We need to grab the lock after the early return for !hwpipe case.
Otherwise, we could have hit contention yet still returned 0.
Fixes an issue that the new CONFIG_DRM_DEBUG_MODESET_LOCK stuff flagged
in CI:
WARNING: CPU: 0 PID: 282 at drivers/gpu/drm/drm_modeset_lock.c:296 drm_modeset_lock+0xf8/0x154
Modules linked in:
CPU: 0 PID: 282 Comm: kms_cursor_lega Tainted: G W 5.19.0-rc2-15930-g875cc8bc536a #1
Hardware name: Qualcomm Technologies, Inc. DB820c (DT)
pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : drm_modeset_lock+0xf8/0x154
lr : drm_atomic_get_private_obj_state+0x84/0x170
sp : ffff80000cfab6a0
x29: ffff80000cfab6a0 x28: 0000000000000000 x27: ffff000083bc4d00
x26: 0000000000000038 x25: 0000000000000000 x24: ffff80000957ca58
x23: 0000000000000000 x22: ffff000081ace080 x21: 0000000000000001
x20: ffff000081acec18 x19: ffff80000cfabb80 x18: 0000000000000038
x17: 0000000000000000 x16: 0000000000000000 x15: fffffffffffea0d0
x14: 0000000000000000 x13: 284e4f5f4e524157 x12: 5f534b434f4c5f47
x11: ffff80000a386aa8 x10: 0000000000000029 x9 : ffff80000cfab610
x8 : 0000000000000029 x7 : 0000000000000014 x6 : 0000000000000000
x5 : 0000000000000001 x4 : ffff8000081ad904 x3 : 0000000000000029
x2 : ffff0000801db4c0 x1 : ffff80000cfabb80 x0 : ffff000081aceb58
Call trace:
drm_modeset_lock+0xf8/0x154
drm_atomic_get_private_obj_state+0x84/0x170
mdp5_get_global_state+0x54/0x6c
mdp5_pipe_release+0x2c/0xd4
mdp5_plane_atomic_check+0x2ec/0x414
drm_atomic_helper_check_planes+0xd8/0x210
drm_atomic_helper_check+0x54/0xb0
...
---[ end trace 0000000000000000 ]---
drm_modeset_lock attempting to lock a contended lock without backoff:
drm_modeset_lock+0x148/0x154
mdp5_get_global_state+0x30/0x6c
mdp5_pipe_release+0x2c/0xd4
mdp5_plane_atomic_check+0x290/0x414
drm_atomic_helper_check_planes+0xd8/0x210
drm_atomic_helper_check+0x54/0xb0
drm_atomic_check_only+0x4b0/0x8f4
drm_atomic_commit+0x68/0xe0
Fixes: d59be579fa
("drm/msm/mdp5: Return error code in mdp5_pipe_release when deadlock is detected")
Signed-off-by: Rob Clark <robdclark@chromium.org>
Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
Patchwork: https://patchwork.freedesktop.org/patch/492701/
Link: https://lore.kernel.org/r/20220707162040.1594855-1-robdclark@gmail.com
176 lines
4.3 KiB
C
176 lines
4.3 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Copyright (C) 2016 Red Hat
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* Author: Rob Clark <robdclark@gmail.com>
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*/
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#include "mdp5_kms.h"
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int mdp5_pipe_assign(struct drm_atomic_state *s, struct drm_plane *plane,
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uint32_t caps, uint32_t blkcfg,
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struct mdp5_hw_pipe **hwpipe,
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struct mdp5_hw_pipe **r_hwpipe)
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{
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struct msm_drm_private *priv = s->dev->dev_private;
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struct mdp5_kms *mdp5_kms = to_mdp5_kms(to_mdp_kms(priv->kms));
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struct mdp5_global_state *new_global_state, *old_global_state;
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struct mdp5_hw_pipe_state *old_state, *new_state;
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int i, j;
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new_global_state = mdp5_get_global_state(s);
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if (IS_ERR(new_global_state))
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return PTR_ERR(new_global_state);
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/* grab old_state after mdp5_get_global_state(), since now we hold lock: */
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old_global_state = mdp5_get_existing_global_state(mdp5_kms);
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old_state = &old_global_state->hwpipe;
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new_state = &new_global_state->hwpipe;
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for (i = 0; i < mdp5_kms->num_hwpipes; i++) {
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struct mdp5_hw_pipe *cur = mdp5_kms->hwpipes[i];
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/* skip if already in-use.. check both new and old state,
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* since we cannot immediately re-use a pipe that is
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* released in the current update in some cases:
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* (1) mdp5 can have SMP (non-double-buffered)
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* (2) hw pipe previously assigned to different CRTC
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* (vblanks might not be aligned)
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*/
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if (new_state->hwpipe_to_plane[cur->idx] ||
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old_state->hwpipe_to_plane[cur->idx])
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continue;
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/* skip if doesn't support some required caps: */
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if (caps & ~cur->caps)
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continue;
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/*
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* don't assign a cursor pipe to a plane that isn't going to
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* be used as a cursor
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*/
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if (cur->caps & MDP_PIPE_CAP_CURSOR &&
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plane->type != DRM_PLANE_TYPE_CURSOR)
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continue;
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/* possible candidate, take the one with the
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* fewest unneeded caps bits set:
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*/
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if (!(*hwpipe) || (hweight_long(cur->caps & ~caps) <
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hweight_long((*hwpipe)->caps & ~caps))) {
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bool r_found = false;
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if (r_hwpipe) {
