OMAPDSS: DISPC: Add naive threshold calc for fifomerge
Take fifo merge into use by implementing a rather naive fifo merge
threshold calculation: keep the low threshold always the same, but
increase the high threshold when fifo merge is used.
This should greatly increase the time between pixel data fetches from
SDRAM, as the usable fifo size is much larger. However, it probably
won't help for fifo underflows, as the low threshols is kept the same.
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
diff --git a/drivers/video/omap2/dss/dispc.c b/drivers/video/omap2/dss/dispc.c
index a759722..374c987 100644
--- a/drivers/video/omap2/dss/dispc.c
+++ b/drivers/video/omap2/dss/dispc.c
@@ -1072,13 +1072,33 @@
*/
unsigned buf_unit = dss_feat_get_buffer_size_unit();
- unsigned fifo_size, burst_size;
+ unsigned ovl_fifo_size, total_fifo_size, burst_size;
+ int i;
burst_size = dispc_ovl_get_burst_size(plane);
- fifo_size = dispc_ovl_get_fifo_size(plane);
+ ovl_fifo_size = dispc_ovl_get_fifo_size(plane);
- *fifo_low = fifo_size - burst_size;
- *fifo_high = fifo_size - buf_unit;
+ 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;
+ }
}
static void dispc_ovl_set_fir(enum omap_plane plane,
diff --git a/drivers/video/omap2/dss/dss_features.c b/drivers/video/omap2/dss/dss_features.c
index c2456c5..419419a 100644
--- a/drivers/video/omap2/dss/dss_features.c
+++ b/drivers/video/omap2/dss/dss_features.c
@@ -370,7 +370,8 @@
FEAT_LINEBUFFERSPLIT | FEAT_RESIZECONF |
FEAT_DSI_PLL_FREQSEL | FEAT_DSI_REVERSE_TXCLKESC |
FEAT_VENC_REQUIRES_TV_DAC_CLK | FEAT_CPR | FEAT_PRELOAD |
- FEAT_FIR_COEF_V | FEAT_ALPHA_FIXED_ZORDER | FEAT_FIFO_MERGE,
+ FEAT_FIR_COEF_V | FEAT_ALPHA_FIXED_ZORDER | FEAT_FIFO_MERGE |
+ FEAT_OMAP3_DSI_FIFO_BUG,
.num_mgrs = 2,
.num_ovls = 3,
@@ -394,7 +395,8 @@
FEAT_ROWREPEATENABLE | FEAT_LINEBUFFERSPLIT |
FEAT_RESIZECONF | FEAT_DSI_PLL_PWR_BUG |
FEAT_DSI_PLL_FREQSEL | FEAT_CPR | FEAT_PRELOAD |
- FEAT_FIR_COEF_V | FEAT_ALPHA_FIXED_ZORDER | FEAT_FIFO_MERGE,
+ FEAT_FIR_COEF_V | FEAT_ALPHA_FIXED_ZORDER | FEAT_FIFO_MERGE |
+ FEAT_OMAP3_DSI_FIFO_BUG,
.num_mgrs = 2,
.num_ovls = 3,
diff --git a/drivers/video/omap2/dss/dss_features.h b/drivers/video/omap2/dss/dss_features.h
index 50caee9..5f9b821 100644
--- a/drivers/video/omap2/dss/dss_features.h
+++ b/drivers/video/omap2/dss/dss_features.h
@@ -59,6 +59,8 @@
FEAT_ALPHA_FIXED_ZORDER = 1 << 26,
FEAT_ALPHA_FREE_ZORDER = 1 << 27,
FEAT_FIFO_MERGE = 1 << 28,
+ /* An unknown HW bug causing the normal FIFO thresholds not to work */
+ FEAT_OMAP3_DSI_FIFO_BUG = 1 << 29,
};
/* DSS register field id */