[U-Boot] [PATCH v2 5/6] tegra: video: Always use write-through cache on LCD

Simon Glass
2016-05-08T22:55:21Z

This seems to give the best performance, so let's use it always.

Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Stephen Warren <swarren@nvidia.com>
---

Changes in v2: None

drivers/video/tegra.c | 21 +++------------------
1 file changed, 3 insertions(+), 18 deletions(-)

diff --git a/drivers/video/tegra.c b/drivers/video/tegra.c
index 5c48c3b..217f05f 100644
--- a/drivers/video/tegra.c
+++ b/drivers/video/tegra.c
@@ -22,15 +22,6 @@

DECLARE_GLOBAL_DATA_PTR;

-enum lcd_cache_t {
- FDT_LCD_CACHE_OFF = 0,
- FDT_LCD_CACHE_WRITE_THROUGH = 1 << 0,
- FDT_LCD_CACHE_WRITE_BACK = 1 << 1,
- FDT_LCD_CACHE_FLUSH = 1 << 2,
- FDT_LCD_CACHE_WRITE_BACK_FLUSH = FDT_LCD_CACHE_WRITE_BACK |
- FDT_LCD_CACHE_FLUSH,
-};
-
/* Information about the display controller */
struct tegra_lcd_priv {
int width; /* width in pixels */
@@ -41,7 +32,6 @@ struct tegra_lcd_priv {
struct disp_ctlr *disp; /* Display controller to use */
fdt_addr_t frame_buffer; /* Address of frame buffer */
unsigned pixel_clock; /* Pixel clock in Hz */
- enum lcd_cache_t cache_type;
};

enum {
@@ -310,7 +300,6 @@ static int tegra_lcd_probe(struct udevice *dev)
struct video_priv *uc_priv = dev_get_uclass_priv(dev);
struct tegra_lcd_priv *priv = dev_get_priv(dev);
const void *blob = gd->fdt_blob;
- int type = DCACHE_OFF;
int ret;

/* Initialize the Tegra display controller */
@@ -329,15 +318,11 @@ static int tegra_lcd_probe(struct udevice *dev)
return ret;
}

- /* Set up the LCD caching as requested */
- if (priv->cache_type & FDT_LCD_CACHE_WRITE_THROUGH)
- type = DCACHE_WRITETHROUGH;
- else if (priv->cache_type & FDT_LCD_CACHE_WRITE_BACK)
- type = DCACHE_WRITEBACK;
- mmu_set_region_dcache_behaviour(priv->frame_buffer, plat->size, type);
+ mmu_set_region_dcache_behaviour(priv->frame_buffer, plat->size,
+ DCACHE_WRITETHROUGH);

/* Enable flushing after LCD writes if requested */
- video_set_flush_dcache(dev, priv->cache_type & FDT_LCD_CACHE_FLUSH);
+ video_set_flush_dcache(dev, true);

uc_priv->xsize = priv->width;
uc_priv->ysize = priv->height;
--
2.8.0.rc3.226.g39d4020