linux/drivers/gpu/drm/tidss/tidss_crtc.c
Tomi Valkeinen c079e2e113 drm/tidss: Fix sync-lost issue with two displays
A sync lost issue can be observed with two displays, when moving a plane
from one disabled display to an another disabled display, and then
enabling the display to which the plane was moved to. The exact
requirements for this to trigger are not clear.

It looks like the issue is that the layers are left enabled in the first
display's OVR registers. Even if the corresponding VP is disabled, it
still causes an issue, as if the disabled VP and its OVR would still be
in use, leading to the same VID being used by two OVRs. However, this is
just speculation based on testing the DSS behavior.

Experimentation shows that as a workaround, we can disable all the
layers in the OVR when disabling a VP. There should be no downside to
this, as the OVR is anyway effectively disabled if its VP is disabled,
and it seems to solve the sync lost issue.

However, there may be a bigger issue in play here, related to J721e
erratum i2097 ("DSS: Disabling a Layer Connected to Overlay May Result
in Synclost During the Next Frame"). Experimentation also shows that the
OVR's CHANNELIN field has similar issue. So we may need to revisit this
when we find out more about the core issue.

Fixes: 32a1795f57 ("drm/tidss: New driver for TI Keystone platform Display SubSystem")
Reviewed-by: Aradhya Bhatia <a-bhatia1@ti.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240213-tidss-fixes-v1-2-d709e8dfa505@ideasonboard.com
2024-02-26 10:09:43 +02:00

451 lines
12 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2018 Texas Instruments Incorporated - https://www.ti.com/
* Author: Tomi Valkeinen <tomi.valkeinen@ti.com>
*/
#include <drm/drm_atomic.h>
#include <drm/drm_atomic_helper.h>
#include <drm/drm_crtc.h>
#include <drm/drm_gem_dma_helper.h>
#include <drm/drm_vblank.h>
#include "tidss_crtc.h"
#include "tidss_dispc.h"
#include "tidss_drv.h"
#include "tidss_irq.h"
#include "tidss_plane.h"
/* Page flip and frame done IRQs */
static void tidss_crtc_finish_page_flip(struct tidss_crtc *tcrtc)
{
struct drm_device *ddev = tcrtc->crtc.dev;
struct tidss_device *tidss = to_tidss(ddev);
struct drm_pending_vblank_event *event;
unsigned long flags;
bool busy;
spin_lock_irqsave(&ddev->event_lock, flags);
/*
* New settings are taken into use at VFP, and GO bit is cleared at
* the same time. This happens before the vertical blank interrupt.
* So there is a small change that the driver sets GO bit after VFP, but
* before vblank, and we have to check for that case here.
*/
busy = dispc_vp_go_busy(tidss->dispc, tcrtc->hw_videoport);
if (busy) {
spin_unlock_irqrestore(&ddev->event_lock, flags);
return;
}
event = tcrtc->event;
tcrtc->event = NULL;
if (!event) {
spin_unlock_irqrestore(&ddev->event_lock, flags);
return;
}
drm_crtc_send_vblank_event(&tcrtc->crtc, event);
spin_unlock_irqrestore(&ddev->event_lock, flags);
drm_crtc_vblank_put(&tcrtc->crtc);
}
void tidss_crtc_vblank_irq(struct drm_crtc *crtc)
{
struct tidss_crtc *tcrtc = to_tidss_crtc(crtc);
drm_crtc_handle_vblank(crtc);
tidss_crtc_finish_page_flip(tcrtc);
}
void tidss_crtc_framedone_irq(struct drm_crtc *crtc)
{
struct tidss_crtc *tcrtc = to_tidss_crtc(crtc);
complete(&tcrtc->framedone_completion);
}
void tidss_crtc_error_irq(struct drm_crtc *crtc, u64 irqstatus)
{
struct tidss_crtc *tcrtc = to_tidss_crtc(crtc);
dev_err_ratelimited(crtc->dev->dev, "CRTC%u SYNC LOST: (irq %llx)\n",
tcrtc->hw_videoport, irqstatus);
}
/* drm_crtc_helper_funcs */
static int tidss_crtc_atomic_check(struct drm_crtc *crtc,
struct drm_atomic_state *state)
{
struct drm_crtc_state *crtc_state = drm_atomic_get_new_crtc_state(state,
crtc);
struct drm_device *ddev = crtc->dev;
struct tidss_device *tidss = to_tidss(ddev);
struct dispc_device *dispc = tidss->dispc;
struct tidss_crtc *tcrtc = to_tidss_crtc(crtc);
u32 hw_videoport = tcrtc->hw_videoport;
const struct drm_display_mode *mode;
enum drm_mode_status ok;
dev_dbg(ddev->dev, "%s\n", __func__);
if (!crtc_state->enable)
return 0;
mode = &crtc_state->adjusted_mode;
ok = dispc_vp_mode_valid(dispc, hw_videoport, mode);
if (ok != MODE_OK) {
dev_dbg(ddev->dev, "%s: bad mode: %ux%u pclk %u kHz\n",
__func__, mode->hdisplay, mode->vdisplay, mode->clock);
return -EINVAL;
}
return dispc_vp_bus_check(dispc, hw_videoport, crtc_state);
}
/*
* This needs all affected planes to be present in the atomic
* state. The untouched planes are added to the state in
* tidss_atomic_check().
