video: Tegra: DP: fix unbal enable_irq at resume

To fix the "unbalanced enable for IRQ" stack dump when resuming from the LP0
suspend with no DP panel/monitor connected to the system. It happens when
the number of disable_irq() calling and enable_irq() calling do not match.
Also, this fix will update the connection status to recognize the unplugging
of DP panel/monitor during the suspend.
The stack dump takes 220mSec. This fix may help to reduce the LP0 suspend
resuming time.

bug 200034625
bug 200051954
bug 200070123
DEPENDS ON: <None>

Change-Id: I4cb9efe8c19ba46b94881c6a287db2f261b26937
Signed-off-by: Sungwook Kim <sungwookk@nvidia.com>
Reviewed-on: http://git-master/r/714561
Reviewed-by: Bob Johnston <bjohnston@nvidia.com>
Reviewed-by: Animesh Kishore <ankishore@nvidia.com>
Reviewed-by: Jon Mayo <jmayo@nvidia.com>

1 files changed, 7 insertions, 5 deletions

diff --git a/drivers/video/tegra/dc/dp.c b/drivers/video/tegra/dc/dp.c
index ab767306d..b7cfa8001 100644
--- a/drivers/video/tegra/dc/dp.c
+++ b/drivers/video/tegra/dc/dp.c
@@ -2419,6 +2419,7 @@ static void tegra_dc_dp_enable(struct tegra_dc *dc)
                 if (tegra_dp_hpd_plug(dp) < 0) {
                         dev_info(&dc->ndev->dev,
                                 "dp: no panel/monitor plugged\n");
+                        dc->connected = false; /* unplugged during suspend */
                         goto error_enable;
                 }
         }
@@ -2495,18 +2496,19 @@ static void tegra_dc_dp_disable(struct tegra_dc *dc)
 {
         struct tegra_dc_dp_data *dp = tegra_dc_get_outdata(dc);
 
-        if (!dp->enabled)
-                return;
-
-        cancel_work_sync(&dp->lt_work);
-
         tegra_dc_io_start(dc);
 
         tegra_dp_default_int(dp, false);
+        cancel_work_sync(&dp->lt_work);
 
         if (dp->dc->out->type != TEGRA_DC_OUT_FAKE_DP)
                 tegra_dp_disable_irq(dp->irq);
 
+        if (!dp->enabled) {
+                tegra_dc_io_end(dc);
+                return;
+        }
+
         tegra_dpaux_pad_power(dp->dc,
         dp->dc->ndev->id == 0 ? TEGRA_DPAUX_INSTANCE_0 : TEGRA_DPAUX_INSTANCE_1
                 , false);