[PATCH 2/2] drm/arm/komeda: fix ignored clk_prepare_enable() return value in resume

[Gustavo Kenji Mendonça Kaneko]

komeda_dev_resume() calls clk_prepare_enable() without checking the
return value. If the clock fails to enable, the function returns 0
(success) while IRQs are enabled and IOMMU is connected on potentially
unclocked hardware, causing undefined behavior on resume.

Propagate the error from clk_prepare_enable() and return early on
failure to prevent hardware access without a valid clock.

This issue was found by code review without access to Komeda hardware.

Signed-off-by: Gustavo Kenji Mendonça Kaneko <kaneko.dev@xxxxx>
---
 drivers/gpu/drm/arm/display/komeda/komeda_dev.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_dev.c b/drivers/gpu/drm/arm/display/komeda/komeda_dev.c
index 5ba62e637a61..9aad1d1d28ec 100644
--- a/drivers/gpu/drm/arm/display/komeda/komeda_dev.c
+++ b/drivers/gpu/drm/arm/display/komeda/komeda_dev.c
@@ -313,7 +313,11 @@ void komeda_dev_destroy(struct komeda_dev *mdev)
 
 int komeda_dev_resume(struct komeda_dev *mdev)
 {
-	clk_prepare_enable(mdev->aclk);
+	int err;
+
+	err = clk_prepare_enable(mdev->aclk);
+	if (err)
+		return err;
 
 	mdev->funcs->enable_irq(mdev);
 
-- 
2.54.0