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for (j = i + 1; j < mdp5_kms->num_hwpipes;
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j++) {
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struct mdp5_hw_pipe *r_cur =
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mdp5_kms->hwpipes[j];
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/* reject different types of hwpipes */
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if (r_cur->caps != cur->caps)
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continue;
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/* respect priority, eg. VIG0 > VIG1 */
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if (cur->pipe > r_cur->pipe)
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continue;
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*r_hwpipe = r_cur;
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r_found = true;
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break;
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}
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}
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if (!r_hwpipe || r_found)
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*hwpipe = cur;
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}
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}
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if (!(*hwpipe))
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return -ENOMEM;
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if (r_hwpipe && !(*r_hwpipe))
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return -ENOMEM;
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if (mdp5_kms->smp) {
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int ret;
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/* We don't support SMP and 2 hwpipes/plane together */
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WARN_ON(r_hwpipe);
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DBG("%s: alloc SMP blocks", (*hwpipe)->name);
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ret = mdp5_smp_assign(mdp5_kms->smp, &new_global_state->smp,
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(*hwpipe)->pipe, blkcfg);
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if (ret)
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return -ENOMEM;
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(*hwpipe)->blkcfg = blkcfg;
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}
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DBG("%s: assign to plane %s for caps %x",
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(*hwpipe)->name, plane->name, caps);
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new_state->hwpipe_to_plane[(*hwpipe)->idx] = plane;
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if (r_hwpipe) {
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DBG("%s: assign to right of plane %s for caps %x",
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(*r_hwpipe)->name, plane->name, caps);
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new_state->hwpipe_to_plane[(*r_hwpipe)->idx] = plane;
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}
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return 0;
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}
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int mdp5_pipe_release(struct drm_atomic_state *s, struct mdp5_hw_pipe *hwpipe)
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{
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struct msm_drm_private *priv = s->dev->dev_private;
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struct mdp5_kms *mdp5_kms = to_mdp5_kms(to_mdp_kms(priv->kms));
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struct mdp5_global_state *state;
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struct mdp5_hw_pipe_state *new_state;
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if (!hwpipe)
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return 0;
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state = mdp5_get_global_state(s);
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if (IS_ERR(state))
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return PTR_ERR(state);
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new_state = &state->hwpipe;
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if (WARN_ON(!new_state->hwpipe_to_plane[hwpipe->idx]))
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return -EINVAL;
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DBG("%s: release from plane %s", hwpipe->name,
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new_state->hwpipe_to_plane[hwpipe->idx]->name);
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if (mdp5_kms->smp) {
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DBG("%s: free SMP blocks", hwpipe->name);
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mdp5_smp_release(mdp5_kms->smp, &state->smp, hwpipe->pipe);
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}
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new_state->hwpipe_to_plane[hwpipe->idx] = NULL;
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return 0;
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}
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void mdp5_pipe_destroy(struct mdp5_hw_pipe *hwpipe)
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{
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kfree(hwpipe);
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}
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struct mdp5_hw_pipe *mdp5_pipe_init(enum mdp5_pipe pipe,
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uint32_t reg_offset, uint32_t caps)
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{
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struct mdp5_hw_pipe *hwpipe;
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hwpipe = kzalloc(sizeof(*hwpipe), GFP_KERNEL);
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if (!hwpipe)
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return ERR_PTR(-ENOMEM);
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hwpipe->name = pipe2name(pipe);
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hwpipe->pipe = pipe;
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hwpipe->reg_offset = reg_offset;
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hwpipe->caps = caps;
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hwpipe->flush_mask = mdp_ctl_flush_mask_pipe(pipe);
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return hwpipe;
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}
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