[PATCH] drm/tilcdc: restore correct display mode and contents on pm resume

From: Felipe Balbi
Date: Mon Mar 03 2014 - 14:10:44 EST


From: Darren Etheridge <detheridge@xxxxxx>

On resume the screen contents were not being restored properly. Looking at
other DRM drivers it seems a call to drm_helper_resume_force_mode() is needed
in the resume handler to force restoration of the mode and framebuffer data.

Signed-off-by: Darren Etheridge <detheridge@xxxxxx>
---
drivers/gpu/drm/tilcdc/tilcdc_drv.c | 7 +++++++
1 file changed, 7 insertions(+)

diff --git a/drivers/gpu/drm/tilcdc/tilcdc_drv.c b/drivers/gpu/drm/tilcdc/tilcdc_drv.c
index 171a820..1a5ddfa 100644
--- a/drivers/gpu/drm/tilcdc/tilcdc_drv.c
+++ b/drivers/gpu/drm/tilcdc/tilcdc_drv.c
@@ -563,6 +563,13 @@ static int tilcdc_pm_resume(struct device *dev)
if (registers[i].save && (priv->rev >= registers[i].rev))
tilcdc_write(ddev, registers[i].reg, priv->saved_register[n++]);

+ /*
+ * if this call isn't here, the display is blank on return from
+ * suspend. With this call here the contents of the framebuffer
+ * during suspend are restored correctly.
+ */
+ drm_helper_resume_force_mode(ddev);
+
drm_kms_helper_poll_enable(ddev);

return 0;
--
1.9.0

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