[PATCH] drm/omap: Fix runtime PM imbalance in dsi_runtime_get

From: Dinghao Liu
Date: Fri Aug 21 2020 - 03:46:09 EST


pm_runtime_get_sync() increments the runtime PM usage counter
even when it returns an error code. However, users of
dsi_runtime_get(), a direct wrapper of pm_runtime_get_sync(),
assume that PM usage counter will not change on error. Thus a
pairing decrement is needed on the error handling path to keep
the counter balanced.

Fixes: 4fbafaf371be7 ("OMAP: DSS2: Use PM runtime & HWMOD support")
Signed-off-by: Dinghao Liu <dinghao.liu@xxxxxxxxxx>
---
drivers/gpu/drm/omapdrm/dss/dsi.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/omapdrm/dss/dsi.c b/drivers/gpu/drm/omapdrm/dss/dsi.c
index eeccf40bae41..973bfa14a104 100644
--- a/drivers/gpu/drm/omapdrm/dss/dsi.c
+++ b/drivers/gpu/drm/omapdrm/dss/dsi.c
@@ -1112,8 +1112,11 @@ static int dsi_runtime_get(struct dsi_data *dsi)
DSSDBG("dsi_runtime_get\n");

r = pm_runtime_get_sync(dsi->dev);
- WARN_ON(r < 0);
- return r < 0 ? r : 0;
+ if (WARN_ON(r < 0)) {
+ pm_runtime_put_noidle(dsi->dev);
+ return r;
+ }
+ return 0;
}

static void dsi_runtime_put(struct dsi_data *dsi)
--
2.17.1