drm/tidss: Fix atomic_flush check

commit 95d4b471953411854f9c80b568da7fcf753f3801 upstream.

tidss_crtc_atomic_flush() checks if the crtc is enabled, and if not,
returns immediately as there's no reason to do any register changes.

However, the code checks for 'crtc->state->enable', which does not
reflect the actual HW state. We should instead look at the
'crtc->state->active' flag.

This causes the tidss_crtc_atomic_flush() to proceed with the flush even
if the active state is false, which then causes us to hit the
WARN_ON(!crtc->state->event) check.

Fix this by checking the active flag, and while at it, fix the related
debug print which had "active" and "needs modeset" wrong way.

Cc:  <stable@vger.kernel.org>
Fixes: 32a1795f57ee ("drm/tidss: New driver for TI Keystone platform Display SubSystem")
Reviewed-by: Aradhya Bhatia <a-bhatia1@ti.com>
Link: https://lore.kernel.org/r/20231109-tidss-probe-v2-10-ac91b5ea35c0@ideasonboard.com
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/gpu/drm/tidss/tidss_crtc.c b/drivers/gpu/drm/tidss/tidss_crtc.c
index 5e5e466..7c78c07 100644 (file)
--- a/drivers/gpu/drm/tidss/tidss_crtc.c
+++ b/drivers/gpu/drm/tidss/tidss_crtc.c
@@ -169,13 +169,13 @@ static void tidss_crtc_atomic_flush(struct drm_crtc *crtc,
        struct tidss_device *tidss = to_tidss(ddev);
        unsigned long flags;
 
-       dev_dbg(ddev->dev,
-               "%s: %s enabled %d, needs modeset %d, event %p\n", __func__,
-               crtc->name, drm_atomic_crtc_needs_modeset(crtc->state),
-               crtc->state->enable, crtc->state->event);
+       dev_dbg(ddev->dev, "%s: %s is %sactive, %s modeset, event %p\n",
+               __func__, crtc->name, crtc->state->active ? "" : "not ",
+               drm_atomic_crtc_needs_modeset(crtc->state) ? "needs" : "doesn't need",
+               crtc->state->event);
 
        /* There is nothing to do if CRTC is not going to be enabled. */
-       if (!crtc->state->enable)
+       if (!crtc->state->active)
                return;
 
        /*