[PATCH 2/4] media: mediatek: vcodec: fix possible unbalanced PM counter

Eugen Hristev
2023-12-13T12:20:37Z

It is possible that mtk_vcodec_enc_pw_on fails, and in that scenario
the PM counter is not incremented, and subsequent call to
mtk_vcodec_enc_pw_off decrements the counter, leading to a PM imbalance.
Fix by bailing out of venc_if_encode in the case when mtk_vcodec_enc_pw_on
fails.

Fixes: 4e855a6efa54 ("[media] vcodec: mediatek: Add Mediatek V4L2 Video Encoder Driver")
Signed-off-by: Eugen Hristev <eugen.hristev@collabora.com>
---
.../platform/mediatek/vcodec/encoder/mtk_vcodec_enc_pm.c | 4 +++-
.../platform/mediatek/vcodec/encoder/mtk_vcodec_enc_pm.h | 2 +-
drivers/media/platform/mediatek/vcodec/encoder/venc_drv_if.c | 5 ++++-
3 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/media/platform/mediatek/vcodec/encoder/mtk_vcodec_enc_pm.c b/drivers/media/platform/mediatek/vcodec/encoder/mtk_vcodec_enc_pm.c
index a22b7dfc656e..1a2b14a3e219 100644
--- a/drivers/media/platform/mediatek/vcodec/encoder/mtk_vcodec_enc_pm.c
+++ b/drivers/media/platform/mediatek/vcodec/encoder/mtk_vcodec_enc_pm.c
@@ -58,13 +58,15 @@ int mtk_vcodec_init_enc_clk(struct mtk_vcodec_enc_dev *mtkdev)
return 0;
}

-void mtk_vcodec_enc_pw_on(struct mtk_vcodec_pm *pm)
+int mtk_vcodec_enc_pw_on(struct mtk_vcodec_pm *pm)
{
int ret;

ret = pm_runtime_resume_and_get(pm->dev);
if (ret)
dev_err(pm->dev, "pm_runtime_resume_and_get fail: %d", ret);
+
+ return ret;
}

void mtk_vcodec_enc_pw_off(struct mtk_vcodec_pm *pm)
diff --git a/drivers/media/platform/mediatek/vcodec/encoder/mtk_vcodec_enc_pm.h b/drivers/media/platform/mediatek/vcodec/encoder/mtk_vcodec_enc_pm.h
index 157ea08ba9e3..2e28f25e36cc 100644
--- a/drivers/media/platform/mediatek/vcodec/encoder/mtk_vcodec_enc_pm.h
+++ b/drivers/media/platform/mediatek/vcodec/encoder/mtk_vcodec_enc_pm.h
@@ -10,7 +10,7 @@
#include "mtk_vcodec_enc_drv.h"

int mtk_vcodec_init_enc_clk(struct mtk_vcodec_enc_dev *dev);
-void mtk_vcodec_enc_pw_on(struct mtk_vcodec_pm *pm);
+int mtk_vcodec_enc_pw_on(struct mtk_vcodec_pm *pm);
void mtk_vcodec_enc_pw_off(struct mtk_vcodec_pm *pm);
void mtk_vcodec_enc_clock_on(struct mtk_vcodec_pm *pm);
void mtk_vcodec_enc_clock_off(struct mtk_vcodec_pm *pm);
diff --git a/drivers/media/platform/mediatek/vcodec/encoder/venc_drv_if.c b/drivers/media/platform/mediatek/vcodec/encoder/venc_drv_if.c
index c402a686f3cb..e83747b8d69a 100644
--- a/drivers/media/platform/mediatek/vcodec/encoder/venc_drv_if.c
+++ b/drivers/media/platform/mediatek/vcodec/encoder/venc_drv_if.c
@@ -64,7 +64,9 @@ int venc_if_encode(struct mtk_vcodec_enc_ctx *ctx,
ctx->dev->curr_ctx = ctx;
spin_unlock_irqrestore(&ctx->dev->irqlock, flags);

- mtk_vcodec_enc_pw_on(&ctx->dev->pm);
+ ret = mtk_vcodec_enc_pw_on(&ctx->dev->pm);
+ if (ret)
+ goto venc_if_encode_pw_on_err;
mtk_vcodec_enc_clock_on(&ctx->dev->pm);
ret = ctx->enc_if->encode(ctx->drv_handle, opt, frm_buf,
bs_buf, result);
@@ -75,6 +77,7 @@ int venc_if_encode(struct mtk_vcodec_enc_ctx *ctx,
ctx->dev->curr_ctx = NULL;
spin_unlock_irqrestore(&ctx->dev->irqlock, flags);

+venc_if_encode_pw_on_err:
mtk_venc_unlock(ctx);
return ret;
}
--
2.34.1