From: Lucas Stach <l.st...@pengutronix.de>
Wait for both double buffer to be filled when first starting a channel.
This makes channel startup a lot more reliable, probably because it allows
the internal state machine to settle before the requests from the IPU are
coming in.
Signed-off-by: Lucas Stach <l.st...@pengutronix.de>
[p.za...@pengutronix.de: rebased before switch to runtime PM]
Signed-off-by: Philipp Zabel <p.za...@pengutronix.de>
---
drivers/gpu/ipu-v3/ipu-prg.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/drivers/gpu/ipu-v3/ipu-prg.c b/drivers/gpu/ipu-v3/ipu-prg.c
index ecc9ea44dc50f..0013ca9f72c83 100644
--- a/drivers/gpu/ipu-v3/ipu-prg.c
+++ b/drivers/gpu/ipu-v3/ipu-prg.c
@@ -14,6 +14,7 @@
#include <drm/drm_fourcc.h>
#include <linux/clk.h>
#include <linux/err.h>
+#include <linux/iopoll.h>
#include <linux/mfd/syscon.h>
#include <linux/mfd/syscon/imx6q-iomuxc-gpr.h>
#include <linux/module.h>
@@ -329,6 +330,12 @@ int ipu_prg_channel_configure(struct ipuv3_channel
*ipu_chan,
val = IPU_PRG_REG_UPDATE_REG_UPDATE;
writel(val, prg->regs + IPU_PRG_REG_UPDATE);
+ /* wait for both double buffers to be filled */
+ readl_poll_timeout(prg->regs + IPU_PRG_STATUS, val,
+ (val & IPU_PRG_STATUS_BUFFER0_READY(prg_chan)) &&
+ (val & IPU_PRG_STATUS_BUFFER1_READY(prg_chan)),
+ 5, 1000);
+
clk_disable_unprepare(prg->clk_ipg);
chan->enabled = true;
--
2.11.0
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel
