From 83c0bcb694be31dcd6c04bdd935b96a95a0af548 Mon Sep 17 00:00:00 2001 From: Lucas Stach Date: Wed, 19 Dec 2012 21:38:54 +0000 Subject: [PATCH] drm: tegra: protect DC register access with mutex Window properties are programmed through a shared aperture and have to happen atomically. Also we do the read-update-write dance on some of the shared regs. To make sure that different functions don't stumble over each other protect the register access with a mutex. Signed-off-by: Lucas Stach Signed-off-by: Dave Airlie --- drivers/gpu/drm/tegra/dc.c | 13 +++++++++++++ drivers/gpu/drm/tegra/drm.h | 1 + 2 files changed, 14 insertions(+) diff --git a/drivers/gpu/drm/tegra/dc.c b/drivers/gpu/drm/tegra/dc.c index 54683e430c77..b256574409e7 100644 --- a/drivers/gpu/drm/tegra/dc.c +++ b/drivers/gpu/drm/tegra/dc.c @@ -171,6 +171,8 @@ static int tegra_crtc_mode_set(struct drm_crtc *crtc, return err; } + mutex_lock(&dc->regs_mutex); + /* program display mode */ tegra_dc_set_timings(dc, mode); @@ -269,6 +271,8 @@ static int tegra_crtc_mode_set(struct drm_crtc *crtc, tegra_dc_writel(dc, 0xff00, DC_WIN_BLEND_NOKEY); tegra_dc_writel(dc, 0xff00, DC_WIN_BLEND_1WIN); + mutex_unlock(&dc->regs_mutex); + return 0; } @@ -287,6 +291,8 @@ static void tegra_crtc_prepare(struct drm_crtc *crtc) else syncpt = SYNCPT_VBLANK0; + mutex_lock(&dc->regs_mutex); + /* initialize display controller */ tegra_dc_writel(dc, 0x00000100, DC_CMD_GENERAL_INCR_SYNCPT_CNTRL); tegra_dc_writel(dc, 0x100 | syncpt, DC_CMD_CONT_SYNCPT_VSYNC); @@ -320,6 +326,8 @@ static void tegra_crtc_prepare(struct drm_crtc *crtc) value = VBLANK_INT | WIN_A_UF_INT | WIN_B_UF_INT | WIN_C_UF_INT; tegra_dc_writel(dc, value, DC_CMD_INT_ENABLE); + + mutex_unlock(&dc->regs_mutex); } static void tegra_crtc_commit(struct drm_crtc *crtc) @@ -330,6 +338,8 @@ static void tegra_crtc_commit(struct drm_crtc *crtc) update_mask = GENERAL_ACT_REQ | WIN_A_ACT_REQ; + mutex_lock(&dc->regs_mutex); + tegra_dc_writel(dc, update_mask << 8, DC_CMD_STATE_CONTROL); value = tegra_dc_readl(dc, DC_CMD_INT_ENABLE); @@ -341,6 +351,8 @@ static void tegra_crtc_commit(struct drm_crtc *crtc) tegra_dc_writel(dc, value, DC_CMD_INT_MASK); tegra_dc_writel(dc, update_mask, DC_CMD_STATE_CONTROL); + + mutex_unlock(&dc->regs_mutex); } static void tegra_crtc_load_lut(struct drm_crtc *crtc) @@ -747,6 +759,7 @@ static int tegra_dc_probe(struct platform_device *pdev) return -ENOMEM; INIT_LIST_HEAD(&dc->list); + mutex_init(&dc->regs_mutex); dc->dev = &pdev->dev; dc->clk = devm_clk_get(&pdev->dev, NULL); diff --git a/drivers/gpu/drm/tegra/drm.h b/drivers/gpu/drm/tegra/drm.h index 3a843a77ddc7..eae1f564b716 100644 --- a/drivers/gpu/drm/tegra/drm.h +++ b/drivers/gpu/drm/tegra/drm.h @@ -84,6 +84,7 @@ struct tegra_dc { struct clk *clk; + struct mutex regs_mutex; void __iomem *regs; int irq; -- 2.30.2