[PATCH 5.10.y] drm/amdgpu: fix ACP MFD device leak on init failure

[Sasha Levin <sashal@kernel.org>]

From: Guangshuo Li <lgs201920130244@gmail.com>

[ Upstream commit f0013046151b7467e62c471c1c83d63ea255799c ]

acp_hw_init() registers ACP child devices with mfd_add_devices() before
attaching them to the ACP power domain and initializing the hardware.

If attaching a child to the power domain fails, or if the ACP reset or
clock enable operation times out, the failure path frees only the
source cell, resource, and platform-data allocations. The child
platform devices already registered by mfd_add_devices() remain
registered and are never released.

Remove the children from the power domain and unregister the MFD
devices on failures that occur after mfd_add_devices() succeeds. Keep
mfd_add_devices() failures on the existing cleanup path since the MFD
core already rolls back partially registered children itself.

The issue was identified by a static analysis tool I developed and
confirmed by manual review.

Fixes: 25030321ba28 ("drm/amd: add pm domain for ACP IP sub blocks")
Signed-off-by: Guangshuo Li <lgs201920130244@gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit 63da68d6a2279ec945581c990c5a59a5ae8b5560)
Cc: stable@vger.kernel.org
[ sashal: adapted the error-path changes to the single device_for_each_child() call in acp_hw_init(). ]
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_acp.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_acp.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_acp.c
index 173ac5677d467..0f359f1fb041b 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_acp.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_acp.c
@@ -354,7 +354,7 @@ static int acp_hw_init(void *handle)
 	r = device_for_each_child(adev->acp.parent, &adev->acp.acp_genpd->gpd,
 				  acp_genpd_add_device);
 	if (r)
-		goto failure;
+		goto failure_remove_mfd;
 
 	/* Assert Soft reset of ACP */
 	val = cgs_read_register(adev->acp.cgs_device, mmACP_SOFT_RESET);
@@ -371,7 +371,7 @@ static int acp_hw_init(void *handle)
 		if (--count == 0) {
 			dev_err(&adev->pdev->dev, "Failed to reset ACP\n");
 			r = -ETIMEDOUT;
-			goto failure;
+			goto failure_remove_mfd;
 		}
 		udelay(100);
 	}
@@ -389,7 +389,7 @@ static int acp_hw_init(void *handle)
 		if (--count == 0) {
 			dev_err(&adev->pdev->dev, "Failed to reset ACP\n");
 			r = -ETIMEDOUT;
-			goto failure;
+			goto failure_remove_mfd;
 		}
 		udelay(100);
 	}
@@ -399,6 +399,11 @@ static int acp_hw_init(void *handle)
 	cgs_write_register(adev->acp.cgs_device, mmACP_SOFT_RESET, val);
 	return 0;
 
+failure_remove_mfd:
+	device_for_each_child(adev->acp.parent, NULL,
+			      acp_genpd_remove_device);
+	mfd_remove_devices(adev->acp.parent);
+
 failure:
 	kfree(i2s_pdata);
 	kfree(adev->acp.acp_res);
-- 
2.53.0