Fixed with this patch: http://lists.freedesktop.org/archives/dri-devel/2011-November/016498.html

Alex

-----Original Message----- From: Sergey V. [mailto:sftp.mtuci@gmail.com] Sent: Tuesday, November 15, 2011 2:05 PM To: David Airlie Cc: Deucher, Alexander; dri-devel@lists.freedesktop.org; linux- kernel@vger.kernel.org Subject: radeon/kms: black screen when loading radeon with modeset=1

Kernel from Linus tree, HEAD at 7f80850d3f9fd8fda23a317044aef3a6bafab06b

Loading radeon module with modeset=1 causes black screen.

Usually it happens at boot time, but if run kernel with radeon.modeset=0 then `rmmod radeon; modprobe radeon modeset=1` I can get dmesg over ssh (thanks to glisse from #radeon for help).

Backtrace below:

[ 89.905890] BUG: unable to handle kernel NULL pointer dereference at 0000000000000008 [ 89.906016] IP: [<ffffffffa05998ed>] radeon_atombios_parse_power_table_1_3+0x13d/0x810 [radeon] [ 89.906016] PGD 6a0e1067 PUD 6a09d067 PMD 0 [ 89.906016] Oops: 0002 [#1] SMP [ 89.906016] CPU 0 [ 89.906016] Modules linked in: radeon(+) snd_seq_dummy snd_seq_oss snd_seq_midi_event snd_seq snd_seq_device snd_pcm_oss snd_mixer_oss ipv6 btrfs cpufreq_ondemand powernow_k8 freq_table mperf lp ppdev parport_pc parport fuse snd_hda_codec_hdmi snd_hda_codec_realtek processor ttm drm_kms_helper drm thermal i2c_piix4 joydev agpgart video snd_hda_intel r8169 thermal_sys i2c_algo_bit i2c_core k8temp battery sdhci_pci snd_hda_codec evdev hwmon mii button ac shpchp sdhci snd_hwdep snd_pcm psmouse serio_raw mmc_core snd_timer sg snd soundcore snd_page_alloc [last unloaded: radeon] [ 89.906016] [ 89.906016] Pid: 2189, comm: modprobe Tainted: G W 3.2.0-rc1+ #4 Micro-Star International PR210/MS-1222 [ 89.906016] RIP: 0010:[<ffffffffa05998ed>] [<ffffffffa05998ed>] radeon_atombios_parse_power_table_1_3+0x13d/0x810 [radeon] [ 89.906016] RSP: 0018:ffff880075959948 EFLAGS: 00010246 [ 89.906016] RAX: 0000000000000000 RBX: ffff880075b72000 RCX: 0000000000000000 [ 89.906016] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff880076c73c00 [ 89.906016] RBP: ffff880075959a98 R08: 0000000000000000 R09: ffff880076c73a00 [ 89.906016] R10: ffff8800758a0000 R11: 0000000000000006 R12: ffff8800758aadde [ 89.906016] R13: ffff8800758aadde R14: 0000000000000000 R15: 0000000000000000 [ 89.906016] FS: 00007f57d0b27720(0000) GS:ffff88007bc00000(0000) knlGS:00000000f702a6d0 [ 89.906016] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [ 89.906016] CR2: 0000000000000008 CR3: 000000006a0a6000 CR4: 00000000000006f0 [ 89.906016] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 89.906016] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 [ 89.906016] Process modprobe (pid: 2189, threadinfo ffff880075958000, task ffff880075abc6d0) [ 89.906016] Stack: [ 89.906016] ffff88000000ffff ffff8800768f400a ffff880000000000 00ffffff00000000 [ 89.906016] ffff880037653663 ffff880075b73158 ffff880075b73174 0000000675959acf [ 89.906016] ffffffff81b6112c ffff880075959a38 ffffffff81b6112e ffff880075959ad5 [ 89.906016] Call Trace: [ 89.906016] [<ffffffff81289dce>] ? vsnprintf+0x31e/0x5d0 [ 89.906016] [<ffffffff81289dce>] ? vsnprintf+0x31e/0x5d0 [ 89.906016] [<ffffffff81076511>] ? up+0x31/0x50 [ 89.906016] [<ffffffff81050494>] ? console_unlock+0x1c4/0x230 [ 89.906016] [<ffffffffa059cb98>] radeon_atombios_get_power_modes+0x228/0x8e0 [radeon] [ 89.906016] [<ffffffffa05e7e01>] radeon_pm_init+0x3b1/0x590 [radeon] [ 89.906016] [<ffffffffa05d0039>] ? rs600_irq_set+0x109/0x180 [radeon] [ 89.906016] [<ffffffffa05b7ca9>] radeon_modeset_init+0x4c9/0x8a0 [radeon] [ 89.906016] [<ffffffffa05fb3dc>] ? radeon_acpi_init+0x8c/0xbc [radeon] [ 89.906016] [<ffffffffa0598760>] radeon_driver_load_kms+0x120/0x170 [radeon] [ 89.906016] [<ffffffffa024d82e>] drm_get_pci_dev+0x18e/0x2c0 [drm] [ 89.906016] [<ffffffffa05fb4b9>] radeon_pci_probe+0xad/0xb5 [radeon] [ 89.906016] [<ffffffff812a8edf>] local_pci_probe+0x5f/0xd0 [ 89.906016] [<ffffffff812a97b8>] pci_device_probe+0x88/0xb0 [ 89.906016] [<ffffffff81331bca>] ? driver_sysfs_add+0x7a/0xb0 [ 89.906016] [<ffffffff81331ed6>] driver_probe_device+0x96/0x1b0 [ 89.906016] [<ffffffff81332093>] __driver_attach+0xa3/0xb0 [ 89.906016] [<ffffffff81331ff0>] ? driver_probe_device+0x1b0/0x1b0 [ 89.906016] [<ffffffff81330e9e>] bus_for_each_dev+0x5e/0x90 [ 89.906016] [<ffffffff81331b4e>] driver_attach+0x1e/0x20 [ 89.906016] [<ffffffff81331745>] bus_add_driver+0x155/0x280 [ 89.906016] [<ffffffff81332676>] driver_register+0x76/0x140 [ 89.906016] [<ffffffff812a9a45>] __pci_register_driver+0x55/0xd0 [ 89.906016] [<ffffffffa024da71>] drm_pci_init+0x111/0x120 [drm] [ 89.906016] [<ffffffffa0639000>] ? 0xffffffffa0638fff [ 89.906016] [<ffffffffa0639000>] ? 0xffffffffa0638fff [ 89.906016] [<ffffffffa06390ec>] radeon_init+0xec/0xee [radeon] [ 89.906016] [<ffffffff810002d4>] do_one_initcall+0x44/0x170 [ 89.906016] [<ffffffff8108c332>] sys_init_module+0x92/0x1e0 [ 89.906016] [<ffffffff817fba6b>] system_call_fastpath+0x16/0x1b [ 89.906016] Code: 16 44 3b b5 ec fe ff ff 0f 8d 40 01 00 00 48 8b 83 58 11 00 00 49 63 cf 48 89 ca 48 c1 e1 06 48 c1 e2 04 48 29 d1 48 8b 44 08 08 <c7> 40 08 00 00 00 00 0f b6 45 8f 3c 02 75 ac 4c 8b 83 58 11 00 [ 89.906016] RIP [<ffffffffa05998ed>] radeon_atombios_parse_power_table_1_3+0x13d/0x810 [radeon] [ 89.906016] RSP <ffff880075959948> [ 89.906016] CR2: 0000000000000008 [ 89.918682] ---[ end trace 758728fd12807b58 ]---

Whole dmesg output attached.