunch
> > of math based on the info passed and fills in the structure, but that
> > function itself doesn't appear to be referencing phy code, so it's
> > likely safe.
> >
> > I think this can be resolved by enabling GENERIC_PHY.  I just checked
> > linux-next and when I built the arm64 defconfig, it enables
> > GENERIC_PHY=y, so I don't think this is an issue.  I also checked the
>
> defconfig doesn't matter in this case. The .config that was provided has:
> # CONFIG_GENERIC_PHY is not set
> CONFIG_GENERIC_PHY_MIPI_DPHY=y
>

Where/how was the .config generated?

Are you building linux-next or something else?  The .config file
generated when I build the arm64 defconfig  show both enabled:

$ grep GENERIC_PHY .config
CONFIG_GENERIC_PHY=y
CONFIG_GENERIC_PHY_MIPI_DPHY=y


> but yes, selecting GENERIC_PHY (needed in 3 places) does fix the warnings
> and build error.  2 instance in drm/bridge/Kconfig and one in
> drm/bridge/cadence/Kconfig (found by inspection).
>
>
>
> > multi_v7_defconfig for ARM and it also sets GENERIC_PHY=y for 32-bit
> > ARM people using some of the Exynos boards.
> >
> > I don't know what version of Linux you're trying to build, but I can't
> > replicate your issue.
>
> I had no problem replicating the kconfig warnings and build error.

If you can replicate the problem, I'd suggest submitting a patch.

adam
>
> --
> ~Randy

Re: drivers/gpu/drm/bridge/samsung-dsim.c link error

[Randy Dunlap]

On 8/3/23 19:26, Adam Ford wrote:
> On Thu, Aug 3, 2023 at 9:01 PM Randy Dunlap <rdunlap@infradead.org> wrote:
>>
>> Hi--
>>
>> On 8/3/23 08:24, Adam Ford wrote:
>>> On Thu, Aug 3, 2023 at 9:42 AM Aleksandr Nogikh <nogikh@google.com> wrote:
>>>>
>>>> Hello,
>>>>
>>>> We've been seing the following linker error on arm64 syzbot instances:
>>>>
>>>> ld.lld: error: undefined symbol: phy_mipi_dphy_get_default_config_for_hsclk
>>>>>>> referenced by samsung-dsim.c:731 (drivers/gpu/drm/bridge/samsung-dsim.c:731)
>>>>>>>               drivers/gpu/drm/bridge/samsung-dsim.o:(samsung_dsim_init) in archive vmlinux.a
>>>>
>>>> Steps to reproduce on the latest linux-next:
>>>>
>>>> $ git checkout next-20230803
>>>> $ wget -O '.config' 'https://raw.githubusercontent.com/google/syzkaller/master/dashboard/config/linux/upstream-arm64-kasan.config'
>>>> $ make CC=clang ARCH=arm64 LD=ld.lld CROSS_COMPILE=aarch64-linux-gnu- olddefconfig
>>>>
>>>> This also prints:
>>>>
>>>> WARNING: unmet direct dependencies detected for GENERIC_PHY_MIPI_DPHY
>>>>   Depends on [n]: GENERIC_PHY [=n]
>>>>   Selected by [y]:
>>>>   - DRM_NWL_MIPI_DSI [=y] && DRM_BRIDGE [=y] && DRM [=y] && COMMON_CLK [=y] && OF [=y] && HAS_IOMEM [=y]
>>>>   - DRM_SAMSUNG_DSIM [=y] && DRM [=y] && DRM_BRIDGE [=y] && COMMON_CLK [=y] && OF [=y] && HAS_IOMEM [=y]
>>>>
>>>> $ make CC=clang ARCH=arm64 LD=ld.lld CROSS_COMPILE=aarch64-linux-gnu- -j$(nproc)
>>>>
>>>> The kernel should have still compiled fine even despite the message above, right?
>>
>> No. See drivers/Makefile:
>> obj-$(CONFIG_GENERIC_PHY)       += phy/
>>
>> so the drivers/phy/ subdir is only built when CONFIG_GENERIC_PHY is set,
>> but it's not set.
>>
>>>> Could you please take a look?
>>>
>>> GENERIC_PHY_MIPI_DPHY was enabled to use
>>> phy_mipi_dphy_get_default_config() which takes in the pixel clock,
>>> bits-per-pixel, number of lanes and phy structure.  It applies a bunch
>>> of math based on the info passed and fills in the structure, but that
>>> function itself doesn't appear to be referencing phy code, so it's
>>> likely safe.
>>>
>>> I think this can be resolved by enabling GENERIC_PHY.  I just checked
>>> linux-next and when I built the arm64 defconfig, it enables
>>> GENERIC_PHY=y, so I don't think this is an issue.  I also checked the
>>
>> defconfig doesn't matter in this case. The .config that was provided has:
>> # CONFIG_GENERIC_PHY is not set
>> CONFIG_GENERIC_PHY_MIPI_DPHY=y
>>
> 
> Where/how was the .config generated?
> 

