diff options
Diffstat (limited to 'drivers/gpu/drm')
| -rw-r--r-- | drivers/gpu/drm/exynos/exynos_drm_fimd.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/drivers/gpu/drm/exynos/exynos_drm_fimd.c b/drivers/gpu/drm/exynos/exynos_drm_fimd.c index 173ee97..bd30d0c 100644 --- a/drivers/gpu/drm/exynos/exynos_drm_fimd.c +++ b/drivers/gpu/drm/exynos/exynos_drm_fimd.c @@ -39,6 +39,7 @@ */ #define FIMD_DEFAULT_FRAMERATE 60 +#define MIN_FB_WIDTH_FOR_16WORD_BURST 128 /* position control register for hardware window 0, 2 ~ 4.*/ #define VIDOSD_A(win) (VIDOSD_BASE + 0x00 + (win) * 16) @@ -479,6 +480,19 @@ static void fimd_win_set_pixfmt(struct fimd_context *ctx, unsigned int win) DRM_DEBUG_KMS("bpp = %d\n", win_data->bpp); + /* + * In case of exynos, setting dma-burst to 16Word causes permanent + * tearing for very small buffers, e.g. cursor buffer. Burst Mode + * switching which is based on overlay size is not recommended as + * overlay size varies alot towards the end of the screen and rapid + * movement causes unstable DMA which results into iommu crash/tear. + */ + + if (win_data->fb_width < MIN_FB_WIDTH_FOR_16WORD_BURST) { + val &= ~WINCONx_BURSTLEN_MASK; + val |= WINCONx_BURSTLEN_4WORD; + } + writel(val, ctx->regs + WINCON(win)); } |
