[PATCH] drm/vc4: fix ref count leak in vc4_dsi_encoder_enable

From: Navid Emamdoost
Date: Sun Jun 14 2020 - 03:01:47 EST


in vc4_dsi_encoder_enable, the call to pm_runtime_get_sync increments
the counter even in case of failure, leading to incorrect
ref count. In case of failure, decrement the ref count before returning.

Signed-off-by: Navid Emamdoost <navid.emamdoost@xxxxxxxxx>
---
drivers/gpu/drm/vc4/vc4_dsi.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/vc4/vc4_dsi.c b/drivers/gpu/drm/vc4/vc4_dsi.c
index eaf276978ee7..e651de9d1c7d 100644
--- a/drivers/gpu/drm/vc4/vc4_dsi.c
+++ b/drivers/gpu/drm/vc4/vc4_dsi.c
@@ -838,7 +838,7 @@ static void vc4_dsi_encoder_enable(struct drm_encoder *encoder)
ret = pm_runtime_get_sync(dev);
if (ret) {
DRM_ERROR("Failed to runtime PM enable on DSI%d\n", dsi->port);
- return;
+ goto out;
}

if (debug_dump_regs) {
@@ -916,13 +916,13 @@ static void vc4_dsi_encoder_enable(struct drm_encoder *encoder)
ret = clk_prepare_enable(dsi->escape_clock);
if (ret) {
DRM_ERROR("Failed to turn on DSI escape clock: %d\n", ret);
- return;
+ goto out;
}

ret = clk_prepare_enable(dsi->pll_phy_clock);
if (ret) {
DRM_ERROR("Failed to turn on DSI PLL: %d\n", ret);
- return;
+ goto out;
}

hs_clock = clk_get_rate(dsi->pll_phy_clock);
@@ -944,7 +944,7 @@ static void vc4_dsi_encoder_enable(struct drm_encoder *encoder)
ret = clk_prepare_enable(dsi->pixel_clock);
if (ret) {
DRM_ERROR("Failed to turn on DSI pixel clock: %d\n", ret);
- return;
+ goto out;
}

/* How many ns one DSI unit interval is. Note that the clock
@@ -1088,6 +1088,8 @@ static void vc4_dsi_encoder_enable(struct drm_encoder *encoder)
dev_info(&dsi->pdev->dev, "DSI regs after:\n");
drm_print_regset32(&p, &dsi->regset);
}
+out:
+ pm_runtime_put(dev);
}

static ssize_t vc4_dsi_host_transfer(struct mipi_dsi_host *host,
--
2.17.1