Aleksandr posted a link to the config file above.

> Are you building linux-next or something else?  The .config file
> generated when I build the arm64 defconfig  show both enabled:

linux-next.


> $ grep GENERIC_PHY .config
> CONFIG_GENERIC_PHY=y
> CONFIG_GENERIC_PHY_MIPI_DPHY=y
> 

Yes, this is not a defconfig file.

> 
>> but yes, selecting GENERIC_PHY (needed in 3 places) does fix the warnings
>> and build error.  2 instance in drm/bridge/Kconfig and one in
>> drm/bridge/cadence/Kconfig (found by inspection).
>>
>>
>>
>>> multi_v7_defconfig for ARM and it also sets GENERIC_PHY=y for 32-bit
>>> ARM people using some of the Exynos boards.
>>>
>>> I don't know what version of Linux you're trying to build, but I can't
>>> replicate your issue.
>>
>> I had no problem replicating the kconfig warnings and build error.
> 
> If you can replicate the problem, I'd suggest submitting a patch.

Sure, I'll do that.

-- 
~Randy

Re: drivers/gpu/drm/bridge/samsung-dsim.c link error

[Adam Ford]

On Thu, Aug 3, 2023 at 9:37 PM Randy Dunlap <rdunlap@infradead.org> wrote:
>
>
>
> On 8/3/23 19:26, Adam Ford wrote:
> > On Thu, Aug 3, 2023 at 9:01 PM Randy Dunlap <rdunlap@infradead.org> wrote:
> >>
> >> Hi--
> >>
> >> On 8/3/23 08:24, Adam Ford wrote:
> >>> On Thu, Aug 3, 2023 at 9:42 AM Aleksandr Nogikh <nogikh@google.com> wrote:
> >>>>
> >>>> Hello,
> >>>>
> >>>> We've been seing the following linker error on arm64 syzbot instances:
> >>>>
> >>>> ld.lld: error: undefined symbol: phy_mipi_dphy_get_default_config_for_hsclk
> >>>>>>> referenced by samsung-dsim.c:731 (drivers/gpu/drm/bridge/samsung-dsim.c:731)
> >>>>>>>               drivers/gpu/drm/bridge/samsung-dsim.o:(samsung_dsim_init) in archive vmlinux.a
> >>>>
> >>>> Steps to reproduce on the latest linux-next:
> >>>>
> >>>> $ git checkout next-20230803
> >>>> $ wget -O '.config' 'https://raw.githubusercontent.com/google/syzkaller/master/dashboard/config/linux/upstream-arm64-kasan.config'
> >>>> $ make CC=clang ARCH=arm64 LD=ld.lld CROSS_COMPILE=aarch64-linux-gnu- olddefconfig
> >>>>
> >>>> This also prints:
> >>>>
> >>>> WARNING: unmet direct dependencies detected for GENERIC_PHY_MIPI_DPHY
> >>>>   Depends on [n]: GENERIC_PHY [=n]
> >>>>   Selected by [y]:
> >>>>   - DRM_NWL_MIPI_DSI [=y] && DRM_BRIDGE [=y] && DRM [=y] && COMMON_CLK [=y] && OF [=y] && HAS_IOMEM [=y]
> >>>>   - DRM_SAMSUNG_DSIM [=y] && DRM [=y] && DRM_BRIDGE [=y] && COMMON_CLK [=y] && OF [=y] && HAS_IOMEM [=y]
