[Intel-gfx] [PATCH v5] drm/i915: Fix assert_plane() warning on bootup with external display
Shaikh, Azhar
azhar.shaikh at intel.com
Fri Jun 29 17:45:06 UTC 2018
>-----Original Message-----
>From: Ville Syrjälä [mailto:ville.syrjala at linux.intel.com]
>Sent: Friday, June 29, 2018 5:07 AM
>To: Shaikh, Azhar <azhar.shaikh at intel.com>
>Cc: intel-gfx at lists.freedesktop.org; Navare, Manasi D
><manasi.d.navare at intel.com>
>Subject: Re: [PATCH v5] drm/i915: Fix assert_plane() warning on bootup with
>external display
>
>On Wed, Jun 27, 2018 at 05:11:05PM -0700, Azhar Shaikh wrote:
>> On KBL, WHL RVPs, booting up with an external display connected,
>> triggers below warning, when the BiOS brings up the external display too.
>> This warning is not seen during hotplug.
>>
>> [ 3.615226] ------------[ cut here ]------------
>> [ 3.619829] plane 1A assertion failure (expected on, current off)
>> [ 3.632039] WARNING: CPU: 2 PID: 354 at
>drivers/gpu/drm/i915/intel_display.c:1294 assert_plane+0x71/0xbb
>> [ 3.633920] iwlwifi 0000:00:14.3: loaded firmware version 38.c0e03d94.0
>op_mode iwlmvm
>> [ 3.647157] Modules linked in: iwlwifi cfg80211 btusb btrtl btbcm btintel
>bluetooth ecdh_generic
>> [ 3.647163] CPU: 2 PID: 354 Comm: frecon Not tainted 4.17.0-rc7-50176-
>g655af12d39c2 #3
>> [ 3.647165] Hardware name: Intel Corporation CoffeeLake Client
>Platform/WhiskeyLake U DDR4 ERB, BIOS
>CNLSFWR1.R00.X140.B00.1804040304 04/04/2018
>> [ 3.684509] RIP: 0010:assert_plane+0x71/0xbb
>> [ 3.764451] Call Trace:
>> [ 3.766888] intel_atomic_commit_tail+0xa97/0xb77
>> [ 3.771569] intel_atomic_commit+0x26a/0x279
>> [ 3.771572] drm_atomic_helper_set_config+0x5c/0x76
>> [ 3.780670] __drm_mode_set_config_internal+0x66/0x109
>> [ 3.780672] drm_mode_setcrtc+0x4c9/0x5cc
>> [ 3.780674] ? drm_mode_getcrtc+0x162/0x162
>> [ 3.789774] ? drm_mode_getcrtc+0x162/0x162
>> [ 3.798108] drm_ioctl_kernel+0x8d/0xe4
>> [ 3.801926] drm_ioctl+0x27d/0x368
>> [ 3.805311] ? drm_mode_getcrtc+0x162/0x162
>> [ 3.805314] ? selinux_file_ioctl+0x14e/0x199
>> [ 3.805317] vfs_ioctl+0x21/0x2f
>> [ 3.813812] do_vfs_ioctl+0x491/0x4b4
>> [ 3.813813] ? security_file_ioctl+0x37/0x4b
>> [ 3.813816] ksys_ioctl+0x55/0x75
>> [ 3.820672] __x64_sys_ioctl+0x1a/0x1e
>> [ 3.820674] do_syscall_64+0x51/0x5f
>> [ 3.820678] entry_SYSCALL_64_after_hwframe+0x44/0xa9
>> [ 3.828221] RIP: 0033:0x7b5e04953967
>> [ 3.835504] RSP: 002b:00007fff2eafb6f8 EFLAGS: 00000246 ORIG_RAX:
>0000000000000010
>> [ 3.835505] RAX: ffffffffffffffda RBX: 0000000000000002 RCX:
>00007b5e04953967
>> [ 3.835505] RDX: 00007fff2eafb730 RSI: 00000000c06864a2 RDI:
>000000000000000f
>> [ 3.835506] RBP: 00007fff2eafb720 R08: 0000000000000000 R09:
>0000000000000000
>> [ 3.835507] R10: 0000000000000070 R11: 0000000000000246 R12:
>000000000000000f
>> [ 3.879988] R13: 000056bc9dd7d210 R14: 00007fff2eafb730 R15:
>00000000c06864a2
>> [ 3.887081] Code: 48 c7 c7 06 71 a5 be 84 c0 48 c7 c2 06 fd a3 be 48 89 f9 48 0f