*/
static void tidss_crtc_position_planes(struct tidss_device *tidss,
struct drm_crtc *crtc,
struct drm_crtc_state *old_state,
bool newmodeset)
{
struct drm_atomic_state *ostate = old_state->state;
struct tidss_crtc *tcrtc = to_tidss_crtc(crtc);
struct drm_crtc_state *cstate = crtc->state;
int layer;
if (!newmodeset && !cstate->zpos_changed &&
!to_tidss_crtc_state(cstate)->plane_pos_changed)
return;
for (layer = 0; layer < tidss->feat->num_planes; layer++) {
struct drm_plane_state *pstate;
struct drm_plane *plane;
bool layer_active = false;
int i;
for_each_new_plane_in_state(ostate, plane, pstate, i) {
if (pstate->crtc != crtc || !pstate->visible)
continue;
if (pstate->normalized_zpos == layer) {
layer_active = true;
break;
}
}
if (layer_active) {
struct tidss_plane *tplane = to_tidss_plane(plane);
dispc_ovr_set_plane(tidss->dispc, tplane->hw_plane_id,
tcrtc->hw_videoport,
pstate->crtc_x, pstate->crtc_y,
layer);
}
dispc_ovr_enable_layer(tidss->dispc, tcrtc->hw_videoport, layer,
layer_active);
}
}
static void tidss_crtc_atomic_flush(struct drm_crtc *crtc,
struct drm_atomic_state *state)
{
struct drm_crtc_state *old_crtc_state = drm_atomic_get_old_crtc_state(state,
crtc);
struct tidss_crtc *tcrtc = to_tidss_crtc(crtc);
struct drm_device *ddev = crtc->dev;
struct tidss_device *tidss = to_tidss(ddev);
unsigned long flags;
dev_dbg(ddev->dev, "%s: %s is %sactive, %s modeset, event %p\n",
__func__, crtc->name, crtc->state->active ? "" : "not ",
drm_atomic_crtc_needs_modeset(crtc->state) ? "needs" : "doesn't need",
crtc->state->event);
/*
* Flush CRTC changes with go bit only if new modeset is not
* coming, so CRTC is enabled trough out the commit.
*/
if (drm_atomic_crtc_needs_modeset(crtc->state))
return;
/* If the GO bit is stuck we better quit here. */
if (WARN_ON(dispc_vp_go_busy(tidss->dispc, tcrtc->hw_videoport)))
return;
/* We should have event if CRTC is enabled through out this commit. */
if (WARN_ON(!crtc->state->event))
return;
/* Write vp properties to HW if needed. */
dispc_vp_setup(tidss->dispc, tcrtc->hw_videoport, crtc->state, false);
/* Update plane positions if needed. */
tidss_crtc_position_planes(tidss, crtc, old_crtc_state, false);
WARN_ON(drm_crtc_vblank_get(crtc) != 0);
spin_lock_irqsave(&ddev->event_lock, flags);
dispc_vp_go(tidss->dispc, tcrtc->hw_videoport);
WARN_ON(tcrtc->event);
tcrtc->event = crtc->state->event;
crtc->state->event = NULL;
spin_unlock_irqrestore(&ddev->event_lock, flags);
}
static void tidss_crtc_atomic_enable(struct drm_crtc *crtc,
struct drm_atomic_state *state)
{
struct drm_crtc_state *old_state = drm_atomic_get_old_crtc_state(state,
crtc);
struct tidss_crtc *tcrtc = to_tidss_crtc(crtc);
struct drm_device *ddev = crtc->dev;
struct tidss_device *tidss = to_tidss(ddev);
const struct drm_display_mode *mode = &crtc->state->adjusted_mode;
unsigned long flags;
int r;
dev_dbg(ddev->dev, "%s, event %p\n", __func__, crtc->state->event);
tidss_runtime_get(tidss);
r = dispc_vp_set_clk_rate(tidss->dispc, tcrtc->hw_videoport,
mode->clock * 1000);
if (r != 0)
return;
r = dispc_vp_enable_clk(tidss->dispc, tcrtc->hw_videoport);
if (r != 0)
return;
dispc_vp_setup(tidss->dispc, tcrtc->hw_videoport, crtc->state, true);
tidss_crtc_position_planes(tidss, crtc, old_state, true);
/* Turn vertical blanking interrupt reporting on. */
drm_crtc_vblank_on(crtc);
dispc_vp_prepare(tidss->dispc, tcrtc->hw_videoport, crtc->state);
dispc_vp_enable(tidss->dispc, tcrtc->hw_videoport, crtc->state);
spin_lock_irqsave(&ddev->event_lock, flags);
if (crtc->state->event) {
drm_crtc_send_vblank_event(crtc, crtc->state->event);
crtc->state->event = NULL;
}
spin_unlock_irqrestore(&ddev->event_lock, flags);
}
static void tidss_crtc_atomic_disable(struct drm_crtc *crtc,
struct drm_atomic_state *state)
{
struct tidss_crtc *tcrtc = to_tidss_crtc(crtc);
struct drm_device *ddev = crtc->dev;
struct tidss_device *tidss = to_tidss(ddev);
unsigned long flags;
dev_dbg(ddev->dev, "%s, event %p\n", __func__, crtc->state->event);
reinit_completion(&tcrtc->framedone_completion);
/*
* If a layer is left enabled when the videoport is disabled, and the
* vid pipeline that was used for the layer is taken into use on
* another videoport, the DSS will report sync lost issues. Disable all
* the layers here as a work-around.
*/
for (u32 layer = 0; layer < tidss->feat->num_planes; layer++)
dispc_ovr_enable_layer(tidss->dispc, tcrtc->hw_videoport, layer,
false);
dispc_vp_disable(tidss->dispc, tcrtc->hw_videoport);
if (!wait_for_completion_timeout(&tcrtc->framedone_completion,
msecs_to_jiffies(500)))
dev_err(tidss->dev, "Timeout waiting for framedone on crtc %d",
tcrtc->hw_videoport);
dispc_vp_unprepare(tidss->dispc, tcrtc->hw_videoport);
spin_lock_irqsave(&ddev->event_lock, flags);
if (crtc->state->event) {
drm_crtc_send_vblank_event(crtc, crtc->state->event);
crtc->state->event = NULL;
}
spin_unlock_irqrestore(&ddev->event_lock, flags);
drm_crtc_vblank_off(crtc);
dispc_vp_disable_clk(tidss->dispc, tcrtc->hw_videoport);
tidss_runtime_put(tidss);
}
static
enum drm_mode_status tidss_crtc_mode_valid(struct drm_crtc *crtc,
