drm/omap: fix output enable/disable sequence
At the moment it's quite easy to get the following errors when the HDMI
output is enabled or disabled:
[drm:omap_crtc_error_irq] *ERROR* tv: errors: 00008000
The reason for the errors is that the omapdrm driver doesn't properly
handle the sync-lost irqs that happen when enabling the DIGIT crtc,
which is used for HDMI and analog TV. The driver does disable the
sync-lost irq properly, but it fails to wait until the output has been
fully enabled (i.e. the first vsync), so the sync-lost errors are still
seen occasionally.
This patch makes the omapdrm act the same way as the omapfb does:
- When enabling a display, we'll wait for the first vsync.
- When disabling a display, we'll wait for framedone if available, or
odd and even vsyncs.
These changes make sure the output is fully enabled or disabled at the
end of the function.
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Reported-by: Sanjay Singh Rawat <sanjay.rawat@linaro.org>
Reviewed-by: Rob Clark <robdclark@gmail.com>
diff --git a/drivers/gpu/drm/omapdrm/omap_crtc.c b/drivers/gpu/drm/omapdrm/omap_crtc.c
index 355157e..0acbe62 100644
--- a/drivers/gpu/drm/omapdrm/omap_crtc.c
+++ b/drivers/gpu/drm/omapdrm/omap_crtc.c
@@ -528,38 +528,46 @@
struct drm_device *dev = crtc->dev;
struct omap_crtc *omap_crtc = to_omap_crtc(crtc);
enum omap_channel channel = omap_crtc->channel;
- struct omap_irq_wait *wait = NULL;
+ struct omap_irq_wait *wait;
+ u32 framedone_irq, vsync_irq;
+ int ret;
if (dispc_mgr_is_enabled(channel) == enable)
return;
- /* ignore sync-lost irqs during enable/disable */
+ /*
+ * Digit output produces some sync lost interrupts during the first
+ * frame when enabling, so we need to ignore those.
+ */
omap_irq_unregister(crtc->dev, &omap_crtc->error_irq);
- if (dispc_mgr_get_framedone_irq(channel)) {
- if (!enable) {
- wait = omap_irq_wait_init(dev,
- dispc_mgr_get_framedone_irq(channel), 1);
- }
+ framedone_irq = dispc_mgr_get_framedone_irq(channel);
+ vsync_irq = dispc_mgr_get_vsync_irq(channel);
+
+ if (enable) {
+ wait = omap_irq_wait_init(dev, vsync_irq, 1);
} else {
/*
- * When we disable digit output, we need to wait until fields
- * are done. Otherwise the DSS is still working, and turning
- * off the clocks prevents DSS from going to OFF mode. And when
- * enabling, we need to wait for the extra sync losts
+ * When we disable the digit output, we need to wait for
+ * FRAMEDONE to know that DISPC has finished with the output.
+ *
+ * OMAP2/3 does not have FRAMEDONE irq for digit output, and in
+ * that case we need to use vsync interrupt, and wait for both
+ * even and odd frames.
*/
- wait = omap_irq_wait_init(dev,
- dispc_mgr_get_vsync_irq(channel), 2);
+
+ if (framedone_irq)
+ wait = omap_irq_wait_init(dev, framedone_irq, 1);
+ else
+ wait = omap_irq_wait_init(dev, vsync_irq, 2);
}
dispc_mgr_enable(channel, enable);
- if (wait) {
- int ret = omap_irq_wait(dev, wait, msecs_to_jiffies(100));
- if (ret) {
- dev_err(dev->dev, "%s: timeout waiting for %s\n",
- omap_crtc->name, enable ? "enable" : "disable");
- }
+ ret = omap_irq_wait(dev, wait, msecs_to_jiffies(100));
+ if (ret) {
+ dev_err(dev->dev, "%s: timeout waiting for %s\n",
+ omap_crtc->name, enable ? "enable" : "disable");
}
omap_irq_register(crtc->dev, &omap_crtc->error_irq);