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drm/rockchip: psr: Avoid redundant calls to .set() callback

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The first time after we call rockchip_drm_do_flush() after
rockchip_drm_psr_register(), we go from PSR_DISABLE to PSR_FLUSH. The
difference between PSR_DISABLE and PSR_FLUSH is whether or not we have a
delayed work pending - PSR is off in either state.  However
psr_set_state() only catches the transition from PSR_FLUSH to
PSR_DISABLE (which never happens), while going from PSR_DISABLE to
PSR_FLUSH triggers a call to psr->set() to disable PSR while it's
already disabled. This triggers the eDP PHY power-on sequence without
being shut down first and this seems to occasionally leave the encoder
unable to later enable PSR. Let's just simplify the state machine and
simply consider PSR_DISABLE and PSR_FLUSH the same state.

Signed-off-by: Tomasz Figa <tfiga@chromium.org>
Signed-off-by: Kristian H. Kristensen <hoegsberg@chromium.org>
Signed-off-by: Thierry Escande <thierry.escande@collabora.com>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180423105003.9004-25-enric.balletbo@collabora.com
This commit is contained in:
Tomasz Figa 2018-04-23 12:50:00 +02:00 committed by Andrzej Hajda
parent a4169609de
commit 39b138ea86
1 changed files with 23 additions and 55 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

78
drivers/gpu/drm/rockchip/rockchip_drm_psr.c
View file

@ -20,19 +20,13 @@
#define PSR_FLUSH_TIMEOUT_MS 100
enum psr_state {
PSR_FLUSH,
PSR_ENABLE,
PSR_DISABLE,
};
struct psr_drv {
struct list_head list;
struct drm_encoder *encoder;
struct mutex lock;
bool active;
enum psr_state state;
bool enabled;
struct delayed_work flush_work;
@ -73,52 +67,22 @@ out:
return psr;
}
static void psr_set_state_locked(struct psr_drv *psr, enum psr_state state)
static int psr_set_state_locked(struct psr_drv *psr, bool enable)
{
/*
* Allowed finite state machine:
*
* PSR_ENABLE < = = = = = > PSR_FLUSH
* | ^ |
* | | |
* v | |
* PSR_DISABLE < - - - - - - - - -
*/
if (state == psr->state || !psr->active)
return;
int ret;
/* Already disabled in flush, change the state, but not the hardware */
if (state == PSR_DISABLE && psr->state == PSR_FLUSH) {
psr->state = state;
return;
}
if (!psr->active)
return -EINVAL;
/* Actually commit the state change to hardware */
switch (state) {
case PSR_ENABLE:
if (psr->set(psr->encoder, true))
return;
break;
if (enable == psr->enabled)
return 0;
case PSR_DISABLE:
case PSR_FLUSH:
if (psr->set(psr->encoder, false))
return;
break;
ret = psr->set(psr->encoder, enable);
if (ret)
return ret;
default:
pr_err("%s: Unknown state %d\n", __func__, state);
return;
}
psr->state = state;
}
static void psr_set_state(struct psr_drv *psr, enum psr_state state)
{
mutex_lock(&psr->lock);
psr_set_state_locked(psr, state);
mutex_unlock(&psr->lock);
psr->enabled = enable;
return 0;
}
static void psr_flush_handler(struct work_struct *work)
@ -126,10 +90,8 @@ static void psr_flush_handler(struct work_struct *work)
struct psr_drv *psr = container_of(to_delayed_work(work),
struct psr_drv, flush_work);
/* If the state has changed since we initiated the flush, do nothing */
mutex_lock(&psr->lock);
if (psr->state == PSR_FLUSH)
psr_set_state_locked(psr, PSR_ENABLE);
psr_set_state_locked(psr, true);
mutex_unlock(&psr->lock);
}
@ -171,6 +133,7 @@ int rockchip_drm_psr_deactivate(struct drm_encoder *encoder)
mutex_lock(&psr->lock);
psr->active = false;
psr->enabled = false;
mutex_unlock(&psr->lock);
cancel_delayed_work_sync(&psr->flush_work);
@ -180,8 +143,13 @@ EXPORT_SYMBOL(rockchip_drm_psr_deactivate);
static void rockchip_drm_do_flush(struct psr_drv *psr)
{
psr_set_state(psr, PSR_FLUSH);
mod_delayed_work(system_wq, &psr->flush_work, PSR_FLUSH_TIMEOUT_MS);
cancel_delayed_work_sync(&psr->flush_work);
mutex_lock(&psr->lock);
if (!psr_set_state_locked(psr, false))
mod_delayed_work(system_wq, &psr->flush_work,
PSR_FLUSH_TIMEOUT_MS);
mutex_unlock(&psr->lock);
}
/**
@ -250,8 +218,8 @@ int rockchip_drm_psr_register(struct drm_encoder *encoder,
INIT_DELAYED_WORK(&psr->flush_work, psr_flush_handler);
mutex_init(&psr->lock);
psr->active = true;
psr->state = PSR_DISABLE;
psr->active = false;
psr->enabled = false;
psr->encoder = encoder;
psr->set = psr_set;