Hi Sean, Since 5.4-rc1 my Samsung Chromebook Plus (kevin) doesn't suspend/resume correctly, at least once every ten suspend/resume cycles the display doesn't turn on, and when this happens the kernel log message reports: [ 60.420230] PM: suspend exit [ 60.463866] rockchip-dp ff970000.edp: AUX CH cmd reply timeout! [ 60.971653] rockchip-dp ff970000.edp: AUX CH enable timeout! [ 61.478668] rockchip-dp ff970000.edp: AUX CH enable timeout! [ 61.985661] rockchip-dp ff970000.edp: AUX CH enable timeout! [ 62.492644] rockchip-dp ff970000.edp: AUX CH enable timeout! [ 62.999617] rockchip-dp ff970000.edp: AUX CH enable timeout! [ 63.506595] rockchip-dp ff970000.edp: AUX CH enable timeout! [ 64.013678] rockchip-dp ff970000.edp: AUX CH enable timeout! [ 64.522856] rockchip-dp ff970000.edp: AUX CH enable timeout! [ 60.463866] rockchip-dp ff970000.edp: AUX CH cmd reply timeout! [ 60.971653] rockchip-dp ff970000.edp: AUX CH enable timeout! [ 61.478668] rockchip-dp ff970000.edp: AUX CH enable timeout! [ 61.985661] rockchip-dp ff970000.edp: AUX CH enable timeout! [ 62.492644] rockchip-dp ff970000.edp: AUX CH enable timeout! ... Today I bisected the problem and pointed me to this commit. Reverting the commit fixes the issue, but from I quick look I don't see any obvious problem. I'll spend more time tomorrow looking at this but any idea will be welcome. Thanks, Enric Missatge de Sean Paul <sean@xxxxxxxxxx> del dia dj., 19 de set. 2019 a les 16:14: > > On Wed, Sep 18, 2019 at 04:07:29PM -0400, Sean Paul wrote: > > From: Sean Paul <seanpaul@xxxxxxxxxxxx> > > > > Currently the self refresh idle timer is a const set by the crtc. This > > is fine if the self refresh entry/exit times are well-known for all > > panels used on that crtc. However panels and workloads can vary quite a > > bit, and a timeout which works well for one doesn't work well for > > another. > > > > In the extreme, if the timeout is too short we could get in a situation > > where the self refresh exits are taking so long we queue up a self refresh > > entry before the exit commit is even finished. > > > > This patch changes the idle timeout to a moving average of the entry > > times + a moving average of exit times + the crtc constant. > > > > This patch was tested on rockchip, with a kevin CrOS panel the idle > > delay averages out to about ~235ms (35 entry + 100 exit + 100 const). On > > the same board, the bob panel idle delay lands around ~340ms (90 entry > > + 150 exit + 100 const). > > > > WRT the dedicated mutex in self_refresh_data, it would be nice if we > > could rely on drm_crtc.mutex to protect the average times, but there are > > a few reasons why a separate lock is a better choice: > > - We can't rely on drm_crtc.mutex being held if we're doing a nonblocking > > commit > > - We can't grab drm_crtc.mutex since drm_modeset_lock() doesn't tell us > > whether the lock was already held in the acquire context (it eats > > -EALREADY), so we can't tell if we should drop it or not > > - We don't need such a heavy-handed lock for what we're trying to do, > > commit ordering doesn't matter, so a point-of-use lock will be less > > contentious > > > > Reviewed-by: Daniel Vetter <daniel.vetter@xxxxxxxx> > > Pushed the first 2 to drm-misc-next-fixes to fix the gru-bob regression. I'll > fix up the 3rd patch separately. > > Thank you for the reviews! > > Sean > > > Signed-off-by: Sean Paul <seanpaul@xxxxxxxxxxxx> > > Link to v1: https://patchwork.freedesktop.org/patch/msgid/20190917200443.64481-2-sean@xxxxxxxxxx > > > > Changes in v2: > > - Migrate locking explanation from comment to commit msg (Daniel) > > - Turf constant entry delay and multiply the avg times by 2 (Daniel) > > --- > > drivers/gpu/drm/drm_atomic_helper.c | 20 ++++++ > > drivers/gpu/drm/drm_self_refresh_helper.c | 72 +++++++++++++++++++-- > > drivers/gpu/drm/rockchip/rockchip_drm_vop.c | 5 +- > > include/drm/drm_self_refresh_helper.h | 6 +- > > 4 files changed, 90 insertions(+), 13 deletions(-) > > > > diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c > > index 9d7e4da6c292..3f13fa9a9e24 100644 > > --- a/drivers/gpu/drm/drm_atomic_helper.c > > +++ b/drivers/gpu/drm/drm_atomic_helper.c > > @@ -26,6 +26,7 @@ > > */ > > > > #include <linux/dma-fence.h> > > +#include <linux/ktime.h> > > > > #include <drm/drm_atomic.h> > > #include <drm/drm_atomic_helper.h> > > @@ -1570,9 +1571,23 @@ static void commit_tail(struct drm_atomic_state *old_state) > > { > > struct drm_device *dev = old_state->dev; > > const struct drm_mode_config_helper_funcs *funcs; > > + ktime_t start; > > + s64 commit_time_ms; > > > > funcs = dev->mode_config.helper_private; > > > > + /* > > + * We're measuring the _entire_ commit, so the time will vary depending > > + * on how many fences and objects are involved. For the purposes of self > > + * refresh, this is desirable since it'll give us an idea of how > > + * congested things are. This will inform our decision on how often we > > + * should enter self refresh after idle. > > + * > > + * These times will be averaged out in the self refresh helpers to avoid > > + * overreacting over one outlier frame > > + */ > > + start = ktime_get(); > > + > > drm_atomic_helper_wait_for_fences(dev, old_state, false); > > > > drm_atomic_helper_wait_for_dependencies(old_state); > > @@ -1582,6 +1597,11 @@ static void commit_tail(struct drm_atomic_state *old_state) > > else > > drm_atomic_helper_commit_tail(old_state); > > > > + commit_time_ms = ktime_ms_delta(ktime_get(), start); > > + if (commit_time_ms > 0) > > + drm_self_refresh_helper_update_avg_times(old_state, > > + (unsigned long)commit_time_ms); > > + > > drm_atomic_helper_commit_cleanup_done(old_state); > > > > drm_atomic_state_put(old_state); > > diff --git a/drivers/gpu/drm/drm_self_refresh_helper.c b/drivers/gpu/drm/drm_self_refresh_helper.c > > index 9095cebf2147..68f4765a5896 100644 > > --- a/drivers/gpu/drm/drm_self_refresh_helper.c > > +++ b/drivers/gpu/drm/drm_self_refresh_helper.c > > @@ -5,6 +5,7 @@ > > * Authors: > > * Sean Paul <seanpaul@xxxxxxxxxxxx> > > */ > > +#include <linux/average.h> > > #include <linux/bitops.h> > > #include <linux/slab.h> > > #include <linux/workqueue.h> > > @@ -50,10 +51,17 @@ > > * atomic_check when &drm_crtc_state.self_refresh_active is true. > > */ > > > > +#define SELF_REFRESH_AVG_SEED_MS 200 > > + > > +DECLARE_EWMA(psr_time, 4, 4) > > + > > struct drm_self_refresh_data { > > struct drm_crtc *crtc; > > struct delayed_work entry_work; > > - unsigned int entry_delay_ms; > > + > > + struct mutex avg_mutex; > > + struct ewma_psr_time entry_avg_ms; > > + struct ewma_psr_time exit_avg_ms; > > }; > > > > static void drm_self_refresh_helper_entry_work(struct work_struct *work) > > @@ -121,6 +129,44 @@ static void drm_self_refresh_helper_entry_work(struct work_struct *work) > > drm_modeset_acquire_fini(&ctx); > > } > > > > +/** > > + * drm_self_refresh_helper_update_avg_times - Updates a crtc's SR time averages > > + * @state: the state which has just been applied to hardware > > + * @commit_time_ms: the amount of time in ms that this commit took to complete > > + * > > + * Called after &drm_mode_config_funcs.atomic_commit_tail, this function will > > + * update the average entry/exit self refresh times on self refresh transitions. > > + * These averages will be used when calculating how long to delay before > > + * entering self refresh mode after activity. > > + */ > > +void drm_self_refresh_helper_update_avg_times(struct drm_atomic_state *state, > > + unsigned int commit_time_ms) > > +{ > > + struct drm_crtc *crtc; > > + struct drm_crtc_state *old_crtc_state, *new_crtc_state; > > + int i; > > + > > + for_each_oldnew_crtc_in_state(state, crtc, old_crtc_state, > > + new_crtc_state, i) { > > + struct drm_self_refresh_data *sr_data = crtc->self_refresh_data; > > + struct ewma_psr_time *time; > > + > > + if (old_crtc_state->self_refresh_active == > > + new_crtc_state->self_refresh_active) > > + continue; > > + > > + if (new_crtc_state->self_refresh_active) > > + time = &sr_data->entry_avg_ms; > > + else > > + time = &sr_data->exit_avg_ms; > > + > > + mutex_lock(&sr_data->avg_mutex); > > + ewma_psr_time_add(time, commit_time_ms); > > + mutex_unlock(&sr_data->avg_mutex); > > + } > > +} > > +EXPORT_SYMBOL(drm_self_refresh_helper_update_avg_times); > > + > > /** > > * drm_self_refresh_helper_alter_state - Alters the atomic state for SR exit > > * @state: the state currently being checked > > @@ -152,6 +198,7 @@ void drm_self_refresh_helper_alter_state(struct