[PATCH] drm/tilcdc: do the complete reset sequence if the LCDC is enabled
Emiliano Ingrassia
ingrassia at epigenesys.com
Tue Mar 28 08:11:31 UTC 2017
If the LCD controller was already enabled (e.g. by the bootloader),
do the complete software reset sequence to avoid time out while loading
the palette and a consequent time out waiting for vblank.
Signed-off-by: Emiliano Ingrassia <ingrassia at epigenesys.com>
---
drivers/gpu/drm/tilcdc/tilcdc_crtc.c | 23 +++++++++++++++++++++++
1 file changed, 23 insertions(+)
diff --git a/drivers/gpu/drm/tilcdc/tilcdc_crtc.c b/drivers/gpu/drm/tilcdc/tilcdc_crtc.c
index 3621ff42979f..589156b2f76c 100644
--- a/drivers/gpu/drm/tilcdc/tilcdc_crtc.c
+++ b/drivers/gpu/drm/tilcdc/tilcdc_crtc.c
@@ -208,10 +208,33 @@ static void reset(struct drm_crtc *crtc)
{
struct drm_device *dev = crtc->dev;
struct tilcdc_drm_private *priv = dev->dev_private;
+ struct tilcdc_crtc *tilcdc_crtc = to_tilcdc_crtc(crtc);
+ int ret;
if (priv->rev != 2)
return;
+ /*
+ * If the LCDC was already enabled (e.g. by the bootloader)
+ * do the complete software reset sequence.
+ */
+ if (tilcdc_read(dev, LCDC_RASTER_CTRL_REG) & LCDC_RASTER_ENABLE) {
+
+ /* Enable DMA Frame Done Interrupt */
+ tilcdc_write(dev, LCDC_INT_ENABLE_SET_REG, LCDC_FRAME_DONE);
+ tilcdc_clear_irqstatus(dev, 0xffffffff);
+
+ tilcdc_crtc->frame_done = false;
+ tilcdc_clear(dev, LCDC_RASTER_CTRL_REG, LCDC_RASTER_ENABLE);
+
+ ret = wait_event_timeout(tilcdc_crtc->frame_done_wq,
+ tilcdc_crtc->frame_done,
+ msecs_to_jiffies(500));
+ if (ret == 0)
+ dev_err(dev->dev, "%s: timeout waiting for framedone while resetting LCDC\n",
+ __func__);
+ }
+
tilcdc_set(dev, LCDC_CLK_RESET_REG, LCDC_CLK_MAIN_RESET);
usleep_range(250, 1000);
tilcdc_clear(dev, LCDC_CLK_RESET_REG, LCDC_CLK_MAIN_RESET);
--
2.11.0
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