>44 ca 84 db 48 0f 45 d7 48 c7 c7 df d3 a4 be 31 c0 e8 af a0 c0 ff <0f> 0b eb 2b 48
>c7 c7 06 fd a3 be 84 c0 48 c7 c2 06 71 a5 be 48
>> [ 3.905845] WARNING: CPU: 2 PID: 354 at
>drivers/gpu/drm/i915/intel_display.c:1294 assert_plane+0x71/0xbb
>> [ 3.920964] ---[ end trace dac692f4ac46391a ]---
>>
>> The warning is seen when mode_setcrtc() is called for pipeB during
>> bootup and before we get a mode_setcrtc() for pipeA, while doing
>> update_crtcs() in intel_atomic_commit_tail().
>> Now since, plane1A is still active after commit, update_crtcs() is
>> done for pipeA and eventually update_plane() for plane1A.
>>
>> intel_plane_state->ctl for plane1A is not updated since set_modecrtc()
>> is called for pipeB. So intel_plane_state->ctl for plane 1A will be 0x0.
>> So doing an update_plane() for plane1A, will result in clearing
>> PLANE_CTL_ENABLE bit, and hence the warning.
>>
>> To fix this warning, force all active planes to recompute their states
>> in probe.
>>
>> Changes in v5:
>> - Drop drm_modeset_lock_all_ctx() since locks will be taken later.
>>
>> Changes in v4:
>> - Handle locking in intel_initial_commit()
>> - Move the for loop inside intel_initial_commit() so that
>> drm_atomic_commit() is called only once
>> - Call intel_initial_commit() only for more than one active crtc on boot.
>> - Save the return value of intel_initial_commit() and print a message in
>> case of an error
>>
>> Changes in v3:
>> - Add comments
>>
>> Changes in v2:
>> - Force all planes to recompute their states.(Ville Syrjälä)
>> - Update the commit message
>>
>> Signed-off-by: Azhar Shaikh <azhar.shaikh at intel.com>
>> Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
>> Cc: Radhakrishna Sripada <radhakrishna.sripada at intel.com>
>> ---
>> drivers/gpu/drm/i915/intel_display.c | 71
>> +++++++++++++++++++++++++++++++++++-
>> 1 file changed, 69 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/intel_display.c
>> b/drivers/gpu/drm/i915/intel_display.c
>> index 3709fa1b6318..866ebbac30e9 100644
>> --- a/drivers/gpu/drm/i915/intel_display.c
>> +++ b/drivers/gpu/drm/i915/intel_display.c
>> @@ -15092,12 +15092,66 @@ static void intel_update_fdi_pll_freq(struct
>drm_i915_private *dev_priv)
>> DRM_DEBUG_DRIVER("FDI PLL freq=%d\n", dev_priv->fdi_pll_freq);
>}
>>
>> +static int intel_initial_commit(struct drm_device *dev) {
>> + struct drm_atomic_state *state = NULL;
>> + struct drm_modeset_acquire_ctx ctx;
>> + struct drm_crtc_state *crtc_state;
>> + struct intel_crtc *intel_crtc;
>
>Just 'crtc'
>
>> + int ret = 0;
>> +
>> + state = drm_atomic_state_alloc(dev);
>> + if (!state)
>> + return -ENOMEM;
>> +
>> + drm_modeset_acquire_init(&ctx, 0);
>> +
>> +retry:
>> + state->acquire_ctx = &ctx;
>> +
>> + for_each_intel_crtc(dev, intel_crtc) {
>> + struct drm_crtc *crtc = &intel_crtc->base;
>
>Please don't add aliasing pointers for the same thing. It's much easier to figure
>out what's what when you don't have N names for the same thing essentially.
