drm/exynos: use pm_runtime_resume_and_get()

Use pm_runtime_resume_and_get() instead of pm_runtime_get_sync()
to deal with usage counter. pm_runtime_get_sync() increases the
usage counter even when it failed, which makes callers to forget
to decrease the usage counter and resulted in reference leak.

pm_runtime_resume_and_get() function decreases the usage counter
when it failed internally so it can avoid the reference leak.

Changelog v1:
- Fix an build error reported by kernel test robot of Intel.

Signed-off-by: Inki Dae <inki.dae@samsung.com>
Reported-by: kernel test robot <lkp@intel.com>

1 files changed, 20 insertions, 5 deletions

diff --git a/drivers/gpu/drm/exynos/exynos_drm_fimd.c b/drivers/gpu/drm/exynos/exynos_drm_fimd.c
index ae576122873e..700ca4fa6665 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_fimd.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_fimd.c
@@ -343,13 +343,18 @@ static void fimd_enable_shadow_channel_path(struct fimd_context *ctx,
 	writel(val, ctx->regs + SHADOWCON);
 }
 
-static void fimd_clear_channels(struct exynos_drm_crtc *crtc)
+static int fimd_clear_channels(struct exynos_drm_crtc *crtc)
 {
 	struct fimd_context *ctx = crtc->ctx;
 	unsigned int win, ch_enabled = 0;
+	int ret;
 
 	/* Hardware is in unknown state, so ensure it gets enabled properly */
-	pm_runtime_get_sync(ctx->dev);
+	ret = pm_runtime_resume_and_get(ctx->dev);
+	if (ret < 0) {
+		dev_err(ctx->dev, "failed to enable FIMD device.\n");
+		return ret;
+	}
 
 	clk_prepare_enable(ctx->bus_clk);
 	clk_prepare_enable(ctx->lcd_clk);
@@ -384,6 +389,8 @@ static void fimd_clear_channels(struct exynos_drm_crtc *crtc)
 	clk_disable_unprepare(ctx->bus_clk);
 
 	pm_runtime_put(ctx->dev);
+
+	return 0;
 }
 
 
@@ -905,7 +912,10 @@ static void fimd_atomic_enable(struct exynos_drm_crtc *crtc)
 
 	ctx->suspended = false;
 
-	pm_runtime_get_sync(ctx->dev);
+	if (pm_runtime_resume_and_get(ctx->dev) < 0) {
+		dev_warn(ctx->dev, "failed to enable FIMD device.\n");
+		return;
+	}
 
 	/* if vblank was enabled status, enable it again. */
 	if (test_and_clear_bit(0, &ctx->irq_flags))
@@ -1089,8 +1099,13 @@ static int fimd_bind(struct device *dev, struct device *master, void *data)
 	if (ctx->encoder)
 		exynos_dpi_bind(drm_dev, ctx->encoder);
 
-	if (is_drm_iommu_supported(drm_dev))
-		fimd_clear_channels(ctx->crtc);
+	if (is_drm_iommu_supported(drm_dev)) {
+		int ret;
+
+		ret = fimd_clear_channels(ctx->crtc);
+		if (ret < 0)
+			return ret;
+	}
 
 	return exynos_drm_register_dma(drm_dev, dev, &ctx->dma_priv);
 }