[PATCH 6.12.y] drm/msm/hdmi: Handle msm_hdmi_power_on() errors during .atomic_pre_enable()

[Sasha Levin <sashal@kernel.org>]

From: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>

[ Upstream commit dd6ecace57851878e62367a6f1a26dd5b9aa217f ]

Properly handle power up failures during .atomic_pre_enable() by
aborting the .atomic_pre_enable() to avoid accessing registers why
blocks did not bring up.  Otherwise this could lead to imprecise aborts
when accessing MMIO while entire power domain is off.

Cc: <stable@vger.kernel.org>
Fixes: ba3d7bf3a7ab ("drm/msm/hdmi: Convert PHY files according to new design")
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Patchwork: https://patchwork.freedesktop.org/patch/752652/
Link: https://lore.kernel.org/r/20260911-drm-msm-hdmi-fixes-before-eliza-v4-2-87bdb9f1987f@oss.qualcomm.com
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
[ sashal: adapted atomic_pre_enable() error handling to pre_enable() with explicit regulator and multiple-clock cleanup ]
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/gpu/drm/msm/hdmi/hdmi_bridge.c | 30 +++++++++++++++++++++-----
 1 file changed, 25 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/msm/hdmi/hdmi_bridge.c b/drivers/gpu/drm/msm/hdmi/hdmi_bridge.c
index b4abac49f5d96..4b874b1c846ad 100644
--- a/drivers/gpu/drm/msm/hdmi/hdmi_bridge.c
+++ b/drivers/gpu/drm/msm/hdmi/hdmi_bridge.c
@@ -11,7 +11,7 @@
 #include "msm_kms.h"
 #include "hdmi.h"
 
-static void msm_hdmi_power_on(struct drm_bridge *bridge)
+static int msm_hdmi_power_on(struct drm_bridge *bridge)
 {
 	struct drm_device *dev = bridge->dev;
 	struct hdmi_bridge *hdmi_bridge = to_hdmi_bridge(bridge);
@@ -19,11 +19,15 @@ static void msm_hdmi_power_on(struct drm_bridge *bridge)
 	const struct hdmi_platform_config *config = hdmi->config;
 	int i, ret;
 
-	pm_runtime_get_sync(&hdmi->pdev->dev);
+	ret = pm_runtime_resume_and_get(&hdmi->pdev->dev);
+	if (ret)
+		return ret;
 
 	ret = regulator_bulk_enable(config->pwr_reg_cnt, hdmi->pwr_regs);
-	if (ret)
+	if (ret) {
 		DRM_DEV_ERROR(dev->dev, "failed to enable pwr regulator: %d\n", ret);
+		goto err_pm_put;
+	}
 
 	if (config->pwr_clk_cnt > 0) {
 		DBG("pixclock: %lu", hdmi->pixclock);
@@ -39,8 +43,19 @@ static void msm_hdmi_power_on(struct drm_bridge *bridge)
 		if (ret) {
 			DRM_DEV_ERROR(dev->dev, "failed to enable pwr clk: %s (%d)\n",
 					config->pwr_clk_names[i], ret);
+			goto err_clk_unprepare;
 		}
 	}
+
+	return 0;
+
+err_clk_unprepare:
+	for (; i > 0; i--)
+		clk_disable_unprepare(hdmi->pwr_clks[i - 1]);
+	regulator_bulk_disable(config->pwr_reg_cnt, hdmi->pwr_regs);
+err_pm_put:
+	pm_runtime_put(&hdmi->pdev->dev);
+	return ret;
 }
 
 static void power_off(struct drm_bridge *bridge)
@@ -135,8 +150,13 @@ static void msm_hdmi_bridge_pre_enable(struct drm_bridge *bridge)
 	DBG("power up");
 
 	if (!hdmi->power_on) {
-		msm_hdmi_phy_resource_enable(phy);
-		msm_hdmi_power_on(bridge);
+		if (msm_hdmi_phy_resource_enable(phy))
+			return;
+
+		if (msm_hdmi_power_on(bridge)) {
+			msm_hdmi_phy_resource_disable(phy);
+			return;
+		}
 		hdmi->power_on = true;
 		if (hdmi->hdmi_mode) {
 			msm_hdmi_config_avi_infoframe(hdmi);
-- 
2.53.0