const struct drm_display_mode *mode)
{
struct tidss_crtc *tcrtc = to_tidss_crtc(crtc);
struct drm_device *ddev = crtc->dev;
struct tidss_device *tidss = to_tidss(ddev);
return dispc_vp_mode_valid(tidss->dispc, tcrtc->hw_videoport, mode);
}
static const struct drm_crtc_helper_funcs tidss_crtc_helper_funcs = {
.atomic_check = tidss_crtc_atomic_check,
.atomic_flush = tidss_crtc_atomic_flush,
.atomic_enable = tidss_crtc_atomic_enable,
.atomic_disable = tidss_crtc_atomic_disable,
.mode_valid = tidss_crtc_mode_valid,
};
/* drm_crtc_funcs */
static int tidss_crtc_enable_vblank(struct drm_crtc *crtc)
{
struct drm_device *ddev = crtc->dev;
struct tidss_device *tidss = to_tidss(ddev);
dev_dbg(ddev->dev, "%s\n", __func__);
tidss_runtime_get(tidss);
tidss_irq_enable_vblank(crtc);
return 0;
}
static void tidss_crtc_disable_vblank(struct drm_crtc *crtc)
{
struct drm_device *ddev = crtc->dev;
struct tidss_device *tidss = to_tidss(ddev);
dev_dbg(ddev->dev, "%s\n", __func__);
tidss_irq_disable_vblank(crtc);
tidss_runtime_put(tidss);
}
static void tidss_crtc_reset(struct drm_crtc *crtc)
{
struct tidss_crtc_state *tcrtc;
if (crtc->state)
__drm_atomic_helper_crtc_destroy_state(crtc->state);
kfree(crtc->state);
tcrtc = kzalloc(sizeof(*tcrtc), GFP_KERNEL);
if (!tcrtc) {
crtc->state = NULL;
return;
}
__drm_atomic_helper_crtc_reset(crtc, &tcrtc->base);
}
static struct drm_crtc_state *tidss_crtc_duplicate_state(struct drm_crtc *crtc)
{
struct tidss_crtc_state *state, *current_state;
if (WARN_ON(!crtc->state))
return NULL;
current_state = to_tidss_crtc_state(crtc->state);
state = kmalloc(sizeof(*state), GFP_KERNEL);
if (!state)
return NULL;
__drm_atomic_helper_crtc_duplicate_state(crtc, &state->base);
state->plane_pos_changed = false;
state->bus_format = current_state->bus_format;
state->bus_flags = current_state->bus_flags;
return &state->base;
}
static void tidss_crtc_destroy(struct drm_crtc *crtc)
{
struct tidss_crtc *tcrtc = to_tidss_crtc(crtc);
drm_crtc_cleanup(crtc);
kfree(tcrtc);
}
static const struct drm_crtc_funcs tidss_crtc_funcs = {
.reset = tidss_crtc_reset,
.destroy = tidss_crtc_destroy,
.set_config = drm_atomic_helper_set_config,
.page_flip = drm_atomic_helper_page_flip,
.atomic_duplicate_state = tidss_crtc_duplicate_state,
.atomic_destroy_state = drm_atomic_helper_crtc_destroy_state,
.enable_vblank = tidss_crtc_enable_vblank,
.disable_vblank = tidss_crtc_disable_vblank,
};
struct tidss_crtc *tidss_crtc_create(struct tidss_device *tidss,
u32 hw_videoport,
struct drm_plane *primary)
{
struct tidss_crtc *tcrtc;
struct drm_crtc *crtc;
unsigned int gamma_lut_size = 0;
bool has_ctm = tidss->feat->vp_feat.color.has_ctm;
int ret;
tcrtc = kzalloc(sizeof(*tcrtc), GFP_KERNEL);
if (!tcrtc)
return ERR_PTR(-ENOMEM);
tcrtc->hw_videoport = hw_videoport;
init_completion(&tcrtc->framedone_completion);
crtc = &tcrtc->crtc;
ret = drm_crtc_init_with_planes(&tidss->ddev, crtc, primary,
NULL, &tidss_crtc_funcs, NULL);
if (ret < 0) {
kfree(tcrtc);
return ERR_PTR(ret);
}
drm_crtc_helper_add(crtc, &tidss_crtc_helper_funcs);
/*
* The dispc gamma functions adapt to what ever size we ask
* from it no matter what HW supports. X-server assumes 256
* element gamma tables so lets use that.
*/
if (tidss->feat->vp_feat.color.gamma_size)
gamma_lut_size = 256;
drm_crtc_enable_color_mgmt(crtc, 0, has_ctm, gamma_lut_size);
if (gamma_lut_size)
drm_mode_crtc_set_gamma_size(crtc, gamma_lut_size);
return tcrtc;
}