[PATCH 5.16 030/285] drm/bridge: Add missing pm_runtime_put_sync

Greg Kroah-Hartman
2022-04-12T07:45:49Z

From: Yongzhi Liu <lyz_cs@pku.edu.cn>

[ Upstream commit 46f47807738441e354873546dde0b000106c068a ]

pm_runtime_get_sync() will increase the rumtime PM counter
even when 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@pku.edu.cn>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Robert Foss <robert.foss@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/1643008835-73961-1-git-send-email-lyz_cs@pku.edu.cn
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/gpu/drm/bridge/nwl-dsi.c | 18 ++++++++++++------
1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/bridge/nwl-dsi.c b/drivers/gpu/drm/bridge/nwl-dsi.c
index 6e484d836cfe..691039aba87f 100644
--- a/drivers/gpu/drm/bridge/nwl-dsi.c
+++ b/drivers/gpu/drm/bridge/nwl-dsi.c
@@ -861,18 +861,19 @@ 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 */
@@ -882,13 +883,18 @@ 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;
}
+
+ return;
+
+runtime_put:
+ pm_runtime_put_sync(dev);
}

static void
--
2.35.1