[PATCH v6 3/5] fbdev: Disable sysfb device registration when removing conflicting FBs

[Javier Martinez Canillas]

Hello Zack,

On 6/16/22 21:29, Zack Rusin wrote:
> On Tue, 2022-06-07 at 20:23 +0200, Javier Martinez Canillas wrote:
>> The platform devices registered by sysfb match with firmware-based DRM or
>> fbdev drivers, that are used to have early graphics using a framebuffer
>> provided by the system firmware.
>>

[snip]

> 
> Hi, Javier.
> 
> This change broke arm64 with vmwgfx. We get a kernel oops at boot (let me know if
> you'd like .config or just have us test something directly for you):
>

Yes please share your .config and I'll try to reproduce on an arm64 machine.

> 
>  Unable to handle kernel NULL pointer dereference at virtual address
> 0000000000000008
>  Mem abort info:
>    ESR = 0x96000004
>    EC = 0x25: DABT (current EL), IL = 32 bits
>    SET = 0, FnV = 0
>    EA = 0, S1PTW = 0
>    FSC = 0x04: level 0 translation fault
>  Data abort info:
>    ISV = 0, ISS = 0x00000004
>    CM = 0, WnR = 0
>  user pgtable: 4k pages, 48-bit VAs, pgdp=00000001787ee000
>  [0000000000000008] pgd=0000000000000000, p4d=0000000000000000
>  Internal error: Oops: 96000004 [#1] SMP
>  Modules linked in: vmwgfx(+) e1000e(+) nvme ahci(+) xhci_pci drm_ttm_helper ttm
> sha256_arm64 sha1_ce nvme_core xhci_pci_renesas aes_neon_bs aes_neon_blk aes>
>  CPU: 3 PID: 215 Comm: systemd-udevd Tainted: G     U            5.18.0-rc5-vmwgfx
> #12

I'm confused, your kernel version seems to be 5.18.0-rc5 but this patch
is only in drm-misc-next now and will land in 5.20...

Did you backport it? Can you please try to reproduce with latest drm-tip ?

-- 
Best regards,

Javier Martinez Canillas
Linux Engineering
Red Hat