drm_atomic_state *state) > > > > for_each_new_crtc_in_state(state, crtc, crtc_state, i) { > > struct drm_self_refresh_data *sr_data; > > + unsigned int delay; > > > > /* Don't trigger the entry timer when we're already in SR */ > > if (crtc_state->self_refresh_active) > > @@ -161,8 +208,13 @@ void drm_self_refresh_helper_alter_state(struct drm_atomic_state *state) > > if (!sr_data) > > continue; > > > > + mutex_lock(&sr_data->avg_mutex); > > + delay = (ewma_psr_time_read(&sr_data->entry_avg_ms) + > > + ewma_psr_time_read(&sr_data->exit_avg_ms)) * 2; > > + mutex_unlock(&sr_data->avg_mutex); > > + > > mod_delayed_work(system_wq, &sr_data->entry_work, > > - msecs_to_jiffies(sr_data->entry_delay_ms)); > > + msecs_to_jiffies(delay)); > > } > > } > > EXPORT_SYMBOL(drm_self_refresh_helper_alter_state); > > @@ -170,12 +222,10 @@ EXPORT_SYMBOL(drm_self_refresh_helper_alter_state); > > /** > > * drm_self_refresh_helper_init - Initializes self refresh helpers for a crtc > > * @crtc: the crtc which supports self refresh supported displays > > - * @entry_delay_ms: amount of inactivity to wait before entering self refresh > > * > > * Returns zero if successful or -errno on failure > > */ > > -int drm_self_refresh_helper_init(struct drm_crtc *crtc, > > - unsigned int entry_delay_ms) > > +int drm_self_refresh_helper_init(struct drm_crtc *crtc) > > { > > struct drm_self_refresh_data *sr_data = crtc->self_refresh_data; > > > > @@ -189,8 +239,18 @@ int drm_self_refresh_helper_init(struct drm_crtc *crtc, > > > > INIT_DELAYED_WORK(&sr_data->entry_work, > > drm_self_refresh_helper_entry_work); > > - sr_data->entry_delay_ms = entry_delay_ms; > > sr_data->crtc = crtc; > > + mutex_init(&sr_data->avg_mutex); > > + ewma_psr_time_init(&sr_data->entry_avg_ms); > > + ewma_psr_time_init(&sr_data->exit_avg_ms); > > + > > + /* > > + * Seed the averages so they're non-zero (and sufficiently large > > + * for even poorly performing panels). As time goes on, this will be > > + * averaged out and the values will trend to their true value. > > + */ > > + ewma_psr_time_add(&sr_data->entry_avg_ms, SELF_REFRESH_AVG_SEED_MS); > > + ewma_psr_time_add(&sr_data->exit_avg_ms, SELF_REFRESH_AVG_SEED_MS); > > > > crtc->self_refresh_data = sr_data; > > return 0; > > diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c > > index 2f821c58007c..613404f86668 100644 > > --- a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c > > +++ b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c > > @@ -39,8 +39,6 @@ > > #include "rockchip_drm_vop.h" > > #include "rockchip_rgb.h" > > > > -#define VOP_SELF_REFRESH_ENTRY_DELAY_MS 100 > > - > > #define VOP_WIN_SET(vop, win, name, v) \ > > vop_reg_set(vop, &win->phy->name, win->base, ~0, v, #name) > > #define VOP_SCL_SET(vop, win, name, v) \ > > @@ -1563,8 +1561,7 @@ static int vop_create_crtc(struct vop *vop) > > init_completion(&vop->line_flag_completion); > > crtc->port = port; > > > > - ret = drm_self_refresh_helper_init(crtc, > > - VOP_SELF_REFRESH_ENTRY_DELAY_MS); > > + ret = drm_self_refresh_helper_init(crtc); > > if (ret) > > DRM_DEV_DEBUG_KMS(vop->dev, > > "Failed to init %s with SR helpers %d, ignoring\n", > > diff --git a/include/drm/drm_self_refresh_helper.h b/include/drm/drm_self_refresh_helper.h > > index 397a583ccca7..5b79d253fb46 100644 > > --- a/include/drm/drm_self_refresh_helper.h > > +++ b/include/drm/drm_self_refresh_helper.h > > @@ -12,9 +12,9 @@ struct drm_atomic_state; > > struct drm_crtc; > > > > void drm_self_refresh_helper_alter_state(struct drm_atomic_state *state); > > +void drm_self_refresh_helper_update_avg_times(struct drm_atomic_state *state, > > + unsigned int commit_time_ms); > > > > -int drm_self_refresh_helper_init(struct drm_crtc *crtc, > > - unsigned int entry_delay_ms); > > - > > +int drm_self_refresh_helper_init(struct drm_crtc *crtc); > > void drm_self_refresh_helper_cleanup(struct drm_crtc *crtc); > > #endif > > -- > > Sean Paul, Software Engineer, Google / Chromium OS > > > > -- > Sean Paul, Software Engineer, Google / Chromium OS > _______________________________________________ > dri-devel mailing list > dri-devel@xxxxxxxxxxxxxxxxxxxxx > https://lists.freedesktop.org/mailman/listinfo/dri-devel _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
