drm/rockchip: analogix_dp: Refuse to enable PSR if panel doesn't support it

There's no point in enabling PSR when the panel doesn't support it.

This also avoids a problem when PSR gets enabled when a CRTC is being
disabled, because sometimes in that situation the DSP_HOLD_VALID_INTR
interrupt on which we wait will never arrive. This was observed on
RK3288 with a panel without PSR (veyron-jaq Chromebook).

It's very easy to reproduce by running the kms_rmfb test in IGT a few
times.

Cc: Yakir Yang <[email protected]>
Reviewed-by: Sean Paul <[email protected]>
Signed-off-by: Tomeu Vizoso <[email protected]>
Signed-off-by: Archit Taneja <[email protected]>
Link: http://patchwork.freedesktop.org/patch/msgid/[email protected]

diff --git a/drivers/gpu/drm/rockchip/analogix_dp-rockchip.c b/drivers/gpu/drm/rockchip/analogix_dp-rockchip.c
index e83be157cc2a5fd049b440a7cec830867096ccb9..8548e8271639c665be80420dc7e77905ded5cf9a 100644 (file)
--- a/drivers/gpu/drm/rockchip/analogix_dp-rockchip.c
+++ b/drivers/gpu/drm/rockchip/analogix_dp-rockchip.c
@@ -85,6 +85,9 @@ static void analogix_dp_psr_set(struct drm_encoder *encoder, bool enabled)
        struct rockchip_dp_device *dp = to_dp(encoder);
        unsigned long flags;
 
+       if (!analogix_dp_psr_supported(dp->dev))
+               return;
+
        dev_dbg(dp->dev, "%s PSR...\n", enabled ? "Entry" : "Exit");
 
        spin_lock_irqsave(&dp->psr_lock, flags);