From 39b138ea861a3494d2962467d6e275ae9f80a364 Mon Sep 17 00:00:00 2001 From: Tomasz Figa Date: Mon, 23 Apr 2018 12:50:00 +0200 Subject: [PATCH] drm/rockchip: psr: Avoid redundant calls to .set() callback 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 Signed-off-by: Kristian H. Kristensen Signed-off-by: Thierry Escande Signed-off-by: Enric Balletbo i Serra Tested-by: Marek Szyprowski Signed-off-by: Andrzej Hajda Link: https://patchwork.freedesktop.org/patch/msgid/20180423105003.9004-25-enric.balletbo@collabora.com --- drivers/gpu/drm/rockchip/rockchip_drm_psr.c | 78 ++++++--------------- 1 file changed, 23 insertions(+), 55 deletions(-) diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_psr.c b/drivers/gpu/drm/rockchip/rockchip_drm_psr.c index 9376f4396b6b..1a6157ffecec 100644 --- a/drivers/gpu/drm/rockchip/rockchip_drm_psr.c +++ b/drivers/gpu/drm/rockchip/rockchip_drm_psr.c @@ -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 @@ static struct psr_drv *find_psr_by_encoder(struct drm_encoder *encoder) 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;