Recently, the driver introduce DML2 for future ASIC support. But, some ASIC's hubbub pointer isn't set after calling dce120_create_resource_pool(). Before setting get_dchub_ref_freq(), these hubbub pointer is null, it cause the below null pointer issue. So add check whether res_pool->hubbub to fix it. BUG: kernel NULL pointer dereference, address: 0000000000000000 RIP: 0010:dc_create_resource_pool+0xc1/0x2c0 [amdgpu] Call Trace: <TASK> ? show_regs.cold+0x1a/0x1f ? __die_body+0x20/0x70 ? __die+0x2b/0x37 ? page_fault_oops+0x136/0x2c0 ? do_user_addr_fault+0x303/0x660 ? exc_page_fault+0x77/0x170 ? asm_exc_page_fault+0x27/0x30 ? dc_create_resource_pool+0xc1/0x2c0 [amdgpu] ? dc_create_resource_pool+0x243/0x2c0 [amdgpu] dc_create+0x23f/0x6b0 [amdgpu] ? dmi_matches+0xa3/0x200 amdgpu_dm_init+0x2bd/0x22a0 [amdgpu] Fixes: 50003b5aa5f5 ("drm/amd/display: Introduce DML2") Signed-off-by: Bob Zhou <bob.zhou@xxxxxxx> --- drivers/gpu/drm/amd/display/dc/core/dc_resource.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_resource.c b/drivers/gpu/drm/amd/display/dc/core/dc_resource.c index a93db60fe4d9..9cc7a001f9a1 100644 --- a/drivers/gpu/drm/amd/display/dc/core/dc_resource.c +++ b/drivers/gpu/drm/amd/display/dc/core/dc_resource.c @@ -319,10 +319,12 @@ struct resource_pool *dc_create_resource_pool(struct dc *dc, res_pool->ref_clocks.xtalin_clock_inKhz; res_pool->ref_clocks.dchub_ref_clock_inKhz = res_pool->ref_clocks.xtalin_clock_inKhz; - if ((res_pool->hubbub->funcs->get_dchub_ref_freq)) - res_pool->hubbub->funcs->get_dchub_ref_freq(res_pool->hubbub, - res_pool->ref_clocks.dccg_ref_clock_inKhz, - &res_pool->ref_clocks.dchub_ref_clock_inKhz); + if (res_pool->hubbub) + if (res_pool->hubbub->funcs->get_dchub_ref_freq) + res_pool->hubbub->funcs->get_dchub_ref_freq( + res_pool->hubbub, + res_pool->ref_clocks.dccg_ref_clock_inKhz, + &res_pool->ref_clocks.dchub_ref_clock_inKhz); } else ASSERT_CRITICAL(false); } -- 2.34.1