> >>>>
> >>>> $ make CC=clang ARCH=arm64 LD=ld.lld CROSS_COMPILE=aarch64-linux-gnu- -j$(nproc)
> >>>>
> >>>> The kernel should have still compiled fine even despite the message above, right?
> >>
> >> No. See drivers/Makefile:
> >> obj-$(CONFIG_GENERIC_PHY)       += phy/
> >>
> >> so the drivers/phy/ subdir is only built when CONFIG_GENERIC_PHY is set,
> >> but it's not set.
> >>
> >>>> Could you please take a look?
> >>>
> >>> GENERIC_PHY_MIPI_DPHY was enabled to use
> >>> phy_mipi_dphy_get_default_config() which takes in the pixel clock,
> >>> bits-per-pixel, number of lanes and phy structure.  It applies a bunch
> >>> of math based on the info passed and fills in the structure, but that
> >>> function itself doesn't appear to be referencing phy code, so it's
> >>> likely safe.
> >>>
> >>> I think this can be resolved by enabling GENERIC_PHY.  I just checked
> >>> linux-next and when I built the arm64 defconfig, it enables
> >>> GENERIC_PHY=y, so I don't think this is an issue.  I also checked the
> >>
> >> defconfig doesn't matter in this case. The .config that was provided has:
> >> # CONFIG_GENERIC_PHY is not set
> >> CONFIG_GENERIC_PHY_MIPI_DPHY=y
> >>
> >
> > Where/how was the .config generated?
> >
>
> Aleksandr posted a link to the config file above.

I get that, but I am not sure how this was generated.

>
> > Are you building linux-next or something else?  The .config file
> > generated when I build the arm64 defconfig  show both enabled:
>
> linux-next.
>
>
> > $ grep GENERIC_PHY .config
> > CONFIG_GENERIC_PHY=y
> > CONFIG_GENERIC_PHY_MIPI_DPHY=y
> >
>
> Yes, this is not a defconfig file.

I know, but it is a .config file that is generated from make defconfig
ARCH=arm64
>
> >
> >> but yes, selecting GENERIC_PHY (needed in 3 places) does fix the warnings
> >> and build error.  2 instance in drm/bridge/Kconfig and one in
> >> drm/bridge/cadence/Kconfig (found by inspection).
> >>
> >>
> >>
> >>> multi_v7_defconfig for ARM and it also sets GENERIC_PHY=y for 32-bit
> >>> ARM people using some of the Exynos boards.
> >>>
> >>> I don't know what version of Linux you're trying to build, but I can't
> >>> replicate your issue.
> >>
> >> I had no problem replicating the kconfig warnings and build error.
> >
> > If you can replicate the problem, I'd suggest submitting a patch.
>
> Sure, I'll do that.

Great!  thanks.

adam
>
> --
> ~Randy

Re: drivers/gpu/drm/bridge/samsung-dsim.c link error

[Randy Dunlap]

