From vulab at iscas.ac.cn  Tue Dec  2 01:52:52 2025
From: vulab at iscas.ac.cn (Haotian Zhang)
Date: Tue,  2 Dec 2025 17:52:52 +0800
Subject: [PATCH] staging: vc04_services: vchiq_bus: Check return value of of_dma_configure()
Message-ID: <20251202095253.1640-1-vulab@iscas.ac.cn>

vchiq_device_register() ignores the return value of of_dma_configure(),
which may return -EPROBE_DEFER when the IOMMU is not ready or other error
codes. This allows device registration to proceed with incomplete DMA
configuration.

Check of_dma_configure() return value and fail device registration
on error.

Fixes: 027e5703de6b ("staging: vc04_services: vchiq_arm: Add new bus type and device type")
Signed-off-by: Haotian Zhang <vulab at iscas.ac.cn>
---
 .../staging/vc04_services/interface/vchiq_arm/vchiq_bus.c  | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_bus.c b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_bus.c
index 41ece91ab88a..8d920a7a3777 100644
--- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_bus.c
+++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_bus.c
@@ -80,7 +80,12 @@ vchiq_device_register(struct device *parent, const char *name)
 
 	device->drv_mgmt = dev_get_drvdata(parent);
 
-	of_dma_configure(&device->dev, parent->of_node, true);
+	ret = of_dma_configure(&device->dev, parent->of_node, true);
+	if (ret) {
+		dev_err(parent, "DMA configuration failed for %s: %d\n", name, ret);
+		kfree(device);
+		return NULL;
+	}
 
 	ret = device_register(&device->dev);
 	if (ret) {
-- 
2.50.1.windows.1



From dan.carpenter at linaro.org  Tue Dec  2 02:18:10 2025
From: dan.carpenter at linaro.org (Dan Carpenter)
Date: Tue, 2 Dec 2025 13:18:10 +0300
Subject: [PATCH] staging: vc04_services: vchiq_bus: Check return value of
 of_dma_configure()
In-Reply-To: <20251202095253.1640-1-vulab@iscas.ac.cn>
References: <20251202095253.1640-1-vulab@iscas.ac.cn>
Message-ID: <aS684lo6j3ldvrPn@stanley.mountain>

You're not working against the latest tree so this doesn't apply.

On Tue, Dec 02, 2025 at 05:52:52PM +0800, Haotian Zhang wrote:
> vchiq_device_register() ignores the return value of of_dma_configure(),
> which may return -EPROBE_DEFER when the IOMMU is not ready or other error
> codes. This allows device registration to proceed with incomplete DMA
> configuration.
> 

If of_dma_configure() returns -EPROBE_DEFER then this will just fail and
that's not really any better than the existing behavior...

regards,
dan carpenter

> Check of_dma_configure() return value and fail device registration
> on error.
> 
> Fixes: 027e5703de6b ("staging: vc04_services: vchiq_arm: Add new bus type and device type")
> Signed-off-by: Haotian Zhang <vulab at iscas.ac.cn>