Re: [PATCH 00/11] drm: bridge: Add Samsung MIPI DSIM bridge

[Adam Ford <aford173@gmail.com>]

On Mon, Apr 11, 2022 at 11:25 AM Marek Szyprowski
<m.szyprowski@samsung.com> wrote:
>
> On 11.04.2022 16:39, Adam Ford wrote:
> > On Mon, Apr 11, 2022 at 8:56 AM Marek Szyprowski
> > <m.szyprowski@samsung.com> wrote:
> >> On 08.04.2022 18:20, Jagan Teki wrote:
> >>> This series supports common bridge support for Samsung MIPI DSIM
> >>> which is used in Exynos and i.MX8MM SoC's.
> >>>
> >>> Previous RFC can be available here [1].
> >>>
> >>> The final bridge supports both the Exynos and i.MX8MM DSI devices.
> >>>
> >>> On, summary this patch-set break the entire DSIM driver into
> >>> - platform specific glue code for platform ops, component_ops.
> >>> - common bridge driver which handle platform glue init and invoke.
> >>>
> >>> Patch 0000:   Samsung DSIM bridge
> >>>
> >>> Patch 0001:   platform init flag via driver_data
> >>>
> >>> Patch 0002/9:   bridge fixes, atomic API's
> >>>
> >>> Patch 0010:   document fsl,imx8mm-mipi-dsim
> >>>
> >>> Patch 0011:   add i.MX8MM DSIM support
> >>>
> >>> Tested in Engicam i.Core MX8M Mini SoM.
> >>>
> >>> Anyone interested, please have a look on this repo [2]

I attempted to build your newer repo, but I get build errors:

~/src/linux-opendev$ make Image modules ARCH=arm64
CROSS_COMPILE=aarch64-linux-gnu- -j8
  CALL    scripts/atomic/check-atomics.sh
  CALL    scripts/checksyscalls.sh
  CHK     include/generated/compile.h
  MODPOST modules-only.symvers
ERROR: modpost: "dsi_driver" [drivers/gpu/drm/exynos/exynosdrm.ko] undefined!
make[1]: *** [scripts/Makefile.modpost:134: modules-only.symvers] Error 1
make[1]: *** Deleting file 'modules-only.symvers'
make: *** [Makefile:1746: modules] Error 2

I'm using gcc version 11.2.0 (Ubuntu 11.2.0-17ubuntu1) part of the
ubuntu 22.04 beta.  I know it's beta, so it might be buggy, but I
expect GCC 11.2 to be stable.

I'm going to keep investigating.  If I find a fix, I'll send you a
private message with the patch attached to avoid spamming everyone.

