From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752622AbeDEJwu (ORCPT ); Thu, 5 Apr 2018 05:52:50 -0400 Received: from bhuna.collabora.co.uk ([46.235.227.227]:32926 "EHLO bhuna.collabora.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752230AbeDEJvK (ORCPT ); Thu, 5 Apr 2018 05:51:10 -0400 From: Enric Balletbo i Serra To: architt@codeaurora.org, inki.dae@samsung.com, thierry.reding@gmail.com, hjc@rock-chips.com, seanpaul@chromium.org, airlied@linux.ie, tfiga@chromium.org, heiko@sntech.de Cc: dri-devel@lists.freedesktop.org, dianders@chromium.org, a.hajda@samsung.com, ykk@rock-chips.com, kernel@collabora.com, m.szyprowski@samsung.com, linux-samsung-soc@vger.kernel.org, jy0922.shim@samsung.com, rydberg@bitmath.org, krzk@kernel.org, linux-rockchip@lists.infradead.org, kgene@kernel.org, linux-input@vger.kernel.org, orjan.eide@arm.com, wxt@rock-chips.com, jeffy.chen@rock-chips.com, linux-arm-kernel@lists.infradead.org, mark.yao@rock-chips.com, wzz@rock-chips.com, hl@rock-chips.com, jingoohan1@gmail.com, sw0312.kim@samsung.com, linux-kernel@vger.kernel.org, kyungmin.park@samsung.com, Laurent.pinchart@ideasonboard.com, kuankuan.y@gmail.com, hshi@chromium.org, Enric Balletbo i Serra Subject: [PATCH v6 26/30] drm/rockchip: psr: Avoid redundant calls to .set() callback Date: Thu, 5 Apr 2018 11:49:56 +0200 Message-Id: <20180405095000.9756-27-enric.balletbo@collabora.com> X-Mailer: git-send-email 2.16.3 In-Reply-To: <20180405095000.9756-1-enric.balletbo@collabora.com> References: <20180405095000.9756-1-enric.balletbo@collabora.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Tomasz Figa 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. This lets us represent the hardware state by a simple boolean called "enabled" and, while at it, rename the misleading "active" boolean to "inhibit", which represents the purpose much better. Also, userspace can (and does) trigger the rockchip_drm_do_flush() path from drmModeDirtyFB() at any time, whether or the encoder is active. If no mode is set, we call into analogix_dp_psr_set() which returns -EINVAL because encoder->crtc is NULL. Avoid this by starting out with psr->allowed set to false. Signed-off-by: Kristian H. Kristensen Signed-off-by: Tomasz Figa Signed-off-by: Thierry Escande Signed-off-by: Enric Balletbo i Serra Tested-by: Marek Szyprowski --- drivers/gpu/drm/rockchip/rockchip_drm_psr.c | 79 +++++++++-------------------- 1 file changed, 23 insertions(+), 56 deletions(-) diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_psr.c b/drivers/gpu/drm/rockchip/rockchip_drm_psr.c index c8655e625ba2..448c5fde241c 100644 --- a/drivers/gpu/drm/rockchip/rockchip_drm_psr.c +++ b/drivers/gpu/drm/rockchip/rockchip_drm_psr.c @@ -22,19 +22,13 @@ #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; struct work_struct disable_work; @@ -78,52 +72,22 @@ 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; - - /* Already disabled in flush, change the state, but not the hardware */ - if (state == PSR_DISABLE && psr->state == PSR_FLUSH) { - psr->state = state; - return; - } + int ret; - /* Actually commit the state change to hardware */ - switch (state) { - case PSR_ENABLE: - if (psr->set(psr->encoder, true)) - return; - break; - - case PSR_DISABLE: - case PSR_FLUSH: - if (psr->set(psr->encoder, false)) - return; - break; - - default: - pr_err("%s: Unknown state %d\n", __func__, state); - return; - } + if (!psr->active) + return -EINVAL; - psr->state = state; -} + if (enable == psr->enabled) + return 0; -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); + ret = psr->set(psr->encoder, enable); + if (ret) + return ret; + + psr->enabled = enable; + return 0; } static void psr_flush_handler(struct work_struct *work) @@ -131,10 +95,8 @@ 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); } @@ -176,6 +138,7 @@ 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); cancel_work_sync(&psr->disable_work); @@ -187,8 +150,12 @@ EXPORT_SYMBOL(rockchip_drm_psr_deactivate); static void rockchip_drm_do_flush(struct psr_drv *psr) { cancel_delayed_work_sync(&psr->flush_work); - psr_set_state(psr, PSR_FLUSH); - mod_delayed_work(system_wq, &psr->flush_work, PSR_FLUSH_TIMEOUT_MS); + + 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); } /** @@ -355,8 +322,8 @@ int rockchip_drm_psr_register(struct drm_encoder *encoder, INIT_WORK(&psr->disable_work, psr_disable_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; -- 2.16.3 From mboxrd@z Thu Jan 1 00:00:00 1970 From: enric.balletbo@collabora.com (Enric Balletbo i Serra) Date: Thu, 5 Apr 2018 11:49:56 +0200 Subject: [PATCH v6 26/30] drm/rockchip: psr: Avoid redundant calls to .set() callback In-Reply-To: <20180405095000.9756-1-enric.balletbo@collabora.com> References: <20180405095000.9756-1-enric.balletbo@collabora.com> Message-ID: <20180405095000.9756-27-enric.balletbo@collabora.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org From: Tomasz Figa 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. This lets us represent the hardware state by a simple boolean called "enabled" and, while at it, rename the misleading "active" boolean to "inhibit", which represents the purpose much better. Also, userspace can (and does) trigger the rockchip_drm_do_flush() path from drmModeDirtyFB() at any time, whether or the encoder is active. If no mode is set, we call into analogix_dp_psr_set() which returns -EINVAL because encoder->crtc is NULL. Avoid this by starting out with psr->allowed set to false. Signed-off-by: Kristian H. Kristensen Signed-off-by: Tomasz Figa Signed-off-by: Thierry Escande Signed-off-by: Enric Balletbo i Serra Tested-by: Marek Szyprowski --- drivers/gpu/drm/rockchip/rockchip_drm_psr.c | 79 +++++++++-------------------- 1 file changed, 23 insertions(+), 56 deletions(-) diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_psr.c b/drivers/gpu/drm/rockchip/rockchip_drm_psr.c index c8655e625ba2..448c5fde241c 100644 --- a/drivers/gpu/drm/rockchip/rockchip_drm_psr.c +++ b/drivers/gpu/drm/rockchip/rockchip_drm_psr.c @@ -22,19 +22,13 @@ #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; struct work_struct disable_work; @@ -78,52 +72,22 @@ 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; - - /* Already disabled in flush, change the state, but not the hardware */ - if (state == PSR_DISABLE && psr->state == PSR_FLUSH) { - psr->state = state; - return; - } + int ret; - /* Actually commit the state change to hardware */ - switch (state) { - case PSR_ENABLE: - if (psr->set(psr->encoder, true)) - return; - break; - - case PSR_DISABLE: - case PSR_FLUSH: - if (psr->set(psr->encoder, false)) - return; - break; - - default: - pr_err("%s: Unknown state %d\n", __func__, state); - return; - } + if (!psr->active) + return -EINVAL; - psr->state = state; -} + if (enable == psr->enabled) + return 0; -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); + ret = psr->set(psr->encoder, enable); + if (ret) + return ret; + + psr->enabled = enable; + return 0; } static void psr_flush_handler(struct work_struct *work) @@ -131,10 +95,8 @@ 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); } @@ -176,6 +138,7 @@ 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); cancel_work_sync(&psr->disable_work); @@ -187,8 +150,12 @@ EXPORT_SYMBOL(rockchip_drm_psr_deactivate); static void rockchip_drm_do_flush(struct psr_drv *psr) { cancel_delayed_work_sync(&psr->flush_work); - psr_set_state(psr, PSR_FLUSH); - mod_delayed_work(system_wq, &psr->flush_work, PSR_FLUSH_TIMEOUT_MS); + + 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); } /** @@ -355,8 +322,8 @@ int rockchip_drm_psr_register(struct drm_encoder *encoder, INIT_WORK(&psr->disable_work, psr_disable_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; -- 2.16.3