Re: [PATCH v6, 6/8] media: mediatek: vcodec: Refactor encoder clock on/off function

Ilpo Järvinen
2022-10-04T10:22:12Z

On Sat, 1 Oct 2022, Irui Wang wrote:

> when enable multi-core encoding, encoder cores use their own clock,
> refactor clock management functions with used encoder hardware id.
>
> Signed-off-by: Irui Wang <irui.wang@mediatek.com>
> ---
> .../mediatek/vcodec/mtk_vcodec_enc_pm.c | 89 ++++++++++++++++---
> .../mediatek/vcodec/mtk_vcodec_enc_pm.h | 6 +-
> .../platform/mediatek/vcodec/venc_drv_if.c | 4 +-
> 3 files changed, 84 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/media/platform/mediatek/vcodec/mtk_vcodec_enc_pm.c b/drivers/media/platform/mediatek/vcodec/mtk_vcodec_enc_pm.c
> index 213c3f50e9eb..2f83aade779a 100644
> --- a/drivers/media/platform/mediatek/vcodec/mtk_vcodec_enc_pm.c
> +++ b/drivers/media/platform/mediatek/vcodec/mtk_vcodec_enc_pm.c
> @@ -60,7 +60,9 @@ EXPORT_SYMBOL_GPL(mtk_vcodec_init_enc_clk);
> static int mtk_enc_core_power_on(struct mtk_vcodec_ctx *ctx)
> {
> struct mtk_venc_hw_dev *sub_core;
> + struct mtk_vcodec_clk *clk;
> int ret, i;
> + int j = 0;
>
> /* multi-core encoding need power on all available cores */
> for (i = 0; i < MTK_VENC_HW_MAX; i++) {
> @@ -73,12 +75,27 @@ static int mtk_enc_core_power_on(struct mtk_vcodec_ctx *ctx)
> mtk_v4l2_err("power on sub_core[%d] fail %d", i, ret);
> goto pm_on_fail;
> }
> +
> + clk = &sub_core->pm.venc_clk;
> + for (j = 0; j < clk->clk_num; j++) {
> + ret = clk_prepare(clk->clk_info[j].vcodec_clk);
> + if (ret) {
> + mtk_v4l2_err("prepare clk [%s] fail %d",
> + clk->clk_info[j].clk_name, ret);
> + goto pm_on_fail;
> + }
> + }
> }
> return ret;
>
> pm_on_fail:
> for (i -= 1; i >= 0; i--) {
> sub_core = (struct mtk_venc_hw_dev *)ctx->dev->enc_hw_dev[i];
> +
> + clk = &sub_core->pm.venc_clk;
> + for (j -= 1; j >= 0; j--)
> + clk_unprepare(clk->clk_info[j].vcodec_clk);
> +
> pm_runtime_put_sync(&sub_core->plat_dev->dev);

There's more than one thing wrong here.

pm_runtime_put_sync() won't be called for the ith entry when the later
goto pm_on_fail is taken because the loop decrements i right at the
start.

Similarly, i and j will mismatch for the ith entry because i was
decremented.

Third, j does not start from clk->clk_num - 1 for the other entries
(for those lower "i"s).

--
i.