adam

> >>>
> >>> [2] https://protect2.fireeye.com/v1/url?k=930e329a-f28527b5-930fb9d5-74fe485cbfe7-b0c53e2d688ddbc5&q=1&e=e6aa727d-5ae2-4ca5-bff3-7f62d8fae87e&u=https%3A%2F%2Fgithub.com%2Fopenedev%2Fkernel%2Ftree%2Fimx8mm-dsi-v1
> >>> [1] https://lore.kernel.org/linux-arm-kernel/YP2j9k5SrZ2%2Fo2%2F5@ravnborg.org/T/
> >>>
> >>> Any inputs?
> >> I wanted to test this on the Exynos, but I wasn't able to find what base
> >> should I apply this patchset. I've tried linux-next as well as
> >> 95a2441e4347 ("drm: exynos: dsi: Switch to atomic funcs").
> >>
> >> Please note that pointing a proper base for the patchset is really
> >> essential if you really want others to test it.
> > Can you clone his repo and test that?  He posted it above.  I was
> > going to clone it at some point this week to give it a try.
>
> Okay, my fault. I've missed that.
>
> There is a trivial compilation issue,
> drivers/gpu/drm/exynos/exynos_drm_dsi.c lacks "#include
> <linux/gpio/consumer.h>" after conversion. Besides that, it simply nukes
> on the simplest Exynos setup (exynos4210-trats) during the initialization:
>
> [drm] Exynos DRM: using 11c00000.fimd device for DMA mapping operations
> exynos-drm exynos-drm: bound 11c00000.fimd (ops fimd_component_ops)
> 8<--- cut here ---
> Unable to handle kernel NULL pointer dereference at virtual address 00000048
> [00000048] *pgd=00000000
> Internal error: Oops: 5 [#1] PREEMPT SMP ARM
> Modules linked in:
> CPU: 0 PID: 1 Comm: swapper/0 Not tainted
> 5.17.0-rc2-00577-g22e968113668-dirty #11635
> Hardware name: Samsung Exynos (Flattened Device Tree)
> PC is at exynos_dsi_bind+0x14/0x3c
> LR is at component_bind_all+0x130/0x290
> pc : [<c06924e0>]    lr : [<c06b0f6c>]    psr: 60000113
> sp : c1cafcb8  ip : 00000002  fp : c0f4a53c
> r10: c135e6a8  r9 : c1efd800  r8 : 00000000
> r7 : c26d2100  r6 : c2c69fc0  r5 : 00000018  r4 : 00000000
> r3 : c06924cc  r2 : 00000002  r1 : 00000000  r0 : c1efd800
> Flags: nZCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment none
> Control: 10c5387d  Table: 4000404a  DAC: 00000051
> Register r0 information: slab kmalloc-2k start c1efd800 pointer offset 0
> size 2048
> Register r1 information: NULL pointer
> Register r2 information: non-paged memory
> Register r3 information: non-slab/vmalloc memory
> Register r4 information: NULL pointer
> Register r5 information: non-paged memory
> Register r6 information: slab kmalloc-64 start c2c69fc0 pointer offset 0
> size 64
> Register r7 information: slab kmalloc-64 start c26d2100 pointer offset 0
> size 64
> Register r8 information: NULL pointer
> Register r9 information: slab kmalloc-2k start c1efd800 pointer offset 0
> size 2048
> Register r10 information: non-slab/vmalloc memory
> Register r11 information: non-slab/vmalloc memory
> Register r12 information: non-paged memory
> Process swapper/0 (pid: 1, stack limit = 0x(ptrval))
> Stack: (0xc1cafcb8 to 0xc1cb0000)
> ...
>   exynos_dsi_bind from component_bind_all+0x130/0x290
>   component_bind_all from exynos_drm_bind+0xe8/0x194
>   exynos_drm_bind from try_to_bring_up_master+0x208/0x2d0
>   try_to_bring_up_master from component_master_add_with_match+0xd0/0x104
>   component_master_add_with_match from exynos_drm_platform_probe+0xe8/0x118
>   exynos_drm_platform_probe from platform_probe+0x80/0xc0
>   platform_probe from really_probe+0xfc/0x440
>   really_probe from __driver_probe_device+0xa4/0x204
>   __driver_probe_device from driver_probe_device+0x34/0xd4
>   driver_probe_device from __driver_attach+0x114/0x184
>   __driver_attach from bus_for_each_dev+0x64/0xb0
>   bus_for_each_dev from bus_add_driver+0x170/0x20c
>   bus_add_driver from driver_register+0x78/0x10c
>   driver_register from exynos_drm_init+0xe0/0x14c
>   exynos_drm_init from do_one_initcall+0x6c/0x3a4
>   do_one_initcall from kernel_init_freeable+0x1c4/0x214
>   kernel_init_freeable from kernel_init+0x18/0x12c
>   kernel_init from ret_from_fork+0x14/0x2c
> Exception stack(0xc1caffb0 to 0xc1cafff8)
> ffa0:                                     00000000 00000000 00000000
> 00000000
> ffc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000
> 00000000
> ffe0: 00000000 00000000 00000000 00000000 00000013 00000000
> Code: e5904040 e1a00002 e3a02002 e1a01004 (e5945048)
> ---[ end trace 0000000000000000 ]---
> Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b
> CPU1: stopping
> CPU: 1 PID: 0 Comm: swapper/1 Tainted: G      D
> 5.17.0-rc2-00577-g22e968113668-dirty #11635
> Hardware name: Samsung Exynos (Flattened Device Tree)
>   unwind_backtrace from show_stack+0x10/0x14
>   show_stack from dump_stack_lvl+0x58/0x70
>   dump_stack_lvl from do_handle_IPI+0x2ec/0x36c
>   do_handle_IPI from ipi_handler+0x18/0x20
>   ipi_handler from handle_percpu_devid_irq+0xd0/0x394
>   handle_percpu_devid_irq from generic_handle_domain_irq+0x44/0x88
>   generic_handle_domain_irq from gic_handle_irq+0x88/0xac
>   gic_handle_irq from generic_handle_arch_irq+0x58/0x78
>   generic_handle_arch_irq from __irq_svc+0x54/0x88
> Exception stack(0xc1cd1f48 to 0xc1cd1f90)
> 1f40:                   00000001 c0eff5a4 00000001 c011ca80 c1208f0c
> c1353420
> 1f60: 00000000 c1d8d000 00000000 c0f34234 c1d8d000 00000000 c0eeee98
> c1cd1f98
> 1f80: c0109144 c0109148 20000013 ffffffff
>   __irq_svc from arch_cpu_idle+0x40/0x44
>   arch_cpu_idle from default_idle_call+0x74/0x2c4
>   default_idle_call from do_idle+0x1cc/0x284
>   do_idle from cpu_startup_entry+0x18/0x1c
>   cpu_startup_entry from 0x401018b4
> ---[ end Kernel panic - not syncing: Attempted to kill init!
> exitcode=0x0000000b ]---
>
>
> I will try to take a look into this later in the evening.
>
>
> Best regards
> --
> Marek Szyprowski, PhD
> Samsung R&D Institute Poland
>