From f13bdbd1fb75d0a6901012ab01a34754b2a4c6cf Mon Sep 17 00:00:00 2001 From: Akshu Agrawal Date: Mon, 28 Apr 2014 21:26:39 +0900 Subject: [PATCH] drm/exynos: fimd: clear channel before enabling iommu If any fimd channel was already active, initializing iommu will result in a PAGE FAULT (e.e. u-boot could have turned on the display and not disabled it before the kernel starts). This patch checks if any channel is active before initializing iommu and disables it. Signed-off-by: Akshu Agrawal Signed-off-by: Prathyush K Signed-off-by: Inki Dae --- drivers/gpu/drm/exynos/exynos_drm_fimd.c | 69 +++++++++++++++++------- 1 file changed, 49 insertions(+), 20 deletions(-) diff --git a/drivers/gpu/drm/exynos/exynos_drm_fimd.c b/drivers/gpu/drm/exynos/exynos_drm_fimd.c index 40fd6ccfcd6f..99ae79e09e82 100644 --- a/drivers/gpu/drm/exynos/exynos_drm_fimd.c +++ b/drivers/gpu/drm/exynos/exynos_drm_fimd.c @@ -143,6 +143,48 @@ static inline struct fimd_driver_data *drm_fimd_get_driver_data( return (struct fimd_driver_data *)of_id->data; } +static void fimd_wait_for_vblank(struct exynos_drm_manager *mgr) +{ + struct fimd_context *ctx = mgr->ctx; + + if (ctx->suspended) + return; + + atomic_set(&ctx->wait_vsync_event, 1); + + /* + * wait for FIMD to signal VSYNC interrupt or return after + * timeout which is set to 50ms (refresh rate of 20). + */ + if (!wait_event_timeout(ctx->wait_vsync_queue, + !atomic_read(&ctx->wait_vsync_event), + HZ/20)) + DRM_DEBUG_KMS("vblank wait timed out.\n"); +} + + +static void fimd_clear_channel(struct exynos_drm_manager *mgr) +{ + struct fimd_context *ctx = mgr->ctx; + int win, ch_enabled = 0; + + DRM_DEBUG_KMS("%s\n", __FILE__); + + /* Check if any channel is enabled. */ + for (win = 0; win < WINDOWS_NR; win++) { + u32 val = readl(ctx->regs + SHADOWCON); + if (val & SHADOWCON_CHx_ENABLE(win)) { + val &= ~SHADOWCON_CHx_ENABLE(win); + writel(val, ctx->regs + SHADOWCON); + ch_enabled = 1; + } + } + + /* Wait for vsync, as disable channel takes effect at next vsync */ + if (ch_enabled) + fimd_wait_for_vblank(mgr); +} + static int fimd_mgr_initialize(struct exynos_drm_manager *mgr, struct drm_device *drm_dev, int pipe) { @@ -169,8 +211,14 @@ static int fimd_mgr_initialize(struct exynos_drm_manager *mgr, drm_dev->vblank_disable_allowed = true; /* attach this sub driver to iommu mapping if supported. */ - if (is_drm_iommu_supported(ctx->drm_dev)) + if (is_drm_iommu_supported(ctx->drm_dev)) { + /* + * If any channel is already active, iommu will throw + * a PAGE FAULT when enabled. So clear any channel if enabled. + */ + fimd_clear_channel(mgr); drm_iommu_attach_device(ctx->drm_dev, ctx->dev); + } return 0; } @@ -324,25 +372,6 @@ static void fimd_disable_vblank(struct exynos_drm_manager *mgr) } } -static void fimd_wait_for_vblank(struct exynos_drm_manager *mgr) -{ - struct fimd_context *ctx = mgr->ctx; - - if (ctx->suspended) - return; - - atomic_set(&ctx->wait_vsync_event, 1); - - /* - * wait for FIMD to signal VSYNC interrupt or return after - * timeout which is set to 50ms (refresh rate of 20). - */ - if (!wait_event_timeout(ctx->wait_vsync_queue, - !atomic_read(&ctx->wait_vsync_event), - HZ/20)) - DRM_DEBUG_KMS("vblank wait timed out.\n"); -} - static void fimd_win_mode_set(struct exynos_drm_manager *mgr, struct exynos_drm_overlay *overlay) {