On 8/3/23 19:42, Adam Ford wrote:
> On Thu, Aug 3, 2023 at 9:37 PM Randy Dunlap <rdunlap@infradead.org> wrote:
>>
>>
>>
>> On 8/3/23 19:26, Adam Ford wrote:
>>> On Thu, Aug 3, 2023 at 9:01 PM Randy Dunlap <rdunlap@infradead.org> wrote:
>>>>
>>>> Hi--
>>>>
>>>> On 8/3/23 08:24, Adam Ford wrote:
>>>>> On Thu, Aug 3, 2023 at 9:42 AM Aleksandr Nogikh <nogikh@google.com> wrote:
>>>>>>
>>>>>> Hello,
>>>>>>
>>>>>> We've been seing the following linker error on arm64 syzbot instances:
>>>>>>
>>>>>> ld.lld: error: undefined symbol: phy_mipi_dphy_get_default_config_for_hsclk
>>>>>>>>> referenced by samsung-dsim.c:731 (drivers/gpu/drm/bridge/samsung-dsim.c:731)
>>>>>>>>>               drivers/gpu/drm/bridge/samsung-dsim.o:(samsung_dsim_init) in archive vmlinux.a
>>>>>>
>>>>>> Steps to reproduce on the latest linux-next:
>>>>>>
>>>>>> $ git checkout next-20230803
>>>>>> $ wget -O '.config' 'https://raw.githubusercontent.com/google/syzkaller/master/dashboard/config/linux/upstream-arm64-kasan.config'
>>>>>> $ make CC=clang ARCH=arm64 LD=ld.lld CROSS_COMPILE=aarch64-linux-gnu- olddefconfig
>>>>>>
>>>>>> This also prints:
>>>>>>
>>>>>> WARNING: unmet direct dependencies detected for GENERIC_PHY_MIPI_DPHY
>>>>>>   Depends on [n]: GENERIC_PHY [=n]
>>>>>>   Selected by [y]:
>>>>>>   - DRM_NWL_MIPI_DSI [=y] && DRM_BRIDGE [=y] && DRM [=y] && COMMON_CLK [=y] && OF [=y] && HAS_IOMEM [=y]
>>>>>>   - DRM_SAMSUNG_DSIM [=y] && DRM [=y] && DRM_BRIDGE [=y] && COMMON_CLK [=y] && OF [=y] && HAS_IOMEM [=y]
>>>>>>
>>>>>> $ make CC=clang ARCH=arm64 LD=ld.lld CROSS_COMPILE=aarch64-linux-gnu- -j$(nproc)
>>>>>>
>>>>>> The kernel should have still compiled fine even despite the message above, right?
>>>>
>>>> No. See drivers/Makefile:
>>>> obj-$(CONFIG_GENERIC_PHY)       += phy/
>>>>
>>>> so the drivers/phy/ subdir is only built when CONFIG_GENERIC_PHY is set,
>>>> but it's not set.
>>>>
>>>>>> Could you please take a look?
>>>>>
>>>>> GENERIC_PHY_MIPI_DPHY was enabled to use
>>>>> phy_mipi_dphy_get_default_config() which takes in the pixel clock,
>>>>> bits-per-pixel, number of lanes and phy structure.  It applies a bunch
>>>>> of math based on the info passed and fills in the structure, but that
>>>>> function itself doesn't appear to be referencing phy code, so it's
>>>>> likely safe.
>>>>>
>>>>> I think this can be resolved by enabling GENERIC_PHY.  I just checked
>>>>> linux-next and when I built the arm64 defconfig, it enables
>>>>> GENERIC_PHY=y, so I don't think this is an issue.  I also checked the
>>>>
>>>> defconfig doesn't matter in this case. The .config that was provided has:
>>>> # CONFIG_GENERIC_PHY is not set
>>>> CONFIG_GENERIC_PHY_MIPI_DPHY=y
>>>>
>>>
>>> Where/how was the .config generated?
>>>
>>
>> Aleksandr posted a link to the config file above.
> 
> I get that, but I am not sure how this was generated.
> 

Nor am I. Alexsandr can hopefully tell us.

>>
>>> Are you building linux-next or something else?  The .config file
>>> generated when I build the arm64 defconfig  show both enabled:
>>
>> linux-next.
>>
>>
>>> $ grep GENERIC_PHY .config
>>> CONFIG_GENERIC_PHY=y
>>> CONFIG_GENERIC_PHY_MIPI_DPHY=y
>>>
>>
>> Yes, this is not a defconfig file.
> 
> I know, but it is a .config file that is generated from make defconfig
> ARCH=arm64
>>

Not necessarily. It could be generated by 'make randconfig'.

