Hi Yongzhi,
Thank you for the patch.
On Wed, Jan 19, 2022 at 07:36:00AM -0800, Yongzhi Liu wrote:
> pm_runtime_get_sync() will increase the rumtime PM counter
> even it returns an error. Thus a pairing decrement is needed
> to prevent refcount leak. Fix this by replacing this API with
> pm_runtime_resume_and_get(), which will not change the runtime
> PM counter on error. Besides, a matching decrement is needed
> on the error handling path to keep the counter balanced.
>
> Signed-off-by: Yongzhi Liu <lyz_cs@xxxxxxxxxx>
> ---
> drivers/gpu/drm/bridge/nwl-dsi.c | 17 +++++++++++------
> 1 file changed, 11 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/gpu/drm/bridge/nwl-dsi.c b/drivers/gpu/drm/bridge/nwl-dsi.c
> index 9282e61..e7dce5a 100644
> --- a/drivers/gpu/drm/bridge/nwl-dsi.c
> +++ b/drivers/gpu/drm/bridge/nwl-dsi.c
> @@ -862,18 +862,19 @@ nwl_dsi_bridge_mode_set(struct drm_bridge *bridge,
> memcpy(&dsi->mode, adjusted_mode, sizeof(dsi->mode));
> drm_mode_debug_printmodeline(adjusted_mode);
>
> - pm_runtime_get_sync(dev);
> + if (pm_runtime_resume_and_get(dev) < 0)
> + return;
>
> if (clk_prepare_enable(dsi->lcdif_clk) < 0)
> - return;
> + goto runtime_put;
> if (clk_prepare_enable(dsi->core_clk) < 0)
> - return;
> + goto runtime_put;
>
> /* Step 1 from DSI reset-out instructions */
> ret = reset_control_deassert(dsi->rst_pclk);
> if (ret < 0) {
> DRM_DEV_ERROR(dev, "Failed to deassert PCLK: %d\n", ret);
> - return;
> + goto runtime_put;
> }
>
> /* Step 2 from DSI reset-out instructions */
> @@ -883,13 +884,17 @@ nwl_dsi_bridge_mode_set(struct drm_bridge *bridge,
> ret = reset_control_deassert(dsi->rst_esc);
> if (ret < 0) {
> DRM_DEV_ERROR(dev, "Failed to deassert ESC: %d\n", ret);
> - return;
> + goto runtime_put;
> }
> ret = reset_control_deassert(dsi->rst_byte);
> if (ret < 0) {
> DRM_DEV_ERROR(dev, "Failed to deassert BYTE: %d\n", ret);
> - return;
> + goto runtime_put;
> }
You need a return here, otherwise you will unconditionally call
pm_runtime_put_sync() even on success.
> +
> +runtime_put:
> + pm_runtime_put_sync(dev);
> + return;
You can drop the return here.
> }
>
> static void
--
Regards,
Laurent Pinchart
