From 34a515d27c6573b6f550877b30dd5e0f440c3d8f Mon Sep 17 00:00:00 2001 From: Stefan Agner Date: Mon, 4 Jan 2016 16:34:22 -0800 Subject: [PATCH 1/3] drm/fsl-dcu: do not update when modifying irq registers The IRQ status and mask registers are not "double buffered" according to the reference manual. Hence, there is no extra transfer/update write needed when modifying these registers. Signed-off-by: Stefan Agner --- drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c | 4 ---- 1 file changed, 4 deletions(-) diff --git a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c index e04efbed1a54f..cc2fde2ae5eff 100644 --- a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c +++ b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c @@ -59,8 +59,6 @@ static int fsl_dcu_drm_irq_init(struct drm_device *dev) regmap_write(fsl_dev->regmap, DCU_INT_STATUS, 0); regmap_write(fsl_dev->regmap, DCU_INT_MASK, ~0); - regmap_write(fsl_dev->regmap, DCU_UPDATE_MODE, - DCU_UPDATE_MODE_READREG); return ret; } @@ -139,8 +137,6 @@ static irqreturn_t fsl_dcu_drm_irq(int irq, void *arg) drm_handle_vblank(dev, 0); regmap_write(fsl_dev->regmap, DCU_INT_STATUS, int_status); - regmap_write(fsl_dev->regmap, DCU_UPDATE_MODE, - DCU_UPDATE_MODE_READREG); return IRQ_HANDLED; } From 93daeeca2c9472a47d419884a64f6ca2b7f006e4 Mon Sep 17 00:00:00 2001 From: Stefan Agner Date: Mon, 5 Sep 2016 19:05:12 -0700 Subject: [PATCH 2/3] drm/fsl-dcu: update all registers on flush Use the UPDATE_MODE READREG bit to initiate a register transfer on flush. This makes sure that we flush all registers only once for all planes. Signed-off-by: Stefan Agner --- drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_crtc.c | 5 +++++ drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_plane.c | 5 ----- 2 files changed, 5 insertions(+), 5 deletions(-) diff --git a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_crtc.c b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_crtc.c index b2d5e188b1b88..2ea9dbd9be302 100644 --- a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_crtc.c +++ b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_crtc.c @@ -25,8 +25,13 @@ static void fsl_dcu_drm_crtc_atomic_flush(struct drm_crtc *crtc, struct drm_crtc_state *old_crtc_state) { + struct drm_device *dev = crtc->dev; + struct fsl_dcu_drm_device *fsl_dev = dev->dev_private; struct drm_pending_vblank_event *event = crtc->state->event; + regmap_write(fsl_dev->regmap, + DCU_UPDATE_MODE, DCU_UPDATE_MODE_READREG); + if (event) { crtc->state->event = NULL; diff --git a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_plane.c b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_plane.c index 9e6f7d8112b32..a99f488474205 100644 --- a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_plane.c +++ b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_plane.c @@ -160,11 +160,6 @@ static void fsl_dcu_drm_plane_atomic_update(struct drm_plane *plane, DCU_LAYER_POST_SKIP(0) | DCU_LAYER_PRE_SKIP(0)); } - regmap_update_bits(fsl_dev->regmap, DCU_DCU_MODE, - DCU_MODE_DCU_MODE_MASK, - DCU_MODE_DCU_MODE(DCU_MODE_NORMAL)); - regmap_write(fsl_dev->regmap, - DCU_UPDATE_MODE, DCU_UPDATE_MODE_READREG); return; } From 3d6f37102bd6e4b55a7f336d44974c0bd1c22a15 Mon Sep 17 00:00:00 2001 From: Stefan Agner Date: Mon, 31 Oct 2016 09:51:19 -0700 Subject: [PATCH 3/3] drm/fsl-dcu: disable planes before disabling CRTC After disabling and reenabling the CRTC the DCU sometimes got stuck displaying the whole screen with a solid color. Disabling and reenabling the CRTC did not recover from the situation. This was often reproducable by just restarting the X-Server. The disabling sequence is not explicitly documented. But it turns out that disabling the planes before disabling the CRTC seems to prevent the above situation from happening. Use the callback ->atomic_disable instead of ->disable which allows to use the drm_atomic_helper_disable_planes_on_crtc() helper to disable planes before disabling the controller. Signed-off-by: Stefan Agner --- drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_crtc.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_crtc.c b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_crtc.c index 2ea9dbd9be302..deb57435cc897 100644 --- a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_crtc.c +++ b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_crtc.c @@ -44,11 +44,15 @@ static void fsl_dcu_drm_crtc_atomic_flush(struct drm_crtc *crtc, } } -static void fsl_dcu_drm_disable_crtc(struct drm_crtc *crtc) +static void fsl_dcu_drm_crtc_atomic_disable(struct drm_crtc *crtc, + struct drm_crtc_state *old_crtc_state) { struct drm_device *dev = crtc->dev; struct fsl_dcu_drm_device *fsl_dev = dev->dev_private; + /* always disable planes on the CRTC */ + drm_atomic_helper_disable_planes_on_crtc(old_crtc_state, true); + drm_crtc_vblank_off(crtc); regmap_update_bits(fsl_dev->regmap, DCU_DCU_MODE, @@ -127,8 +131,8 @@ static void fsl_dcu_drm_crtc_mode_set_nofb(struct drm_crtc *crtc) } static const struct drm_crtc_helper_funcs fsl_dcu_drm_crtc_helper_funcs = { + .atomic_disable = fsl_dcu_drm_crtc_atomic_disable, .atomic_flush = fsl_dcu_drm_crtc_atomic_flush, - .disable = fsl_dcu_drm_disable_crtc, .enable = fsl_dcu_drm_crtc_enable, .mode_set_nofb = fsl_dcu_drm_crtc_mode_set_nofb, };