On Friday 14 February 2014 01:59 PM, Tomi Valkeinen wrote:
Instead of relying on the OMAP specific
omap_pm_get_dev_context_loss_count() to detect register context loss, we
can achieve the same in a much simpler way by just observing the DISPC
registers.
We always set DISPC's load mode to LOAD_FRAME_ONLY, which is not the
reset value. Thus we can just observe the load mode to see if we have
lost register context.
Nice trick :p
Reviewed-by: Archit Taneja <archit@xxxxxx>
Archit
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@xxxxxx>
---
drivers/video/omap2/dss/dispc.c | 24 +++++++++++-------------
1 file changed, 11 insertions(+), 13 deletions(-)
diff --git a/drivers/video/omap2/dss/dispc.c b/drivers/video/omap2/dss/dispc.c
index bbeb8dd7f108..1659aa912d2b 100644
--- a/drivers/video/omap2/dss/dispc.c
+++ b/drivers/video/omap2/dss/dispc.c
@@ -100,8 +100,6 @@ static struct {
struct platform_device *pdev;
void __iomem *base;
- int ctx_loss_cnt;
-
int irq;
unsigned long core_clk_rate;
@@ -357,29 +355,20 @@ static void dispc_save_context(void)
if (dss_has_feature(FEAT_CORE_CLK_DIV))
SR(DIVISOR);
- dispc.ctx_loss_cnt = dss_get_ctx_loss_count();
dispc.ctx_valid = true;
- DSSDBG("context saved, ctx_loss_count %d\n", dispc.ctx_loss_cnt);
+ DSSDBG("context saved\n");
}
static void dispc_restore_context(void)
{
- int i, j, ctx;
+ int i, j;
DSSDBG("dispc_restore_context\n");
if (!dispc.ctx_valid)
return;
- ctx = dss_get_ctx_loss_count();
-
- if (ctx >= 0 && ctx == dispc.ctx_loss_cnt)
- return;
-
- DSSDBG("ctx_loss_count: saved %d, current %d\n",
- dispc.ctx_loss_cnt, ctx);
-
/*RR(IRQENABLE);*/
/*RR(CONTROL);*/
RR(CONFIG);
@@ -3768,6 +3757,15 @@ static int dispc_runtime_suspend(struct device *dev)
static int dispc_runtime_resume(struct device *dev)
{
+ /*
+ * The reset value for load mode is 0 (OMAP_DSS_LOAD_CLUT_AND_FRAME)
+ * but we always initialize it to 2 (OMAP_DSS_LOAD_FRAME_ONLY) in
+ * _omap_dispc_initial_config(). We can thus use it to detect if
+ * we have lost register context.
+ */
+ if (REG_GET(DISPC_CONFIG, 2, 1) == OMAP_DSS_LOAD_FRAME_ONLY)
+ return 0;
+
_omap_dispc_initial_config();
dispc_restore_context();
--
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