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authorJani Nikula <jani.nikula@intel.com>2018-04-11 09:15:18 -0400
committerJoonas Lahtinen <joonas.lahtinen@linux.intel.com>2018-04-18 07:17:13 -0400
commita3520b8992e57bc94ab6ec9f95f09c6c932555fd (patch)
tree7cb69da4d09560a06c53be4a7bdd34f3f607ed6e
parente6be6bd85654dba55b97758f937c46835d961a44 (diff)
drm/i915/bios: filter out invalid DDC pins from VBT child devices
The VBT contains the DDC pin to use for specific ports. Alas, sometimes the field appears to contain bogus data, and while we check for it later on in intel_gmbus_get_adapter() we fail to check the returned NULL on errors. Oops results. The simplest approach seems to be to catch and ignore the bogus DDC pins already at the VBT parsing phase, reverting to fixed per port default pins. This doesn't guarantee display working, but at least it prevents the oops. And we continue to be fuzzed by VBT. One affected machine is Dell Latitude 5590 where a BIOS upgrade added invalid DDC pins. Typical backtrace: [ 35.461411] WARN_ON(!intel_gmbus_is_valid_pin(dev_priv, pin)) [ 35.461432] WARNING: CPU: 6 PID: 411 at drivers/gpu/drm/i915/intel_i2c.c:844 intel_gmbus_get_adapter+0x32/0x37 [i915] [ 35.461437] Modules linked in: i915 ahci libahci dm_snapshot dm_bufio dm_raid raid456 async_raid6_recov async_pq raid6_pq async_xor xor async_memcpy async_tx [ 35.461445] CPU: 6 PID: 411 Comm: kworker/u16:2 Not tainted 4.16.0-rc7.x64-g1cda370ffded #1 [ 35.461447] Hardware name: Dell Inc. Latitude 5590/0MM81M, BIOS 1.1.9 03/13/2018 [ 35.461450] Workqueue: events_unbound async_run_entry_fn [ 35.461465] RIP: 0010:intel_gmbus_get_adapter+0x32/0x37 [i915] [ 35.461467] RSP: 0018:ffff9b4e43d47c40 EFLAGS: 00010286 [ 35.461469] RAX: 0000000000000000 RBX: ffff98f90639f800 RCX: ffffffffae051960 [ 35.461471] RDX: 0000000000000001 RSI: 0000000000000092 RDI: 0000000000000246 [ 35.461472] RBP: ffff98f905410000 R08: 0000004d062a83f6 R09: 00000000000003bd [ 35.461474] R10: 0000000000000031 R11: ffffffffad4eda58 R12: ffff98f905410000 [ 35.461475] R13: ffff98f9064c1000 R14: ffff9b4e43d47cf0 R15: ffff98f905410000 [ 35.461477] FS: 0000000000000000(0000) GS:ffff98f92e580000(0000) knlGS:0000000000000000 [ 35.461479] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 35.461481] CR2: 00007f5682359008 CR3: 00000001b700c005 CR4: 00000000003606e0 [ 35.461483] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 35.461484] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 35.461486] Call Trace: [ 35.461501] intel_hdmi_set_edid+0x37/0x27f [i915] [ 35.461515] intel_hdmi_detect+0x7c/0x97 [i915] [ 35.461518] drm_helper_probe_single_connector_modes+0xe1/0x6c0 [ 35.461521] drm_setup_crtcs+0x129/0xa6a [ 35.461523] ? __switch_to_asm+0x34/0x70 [ 35.461525] ? __switch_to_asm+0x34/0x70 [ 35.461527] ? __switch_to_asm+0x40/0x70 [ 35.461528] ? __switch_to_asm+0x34/0x70 [ 35.461529] ? __switch_to_asm+0x40/0x70 [ 35.461531] ? __switch_to_asm+0x34/0x70 [ 35.461532] ? __switch_to_asm+0x40/0x70 [ 35.461534] ? __switch_to_asm+0x34/0x70 [ 35.461536] __drm_fb_helper_initial_config_and_unlock+0x34/0x46f [ 35.461538] ? __switch_to_asm+0x40/0x70 [ 35.461541] ? _cond_resched+0x10/0x33 [ 35.461557] intel_fbdev_initial_config+0xf/0x1c [i915] [ 35.461560] async_run_entry_fn+0x2e/0xf5 [ 35.461563] process_one_work+0x15b/0x364 [ 35.461565] worker_thread+0x2c/0x3a0 [ 35.461567] ? process_one_work+0x364/0x364 [ 35.461568] kthread+0x10c/0x122 [ 35.461570] ? _kthread_create_on_node+0x5d/0x5d [ 35.461572] ret_from_fork+0x35/0x40 [ 35.461574] Code: 74 16 89 f6 48 8d 04 b6 48 c1 e0 05 48 29 f0 48 8d 84 c7 e8 11 00 00 c3 48 c7 c6 b0 19 1e c0 48 c7 c7 64 8a 1c c0 e8 47 88 ed ec <0f> 0b 31 c0 c3 8b 87 a4 04 00 00 80 e4 fc 09 c6 89 b7 a4 04 00 [ 35.461604] WARNING: CPU: 6 PID: 411 at drivers/gpu/drm/i915/intel_i2c.c:844 intel_gmbus_get_adapter+0x32/0x37 [i915] [ 35.461606] ---[ end trace 4fe1e63e2dd93373 ]--- [ 35.461609] BUG: unable to handle kernel NULL pointer dereference at 0000000000000010 [ 35.461613] IP: i2c_transfer+0x4/0x86 [ 35.461614] PGD 0 P4D 0 [ 35.461616] Oops: 0000 [#1] SMP PTI [ 35.461618] Modules linked in: i915 ahci libahci dm_snapshot dm_bufio dm_raid raid456 async_raid6_recov async_pq raid6_pq async_xor xor async_memcpy async_tx [ 35.461624] CPU: 6 PID: 411 Comm: kworker/u16:2 Tainted: G W 4.16.0-rc7.x64-g1cda370ffded #1 [ 35.461625] Hardware name: Dell Inc. Latitude 5590/0MM81M, BIOS 1.1.9 03/13/2018 [ 35.461628] Workqueue: events_unbound async_run_entry_fn [ 35.461630] RIP: 0010:i2c_transfer+0x4/0x86 [ 35.461631] RSP: 0018:ffff9b4e43d47b30 EFLAGS: 00010246 [ 35.461633] RAX: ffff9b4e43d47b6e RBX: 0000000000000005 RCX: 0000000000000001 [ 35.461635] RDX: 0000000000000002 RSI: ffff9b4e43d47b80 RDI: 0000000000000000 [ 35.461636] RBP: ffff9b4e43d47bd8 R08: 0000004d062a83f6 R09: 00000000000003bd [ 35.461638] R10: 0000000000000031 R11: ffffffffad4eda58 R12: 0000000000000002 [ 35.461639] R13: 0000000000000001 R14: ffff9b4e43d47b6f R15: ffff9b4e43d47c07 [ 35.461641] FS: 0000000000000000(0000) GS:ffff98f92e580000(0000) knlGS:0000000000000000 [ 35.461643] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 35.461645] CR2: 0000000000000010 CR3: 00000001b700c005 CR4: 00000000003606e0 [ 35.461646] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 35.461647] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 35.461649] Call Trace: [ 35.461652] drm_do_probe_ddc_edid+0xb3/0x128 [ 35.461654] drm_get_edid+0xe5/0x38d [ 35.461669] intel_hdmi_set_edid+0x45/0x27f [i915] [ 35.461684] intel_hdmi_detect+0x7c/0x97 [i915] [ 35.461687] drm_helper_probe_single_connector_modes+0xe1/0x6c0 [ 35.461689] drm_setup_crtcs+0x129/0xa6a [ 35.461691] ? __switch_to_asm+0x34/0x70 [ 35.461693] ? __switch_to_asm+0x34/0x70 [ 35.461694] ? __switch_to_asm+0x40/0x70 [ 35.461696] ? __switch_to_asm+0x34/0x70 [ 35.461697] ? __switch_to_asm+0x40/0x70 [ 35.461698] ? __switch_to_asm+0x34/0x70 [ 35.461700] ? __switch_to_asm+0x40/0x70 [ 35.461701] ? __switch_to_asm+0x34/0x70 [ 35.461703] __drm_fb_helper_initial_config_and_unlock+0x34/0x46f [ 35.461705] ? __switch_to_asm+0x40/0x70 [ 35.461707] ? _cond_resched+0x10/0x33 [ 35.461724] intel_fbdev_initial_config+0xf/0x1c [i915] [ 35.461727] async_run_entry_fn+0x2e/0xf5 [ 35.461729] process_one_work+0x15b/0x364 [ 35.461731] worker_thread+0x2c/0x3a0 [ 35.461733] ? process_one_work+0x364/0x364 [ 35.461734] kthread+0x10c/0x122 [ 35.461736] ? _kthread_create_on_node+0x5d/0x5d [ 35.461738] ret_from_fork+0x35/0x40 [ 35.461739] Code: 5c fa e1 ad 48 89 df e8 ea fb ff ff e9 2a ff ff ff 0f 1f 44 00 00 31 c0 e9 43 fd ff ff 31 c0 45 31 e4 e9 c5 fd ff ff 41 54 55 53 <48> 8b 47 10 48 83 78 10 00 74 70 41 89 d4 48 89 f5 48 89 fb 65 [ 35.461756] RIP: i2c_transfer+0x4/0x86 RSP: ffff9b4e43d47b30 [ 35.461757] CR2: 0000000000000010 [ 35.461759] ---[ end trace 4fe1e63e2dd93374 ]--- Based on a patch by Fei Li. v2: s/reverting/sticking/ (Chris) Cc: stable@vger.kernel.org Cc: Fei Li <fei.li@intel.com> Co-developed-by: Fei Li <fei.li@intel.com> Reported-by: Pavel Nakonechnyi <zorg1331@gmail.com> Reported-and-tested-by: Seweryn Kokot <sewkokot@gmail.com> Reported-and-tested-by: Laszlo Valko <valko@linux.karinthy.hu> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=105549 Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=105961 Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> Signed-off-by: Jani Nikula <jani.nikula@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20180411131519.9091-1-jani.nikula@intel.com (cherry picked from commit f212bf9abe5de9f938fecea7df07046e74052dde) Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Diffstat
-rw-r--r--drivers/gpu/drm/i915/intel_bios.c13
1 files changed, 9 insertions, 4 deletions
diff --git a/drivers/gpu/drm/i915/intel_bios.c b/drivers/gpu/drm/i915/intel_bios.c
index c5c7530ba157..447b721c3be9 100644
--- a/drivers/gpu/drm/i915/intel_bios.c
+++ b/drivers/gpu/drm/i915/intel_bios.c
@@ -1256,7 +1256,6 @@ static void parse_ddi_port(struct drm_i915_private *dev_priv, enum port port,
1256 return; 1256 return;
1257 1257
1258 aux_channel = child->aux_channel; 1258 aux_channel = child->aux_channel;
1259 ddc_pin = child->ddc_pin;
1260 1259
1261 is_dvi = child->device_type & DEVICE_TYPE_TMDS_DVI_SIGNALING; 1260 is_dvi = child->device_type & DEVICE_TYPE_TMDS_DVI_SIGNALING;
1262 is_dp = child->device_type & DEVICE_TYPE_DISPLAYPORT_OUTPUT; 1261 is_dp = child->device_type & DEVICE_TYPE_DISPLAYPORT_OUTPUT;
@@ -1303,9 +1302,15 @@ static void parse_ddi_port(struct drm_i915_private *dev_priv, enum port port,
1303 DRM_DEBUG_KMS("Port %c is internal DP\n", port_name(port)); 1302 DRM_DEBUG_KMS("Port %c is internal DP\n", port_name(port));
1304 1303
1305 if (is_dvi) { 1304 if (is_dvi) {
1306 info->alternate_ddc_pin = map_ddc_pin(dev_priv, ddc_pin); 1305 ddc_pin = map_ddc_pin(dev_priv, child->ddc_pin);
1307 1306 if (intel_gmbus_is_valid_pin(dev_priv, ddc_pin)) {
1308 sanitize_ddc_pin(dev_priv, port); 1307 info->alternate_ddc_pin = ddc_pin;
1308 sanitize_ddc_pin(dev_priv, port);
1309 } else {
1310 DRM_DEBUG_KMS("Port %c has invalid DDC pin %d, "
1311 "sticking to defaults\n",
1312 port_name(port), ddc_pin);
1313 }
1309 } 1314 }
1310 1315
1311 if (is_dp) { 1316 if (is_dp) {
generated by cgit v1.2.2 (git 2.25.0) at 2025-08-19 03:31:29 -0400