Re: [REGRESSION] [BISECTED] drm/sun4i: hdmi: No HDMI output with BananaPI M1 on 6.9

[Michael Klein]

On Mon, Jun 02, 2025 at 08:40:20PM +0200, Michael Klein wrote:
> On Mon, Jun 02, 2025 at 11:55:44AM +0200, Maxime Ripard wrote:
> > On Mon, May 26, 2025 at 11:13:01PM +0200, Michael wrote:
> > > On Mon, May 26, 2025 at 07:30:35PM +0200, Maxime Ripard wrote:
> > > > On Mon, May 12, 2025 at 10:27:06PM +0200, Michael wrote:
> > > > > with v6.9 and later there is no output on the BananaPI HDMI connector.
> > > > >
> > > > > I have bisected the issue to the following commit:
> > > > >
> > > > >   358e76fd613a ("drm/sun4i: hdmi: Consolidate atomic_check and mode_valid")
> > > > >
> > > > > With this patch, sun4i_hdmi_connector_clock_valid() is occasionally called
> > > > > with clock=0, causing the function to return MODE_NOCLOCK.
> > > > > In the old sun4i_hdmi_mode_valid() before the patch, mode->clock is
> > > > > always!=0, maybe that gives someone a hint.
> > > >
> > > > This doesn't make sense to me, if only because the two callers of
> > > > tmds_char_rate_valid (hdmi_compute_clock and
> > > > drm_hdmi_connector_mode_valid) have, right before calling it, checks to
> > > > make sure the clock rate isn't 0, and would return MODE_ERROR or EINVAL
> > > > in such a case.
> > > >
> > > > https://elixir.bootlin.com/linux/v6.15/source/drivers/gpu/drm/display/drm_hdmi_state_helper.c#L234
> > > > https://elixir.bootlin.com/linux/v6.15/source/drivers/gpu/drm/display/drm_hdmi_state_helper.c#L553
> > >
> > > Before 6.14, sun4i_hdmi_connector_clock_valid() was also called from
> > > sun4i_hdmi_connector_atomic_check()...
> > >
> > > > Do you have some logs (with dri.devel=0xff)? Does it happen with 6.15 as
> > > > well?
> > >
> > > It does not happen with 6.15, as it was fixed in 6.14 with 84e541b1e58e
> > > ("drm/sun4i: use drm_atomic_helper_connector_hdmi_check()").
> >
> > Then we might still need to backport that patch.
> >
> > Does applying it to 6.9 alone makes it work, or do you need some additional ones (I'm thinking of
> > ae048fc4f96d in particular, which in turn would require 47368ab437fd)
>
> No way to apply this to anything 6.9. The closest I can get it into is 
> 6.11, which requires both ae048fc4f96d and 47368ab437fd (with one 
> trivial conflict) to make it work. Anthing earlier lacks the entire 
> HDMI connector framework.

HDMI signal is fine, but panics when shutting down:

