Re: [PATCH 1/4] drm/msm: Fix bootup splat with separate_gpu_drm modparam

[Akhil P Oommen <akhilpo@oss.qualcomm.com>]

On 9/2/2025 5:57 PM, Dmitry Baryshkov wrote:
> On Tue, Sep 02, 2025 at 05:20:00PM +0530, Akhil P Oommen wrote:
>> The drm_gem_for_each_gpuvm_bo() call from lookup_vma() accesses
>> drm_gem_obj.gpuva.list, which is not initialized when the drm driver
>> does not support DRIVER_GEM_GPUVA feature. Enable it for msm_kms
>> drm driver to fix the splat seen when msm.separate_gpu_drm=1 modparam
>> is set:
>>
>> [    9.506020] Unable to handle kernel paging request at virtual address fffffffffffffff0
>> [    9.523160] Mem abort info:
>> [    9.523161]   ESR = 0x0000000096000006
>> [    9.523163]   EC = 0x25: DABT (current EL), IL = 32 bits
>> [    9.523165]   SET = 0, FnV = 0
>> [    9.523166]   EA = 0, S1PTW = 0
>> [    9.523167]   FSC = 0x06: level 2 translation fault
>> [    9.523169] Data abort info:
>> [    9.523170]   ISV = 0, ISS = 0x00000006, ISS2 = 0x00000000
>> [    9.523171]   CM = 0, WnR = 0, TnD = 0, TagAccess = 0
>> [    9.523172]   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
>> [    9.523174] swapper pgtable: 4k pages, 48-bit VAs, pgdp=0000000ad370f000
>> [    9.523176] [fffffffffffffff0] pgd=0000000000000000, p4d=0000000ad4787403, pud=0000000ad4788403, pmd=0000000000000000
>> [    9.523184] Internal error: Oops: 0000000096000006 [#1]  SMP
>> [    9.592968] CPU: 9 UID: 0 PID: 448 Comm: (udev-worker) Not tainted 6.17.0-rc4-assorted-fix-00005-g0e9bb53a2282-dirty #3 PREEMPT
>> [    9.592970] Hardware name: Qualcomm CRD, BIOS 6.0.240718.BOOT.MXF.2.4-00515-HAMOA-1 07/18/2024
>> [    9.592971] pstate: a1400005 (NzCv daif +PAN -UAO -TCO +DIT -SSBS BTYPE=--)
>> [    9.592973] pc : lookup_vma+0x28/0xe0 [msm]
>> [    9.592996] lr : get_vma_locked+0x2c/0x128 [msm]
>> [    9.763632] sp : ffff800082dab460
>> [    9.763666] Call trace:
>> [    9.763668]  lookup_vma+0x28/0xe0 [msm] (P)
>> [    9.763688]  get_vma_locked+0x2c/0x128 [msm]
>> [    9.763706]  msm_gem_get_and_pin_iova_range+0x68/0x11c [msm]
>> [    9.763723]  msm_gem_get_and_pin_iova+0x18/0x24 [msm]
>> [    9.763740]  msm_fbdev_driver_fbdev_probe+0xd0/0x258 [msm]
>> [    9.763760]  __drm_fb_helper_initial_config_and_unlock+0x288/0x528 [drm_kms_helper]
>> [    9.763771]  drm_fb_helper_initial_config+0x44/0x54 [drm_kms_helper]
>> [    9.763779]  drm_fbdev_client_hotplug+0x84/0xd4 [drm_client_lib]
>> [    9.763782]  drm_client_register+0x58/0x9c [drm]
>> [    9.763806]  drm_fbdev_client_setup+0xe8/0xcf0 [drm_client_lib]
>> [    9.763809]  drm_client_setup+0xb4/0xd8 [drm_client_lib]
>> [    9.763811]  msm_drm_kms_post_init+0x2c/0x3c [msm]
>> [    9.763830]  msm_drm_init+0x1a8/0x22c [msm]
>> [    9.763848]  msm_drm_bind+0x30/0x3c [msm]
>> [    9.919273]  try_to_bring_up_aggregate_device+0x168/0x1d4
>> [    9.919283]  __component_add+0xa4/0x170
>> [    9.919286]  component_add+0x14/0x20
>> [    9.919288]  msm_dp_display_probe_tail+0x4c/0xac [msm]
>> [    9.919315]  msm_dp_auxbus_done_probe+0x14/0x20 [msm]
>> [    9.919335]  dp_aux_ep_probe+0x4c/0xf0 [drm_dp_aux_bus]
>> [    9.919341]  really_probe+0xbc/0x298
>> [    9.919345]  __driver_probe_device+0x78/0x12c
>> [    9.919348]  driver_probe_device+0x40/0x160
>> [    9.919350]  __driver_attach+0x94/0x19c
>> [    9.919353]  bus_for_each_dev+0x74/0xd4
>> [    9.919355]  driver_attach+0x24/0x30
>> [    9.919358]  bus_add_driver+0xe4/0x208
>> [    9.919360]  driver_register+0x60/0x128
>> [    9.919363]  __dp_aux_dp_driver_register+0x24/0x30 [drm_dp_aux_bus]
>> [    9.919365]  atana33xc20_init+0x20/0x1000 [panel_samsung_atna33xc20]
>> [    9.919370]  do_one_initcall+0x6c/0x1b0
>> [    9.919374]  do_init_module+0x58/0x234
>> [    9.919377]  load_module+0x19cc/0x1bd4
>> [    9.919380]  init_module_from_file+0x84/0xc4
>> [    9.919382]  __arm64_sys_finit_module+0x1b8/0x2cc
>> [    9.919384]  invoke_syscall+0x48/0x110
>> [    9.919389]  el0_svc_common.constprop.0+0xc8/0xe8
>> [    9.919393]  do_el0_svc+0x20/0x2c
>> [    9.919396]  el0_svc+0x34/0xf0
>> [    9.919401]  el0t_64_sync_handler+0xa0/0xe4
>> [    9.919403]  el0t_64_sync+0x198/0x19c
>> [    9.919407] Code: eb0000bf 54000480 d100a003 aa0303e2 (f8418c44)
>> [    9.919410] ---[ end trace 0000000000000000 ]---
> 
> Nit: usually you can drop timestamps from the kernel log.

Missed my eyes. Will update in v2.

-Akhil.

> 
>>
>> Fixes: 217ed15bd399 ("drm/msm: enable separate binding of GPU and display devices")
>> Signed-off-by: Akhil P Oommen <akhilpo@oss.qualcomm.com>
>> ---
>>  drivers/gpu/drm/msm/msm_drv.c | 1 +
>>  1 file changed, 1 insertion(+)
>>
> 
> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
> 
>