>I've been trying to slowly elimninate this kind of mess all over.
>
>Since you don't have any use for intel_ types in this function I'd just go with
>drm_for_each_crtc() here.
Ok, will use that and get rid of all intel_types.
>
>> +
>> + crtc_state = drm_atomic_get_crtc_state(state, crtc);
>> + if (IS_ERR(crtc_state)) {
>> + ret = PTR_ERR(crtc_state);
>> + goto out;
>> + }
>> +
>> + if (crtc_state->active) {
>> + ret = drm_atomic_add_affected_planes(state, crtc);
>> + if (ret)
>> + goto out;
>> + }
>> + }
>> +
>> + ret = drm_atomic_commit(state);
>> + if (ret == -EDEADLK) {
>> + drm_atomic_state_clear(state);
>> + drm_modeset_backoff(&ctx);
>> + goto retry;
>> + }
>> +
>> +out:
>
>The label should be before the EDEADLK handling.
Oh yes! Just checked get_crtc_state() or add_affected_planes() can return EDEADLK.
Will move it before the EDEADLK handling.
>
>> + if (state) {
>
>'state' will never be NULL.
>
>> + drm_atomic_state_put(state);
>> + state = NULL;
>
>Pointless assignment.
Ok, will call only drm_atomic_state_put() unconditionally.
>
>> + }
>> +
>> + drm_modeset_drop_locks(&ctx);
>> + drm_modeset_acquire_fini(&ctx);
>> +
>> + return ret;
>> +}
>> +
>> int intel_modeset_init(struct drm_device *dev) {
>> struct drm_i915_private *dev_priv = to_i915(dev);
>> struct i915_ggtt *ggtt = &dev_priv->ggtt;
>> enum pipe pipe;
>> struct intel_crtc *crtc;
>> + u16 num_active_crtcs;
>> + int ret;
>>
>> dev_priv->modeset_wq =
>alloc_ordered_workqueue("i915_modeset", 0);
>>
>> @@ -15172,8 +15226,6 @@ int intel_modeset_init(struct drm_device *dev)
>> INTEL_INFO(dev_priv)->num_pipes > 1 ? "s" : "");
>>
>> for_each_pipe(dev_priv, pipe) {
>> - int ret;
>> -
>> ret = intel_crtc_init(dev_priv, pipe);
>> if (ret) {
>> drm_mode_config_cleanup(dev);
>> @@ -15203,6 +15255,8 @@ int intel_modeset_init(struct drm_device *dev)
>>
>> if (!crtc->active)
>> continue;
>> + else
>> + num_active_crtcs++;
>
>This seems like needless complexity. There's no harm in doing this thing
>unconditionally.
>
This was to avoid increase in boot time by 20-30msecs when there is only one crtc active during probe.
>>
>> /*
>> * Note that reserving the BIOS fb up front prevents us @@ -
>15222,6
>> +15276,19 @@ int intel_modeset_init(struct drm_device *dev)
>> }
>>
>> /*
>> + * Only in case of more than one active crtc in probe, force
>> + * all active planes to recompute their states. So that on
>> + * mode_setcrtc after probe, all the intel_plane_state variables
>> + * are already calculated and there is no assert_plane warnings
>> + * during bootup.
>> + */
>> + if (num_active_crtcs > 1) {
>> + ret = intel_initial_commit(dev);
>> + if (ret)
>> + DRM_DEBUG_KMS("Initial commit in probe
>failed.\n");
>> + }
>> +
>> + /*
>> * Make sure hardware watermarks really match the state we read
>out.
>> * Note that we need to do this after reconstructing the BIOS fb's
>> * since the watermark calculation done here will use pstate->fb.
>> --
>> 1.9.1
>
>--
>Ville Syrjälä
>Intel
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