[   80.182719] 8<--- cut here ---
[   80.190019] Unable to handle kernel NULL pointer dereference at virtual address 00000000 when read
[   80.203132] [00000000] *pgd=00000000
[   80.210869] Internal error: Oops: 5 [#1] SMP THUMB2
[   80.219762] Modules linked in: rfkill sunrpc sun4i_gpadc_iio axp20x_adc sunxi_cir sun4i_ts sunxi_cedrus(C) v4l2_mem2mem videobuf2_dma_contig videobuf2_memops videobuf2_v4l2 videodev videobuf2_common mc cpufreq_dt lz4hc evdev lz4 uio_pdrv_genirq uio zram zsmalloc binfmt_misc ledtrig_netdev dm_mod configfs autofs4 ext4 mbcache jbd2 axp20x_usb_power industrialio pinctrl_axp209 lima gpu_sched sun4i_gpadc sunxi phy_generic simpledrm drm_shmem_helper display_connector realtek
[   80.278276] CPU: 0 UID: 0 PID: 1 Comm: systemd-shutdow Tainted: G         C         6.11.11-edge-sunxi #2
[   80.292150] Tainted: [C]=CRAP
[   80.299353] Hardware name: Allwinner sun7i (A20) Family
[   80.308856] PC is at drm_match_cea_mode+0x1a/0x164
[   80.317864] LR is at drm_default_rgb_quant_range+0xd/0x18
[   80.327409] pc : [<c068be8a>]    lr : [<c068bfe1>]    psr: 80000033
[   80.337879] sp : f0819be0  ip : 00000000  fp : c1d99400
[   80.347275] r10: 00000000  r9 : c350e600  r8 : c350f400
[   80.356623] r7 : 00000000  r6 : 00000043  r5 : c1de9840  r4 : c2f72200
[   80.367251] r3 : c1a7b200  r2 : 00000000  r1 : 00000014  r0 : 00000000
[   80.377866] Flags: Nzcv  IRQs on  FIQs on  Mode SVC_32  ISA Thumb  Segment none
[   80.389216] Control: 50c5387d  Table: 4350406a  DAC: 00000051
[   80.398974] Register r0 information: NULL pointer
[   80.407594] Register r1 information: non-paged memory
[   80.416432] Register r2 information: NULL pointer
[   80.424851] Register r3 information: slab task_struct start c1a7b200 pointer offset 0 size 2560
[   80.437302] Register r4 information: slab kmalloc-512 start c2f72200 pointer offset 0 size 512
[   80.449595] Register r5 information: slab kmalloc-2k start c1de9800 pointer offset 64 size 2048
[   80.461962] Register r6 information: non-paged memory
[   80.470615] Register r7 information: NULL pointer
[   80.478819] Register r8 information: slab kmalloc-512 start c350f400 pointer offset 0 size 512
[   80.491012] Register r9 information: slab kmalloc-512 start c350e600 pointer offset 0 size 512
[   80.503137] Register r10 information: NULL pointer
[   80.511370] Register r11 information: slab kmalloc-1k start c1d99400 pointer offset 0 size 1024
[   80.523615] Register r12 information: NULL pointer
[   80.531889] Process systemd-shutdow (pid: 1, stack limit = 0x606ed489)
[   80.541956] Stack: (0xf0819be0 to 0xf081a000)
[   80.549838] 9be0: 00000000 7465f854 00000004 eff95f00 c1a7b480 00153997 00000012 00000000
[   80.561631] 9c00: c16177c8 c16177c8 00000001 c15a0500 eff8b500 2e9eb000 00000014 c01631a9
[   80.573432] 9c20: 00000012 00000000 f0819c38 eff95f00 00000000 c01531f3 00000000 c014fefb
[   80.585202] 9c40: 00000000 ab217527 00000012 00000001 c16177c8 7465f854 00000000 c2f72200
[   80.596929] 9c60: c1de9840 00000043 00000000 c350f400 c350e600 00000000 c1d99400 c068bfe1
[   80.608686] 9c80: 00000000 c06c41e3 00000014 c06aa6b9 c1a7b200 2e9eb000 c160b100 c160b100
[   80.620365] 9ca0: 2e9eb000 2e9eb000 f0819cd0 c350f400 c38c3ec0 c06aab2f c1a7b200 c38c3ec0
[   80.631960] 9cc0: c1de9840 00000043 c2f72200 c350f400 c350e600 00000000 c1d99400 c06aa89f
[   80.643459] 9ce0: 00000043 c29e4740 c15aaec0 00000000 c1a7b200 aa4033e7 00000001 00000000
[   80.654883] 9d00: c0baeee4 c01a248d c1d99400 c0dbfbf0 c0dbfd3c 00000001 c0dbfcc4 00000000
