Re: [PATCH 5/6] OMAPDSS: DISPC: move fifo threhold calc to dispc.c

On Sat, 2012-01-14 at 01:30 +0530, Archit wrote:

Hi,

On Friday 13 January 2012 05:16 PM, Tomi Valkeinen wrote:

quoted

Move fifo threshold calculation into dispc.c, as the thresholds are
really dispc internal thing.

Signed-off-by: Tomi Valkeinen<redacted>

<snip>

quoted

diff --git a/drivers/video/omap2/dss/dsi.c b/drivers/video/omap2/dss/dsi.c
index 511ae2a..1cbb7a5 100644
--- a/drivers/video/omap2/dss/dsi.c
+++ b/drivers/video/omap2/dss/dsi.c

@@ -4524,14 +4524,6 @@ int omapdss_dsi_enable_te(struct omap_dss_device *dssdev, bool enable)
  }
  EXPORT_SYMBOL(omapdss_dsi_enable_te);

-void dsi_get_overlay_fifo_thresholds(enum omap_plane plane,
-		u32 fifo_size, u32 burst_size,
-		u32 *fifo_low, u32 *fifo_high)
-{
-	*fifo_high = fifo_size - burst_size;
-	*fifo_low = fifo_size - burst_size * 2;
-}

We are removing the special treatment for overlays connected to DSI done 
before. Won't this cause the issues you saw with DSI in OMAP3?

I added a FEAT_OMAP3_DSI_FIFO_BUG flag for OMAP3s, and changed the
dispc's fifo config function to:

void dispc_ovl_compute_fifo_thresholds(enum omap_plane plane,
		u32 *fifo_low, u32 *fifo_high, bool use_fifomerge)
{
	/*
	 * All sizes are in bytes. Both the buffer and burst are made of
	 * buffer_units, and the fifo thresholds must be buffer_unit aligned.
	 */

	unsigned buf_unit = dss_feat_get_buffer_size_unit();
	unsigned ovl_fifo_size, total_fifo_size, burst_size;
	int i;

	burst_size = dispc_ovl_get_burst_size(plane);
	ovl_fifo_size = dispc_ovl_get_fifo_size(plane);

	if (use_fifomerge) {
		total_fifo_size = 0;
		for (i = 0; i < omap_dss_get_num_overlays(); ++i)
			total_fifo_size += dispc_ovl_get_fifo_size(i);
	} else {
		total_fifo_size = ovl_fifo_size;
	}

	/*
	 * We use the same low threshold for both fifomerge and non-fifomerge
	 * cases, but for fifomerge we calculate the high threshold using the
	 * combined fifo size
	 */

	if (dss_has_feature(FEAT_OMAP3_DSI_FIFO_BUG)) {
		*fifo_low = ovl_fifo_size - burst_size * 2;
		*fifo_high = total_fifo_size - burst_size;
	} else {
		*fifo_low = ovl_fifo_size - burst_size;
		*fifo_high = total_fifo_size - buf_unit;
	}
}

 Tomi