>>>
>>>> but yes, selecting GENERIC_PHY (needed in 3 places) does fix the warnings
>>>> and build error.  2 instance in drm/bridge/Kconfig and one in
>>>> drm/bridge/cadence/Kconfig (found by inspection).
>>>>
>>>>
>>>>
>>>>> multi_v7_defconfig for ARM and it also sets GENERIC_PHY=y for 32-bit
>>>>> ARM people using some of the Exynos boards.
>>>>>
>>>>> I don't know what version of Linux you're trying to build, but I can't
>>>>> replicate your issue.
>>>>
>>>> I had no problem replicating the kconfig warnings and build error.
>>>
>>> If you can replicate the problem, I'd suggest submitting a patch.
>>
>> Sure, I'll do that.
> 
> Great!  thanks.
> 
> adam
>>
>> --
>> ~Randy

-- 
~Randy

Re: drivers/gpu/drm/bridge/samsung-dsim.c link error

[Aleksandr Nogikh]

On Fri, Aug 4, 2023 at 4:47 AM Randy Dunlap <rdunlap@infradead.org> wrote:
>
> On 8/3/23 19:42, Adam Ford wrote:
> > On Thu, Aug 3, 2023 at 9:37 PM Randy Dunlap <rdunlap@infradead.org> wrote:
> >>
> >> On 8/3/23 19:26, Adam Ford wrote:
> >>> Where/how was the .config generated?
> >>>
> >>
> >> Aleksandr posted a link to the config file above.
> >
> > I get that, but I am not sure how this was generated.
> >
>
> Nor am I. Alexsandr can hopefully tell us.

We take a defconfig and apply a number of modifications on top of it
(*). Some configs are enabled (e.g. various sanitizers), some are
disabled (e.g. a number of heavy subsystems are disabled for instances
that run on qemu w/o hardware acceleration).

We rely heavily on olddefconfig to detect inconsistencies during
config generation (we regenerate them manually once in a while and the
tool makes sure our changes do not contradict KConfigs) and to
automatically correct inconsistencies when a kernel is being
(re-)built (there's no other way -- something constantly changes in
the mainline tree and it's impossible to keep track of it all
manually).

In this particular case, we indeed disabled CONFIG_GENERIC_PHY, but
left other dependent configs enabled and `make olddefconfig` could
unfortunately neither help us detect the problem nor resolve it during
the build :(

(*) FWIW here's a doc for reference:
https://github.com/google/syzkaller/blob/master/dashboard/config/linux/README.md

>
> >>
> >>> Are you building linux-next or something else?  The .config file
> >>> generated when I build the arm64 defconfig  show both enabled:
> >>
> >> linux-next.
> >>
> >>
> >>> $ grep GENERIC_PHY .config
> >>> CONFIG_GENERIC_PHY=y
> >>> CONFIG_GENERIC_PHY_MIPI_DPHY=y
> >>>
> >>
> >> Yes, this is not a defconfig file.
> >
> > I know, but it is a .config file that is generated from make defconfig
> > ARCH=arm64
> >>
>
> Not necessarily. It could be generated by 'make randconfig'.
>
> >>>
> >>>> but yes, selecting GENERIC_PHY (needed in 3 places) does fix the warnings
> >>>> and build error.  2 instance in drm/bridge/Kconfig and one in
> >>>> drm/bridge/cadence/Kconfig (found by inspection).
> >>>>
> >>>> I had no problem replicating the kconfig warnings and build error.
> >>>
> >>> If you can replicate the problem, I'd suggest submitting a patch.
> >>
> >> Sure, I'll do that.
> >
> > Great!  thanks.

I see the patch has already been sent. Thank you very much!

> >
> > adam
> >>
> >> --
> >> ~Randy
>
> --
> ~Randy