[   80.666249] 9d20: 00000002 c1d99400 c38c3ec0 00000001 c2f72200 00000000 c350e600 c1d99400
[   80.677586] 9d40: c38c3ec0 c06c4c45 c06c4c35 00000014 c1de9840 c067ffc5 c38c3ec0 00000000
[   80.688949] 9d60: 00000000 7465f854 c1de9840 c0698f71 c0698f71 c0dbcfb0 00000000 c069c493
[   80.700343] 9d80: 00000000 7465f854 c3bc60c0 c1d99400 00000000 00000000 00000000 c38c3ec0
[   80.711744] 9da0: c1d99400 00000000 c3bc66c0 00000000 c1c06c54 00000058 4321fedc c0680ca5
[   80.723146] 9dc0: 00000000 7465f854 00000000 c0ab622b 00000000 c1c06c10 00000000 00000000
[   80.734573] 9de0: 00000000 c0ab622b 00000000 c1c06c10 00000000 00000000 00000000 7465f854
[   80.746010] 9e00: c1c466f0 c38c3ec0 00000008 c06ad727 c1d99400 00000000 c1c06c10 c17f01ac
[   80.757468] 9e20: c17a0018 c06ad78d c1a7b200 00000017 0000000b 00000000 00000000 00000000
[   80.768964] 9e40: c1dea868 c1d99504 00000000 7465f854 c1c06c14 c1c06c14 c172b6d0 c06d80cf
[   80.780459] 9e60: c1a7b200 c17a0f4c 00000000 c161357c fee1dead 00000000 c1a7b200 c013e66f
[   80.791939] 9e80: c1a7b200 c013e7fd 00000000 00000000 00000000 00000000 00000000 00000000
[   80.803406] 9ea0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[   80.814873] 9ec0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[   80.826316] 9ee0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[   80.837678] 9f00: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[   80.849011] 9f20: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[   80.860286] 9f40: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[   80.871477] 9f60: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[   80.882646] 9f80: 00000000 00000000 00000000 7465f854 00000000 00000000 00000003 00000058
[   80.893755] 9fa0: c01002a0 c0100061 00000000 00000000 fee1dead 28121969 4321fedc 00000000
[   80.904935] 9fc0: 00000000 00000000 00000003 00000058 bef22d44 00000000 bef22a9c 4321fedc
[   80.916090] 9fe0: 00000058 bef229ec b6c70c55 b6be0656 60000030 fee1dead 00000000 00000000
[   80.927251] Call trace: 
[   80.927270]  drm_match_cea_mode from drm_default_rgb_quant_range+0xd/0x18
[   80.942505]  drm_default_rgb_quant_range from drm_atomic_helper_connector_hdmi_check+0x67/0x520
[   80.954267]  drm_atomic_helper_connector_hdmi_check from drm_atomic_helper_check_modeset+0x363/0x974
[   80.966483]  drm_atomic_helper_check_modeset from sun4i_de_atomic_check+0x11/0x2c
[   80.977035]  sun4i_de_atomic_check from drm_atomic_check_only+0x471/0x730
[   80.986897]  drm_atomic_check_only from drm_atomic_commit+0x61/0xac
[   80.996205]  drm_atomic_commit from drm_atomic_helper_disable_all+0x127/0x130
[   81.006385]  drm_atomic_helper_disable_all from drm_atomic_helper_shutdown+0x5d/0xd0
[   81.017192]  drm_atomic_helper_shutdown from device_shutdown+0xcf/0x174
[   81.026851]  device_shutdown from kernel_power_off+0x2f/0x60
[   81.035541]  kernel_power_off from __do_sys_reboot+0x15d/0x18c
[   81.044367]  __do_sys_reboot from ret_fast_syscall+0x1/0x5c
[   81.052908] Exception stack(0xf0819fa8 to 0xf0819ff0)
[   81.060899] 9fa0:                   00000000 00000000 fee1dead 28121969 4321fedc 00000000
[   81.072085] 9fc0: 00000000 00000000 00000003 00000058 bef22d44 00000000 bef22a9c 4321fedc
[   81.083257] 9fe0: 00000058 bef229ec b6c70c55 b6be0656
[   81.091295] Code: 25a8 921d f04f 0200 (6803) 4605 
[   81.099305] ---[ end trace 0000000000000000 ]---
[   81.107011] Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b
[   81.117724] ---[ end Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b ]---

--
Michael