On Tue, Aug 29, 2023 at 03:30:24PM +0200, Michael Walle wrote: > Hi Nícolas, > > > > But the real reason I've enabled it was because I'll get an kernel > > > oops otherwise. I thought it might be some quirk that you'll need > > > both, > > > because eDP will register even if theres no display - as you've > > > mentioned below. > > > > > > Here's the splat: > > > [ 3.237064] mediatek-drm mediatek-drm.10.auto: bound > > > 1c110000.vpp-merge > > > (ops mtk_disp_merge_component_ops) > > > [ 3.238274] mediatek-drm mediatek-drm.8.auto: Not creating crtc 0 > > > because > > > component 8 is disabled or missing > > > [ 3.239504] mediatek-drm mediatek-drm.8.auto: Not creating crtc 0 > > > because > > > component 9 is disabled or missing > > > [ 3.240741] Unable to handle kernel NULL pointer dereference at > > > virtual > > > address 00000000000004a0 > > > [ 3.241841] Mem abort info: > > > [ 3.242192] ESR = 0x0000000096000004 > > > [ 3.242662] EC = 0x25: DABT (current EL), IL = 32 bits > > > [ 3.243328] SET = 0, FnV = 0 > > > [ 3.243710] EA = 0, S1PTW = 0 > > > [ 3.244104] FSC = 0x04: level 0 translation fault > > > [ 3.244717] Data abort info: > > > [ 3.245078] ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000 > > > [ 3.245765] CM = 0, WnR = 0, TnD = 0, TagAccess = 0 > > > [ 3.246398] GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 > > > [ 3.247063] [00000000000004a0] user address but active_mm is > > > swapper > > > [ 3.247860] Internal error: Oops: 0000000096000004 [#1] SMP > > > [ 3.248559] Modules linked in: > > > [ 3.248945] CPU: 4 PID: 11 Comm: kworker/u16:0 Not tainted > > > 6.5.0-rc7-next-20230821+ #2225 > > > [ 3.249970] Hardware name: Kontron 3.5"-SBC-i1200 (DT) > > > [ 3.250614] Workqueue: events_unbound deferred_probe_work_func > > > [ 3.251347] pstate: 60400009 (nZCv daif +PAN -UAO -TCO -DIT -SSBS > > > BTYPE=--) > > > [ 3.252220] pc : mtk_drm_crtc_dma_dev_get+0x8/0x18 > > > [ 3.252824] lr : mtk_drm_bind+0x458/0x558 > > > [ 3.253326] sp : ffff800082b23a20 > > > [ 3.253741] x29: ffff800082b23a20 x28: ffff000002c78880 x27: > > > ffff8000816466d0 > > > [ 3.254635] x26: ffff000002c6f010 x25: 0000000000000003 x24: > > > 0000000000000000 > > > [ 3.255529] x23: ffff000002c78880 x22: 0000000000000002 x21: > > > 0000000000000000 > > > [ 3.256423] x20: ffff000006516800 x19: ffff000002c78880 x18: > > > ffffffffffffffff > > > [ 3.257317] x17: 6f63206573756163 x16: 6562203020637472 x15: > > > 6320676e69746165 > > > [ 3.258211] x14: 726320746f4e203a x13: 676e697373696d20 x12: > > > 726f2064656c6261 > > > [ 3.259106] x11: 7369642073692039 x10: ffff80008275c0c0 x9 : > > > ffff80008091ebf8 > > > [ 3.260000] x8 : 00000000ffffefff x7 : ffff80008275c0c0 x6 : > > > 80000000fffff000 > > > [ 3.260895] x5 : 000000000000bff4 x4 : 0000000000000000 x3 : > > > ffff000006516ae0 > > > [ 3.261789] x2 : ffff000006516ae0 x1 : 0000000000000000 x0 : > > > 0000000000000000 > > > [ 3.262684] Call trace: > > > [ 3.262991] mtk_drm_crtc_dma_dev_get+0x8/0x18 > > > [ 3.263549] try_to_bring_up_aggregate_device+0x16c/0x1e0 > > > [ 3.264227] __component_add+0xac/0x180 > > > [ 3.264708] component_add+0x1c/0x30 > > > [ 3.265158] mtk_disp_rdma_probe+0x17c/0x270 > > > [ 3.265695] platform_probe+0x70/0xd0 > > > [ 3.266155] really_probe+0x150/0x2c0 > > > [ 3.266615] __driver_probe_device+0x80/0x140 > > > [ 3.267162] driver_probe_device+0x44/0x170 > > > [ 3.267687] __device_attach_driver+0xc0/0x148 > > > [ 3.268245] bus_for_each_drv+0x88/0xf0 > > > [ 3.268727] __device_attach+0xa4/0x198 > > > [ 3.269208] device_initial_probe+0x1c/0x30 > > > [ 3.269732] bus_probe_device+0xb4/0xc0 > > > [ 3.270214] deferred_probe_work_func+0x90/0xd0 > > > [ 3.270783] process_one_work+0x144/0x3a0 > > > [ 3.271289] worker_thread+0x2ac/0x4b8 > > > [ 3.271761] kthread+0xec/0xf8 > > > [ 3.272145] ret_from_fork+0x10/0x20 > > > [ 3.272597] Code: 814f7858 ffff8000 aa1e03e9 d503201f (f9425000) > > > [ 3.273361] ---[ end trace 0000000000000000 ]--- > > > > I tried reproducing this on mt8192-asurada-spherion and > > mt8195-cherry-tomato but > > wasn't able to. However, I did see another issue > > Yeah sorry, I tried to reproduce my initial oops but messed my DT up > and ended up with no path enabled at all. No worries, thanks for sending fixes for both! > [..] > > The mtk-dpi driver populates its encoder's possible_crtcs from the > > result of > > mtk_drm_find_possible_crtc_by_comp(), and this function assumes the CRTC > > for the > > main path will always have ID 0, and the external path ID 1, but when > > the > > main path components are disabled, the external path CRTC becomes the > > one with > > ID 0. > > > > So we'd need to make that function return the crtc id dynamically based > > on > > whether the components for each path are enabled or not. > > > > With that function hacked to force the right crtc ID, I was able to have > > a > > working external DP, with the eDP pipeline disabled on both mt8192 and > > mt8195. > > Thanks for the hint, where to look at. > > While digging through the code I realized that all the outputs and pipelines > are harcoded. Doh. For all the mediatek SoCs. Looks like major restriction > to > me. E.g. there is also DSI and HDMI output on the mt8195. I looked at the > downstream linux and there, the output is not part of the pipeline. Are you > aware of any work in that direction? I'm not sure I get what output and pipelines are hardcoded that you're referring to (besides the one in the mtk-dsi/dpi driver that you already sent the patch fixing). And I'm not familiar with the DSI and HDMI output support on MT8195, so I can't help with that. Thanks, Nícolas
