Re: [PATCH v5 1/7] media: platform: amd: Introduce amd isp4 capture driver

[Krzysztof Kozlowski <krzk@kernel.org>]

On 24/10/2025 11:06, Bin Du wrote:
> diff --git a/drivers/media/platform/amd/isp4/isp4.c b/drivers/media/platform/amd/isp4/isp4.c
> new file mode 100644
> index 000000000000..a3fc2462d70f
> --- /dev/null
> +++ b/drivers/media/platform/amd/isp4/isp4.c
> @@ -0,0 +1,121 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Copyright (C) 2025 Advanced Micro Devices, Inc.
> + */
> +
> +#include <linux/pm_runtime.h>
> +#include <linux/vmalloc.h>
> +#include <media/v4l2-ioctl.h>
> +
> +#include "isp4.h"
> +
> +#define VIDEO_BUF_NUM 5
> +
> +#define ISP4_DRV_NAME "amd_isp_capture"
> +
> +const char *isp4_irq_name[] = {

Why isn't this static?

> +	"isp_irq_stream1",
> +	"isp_irq_global"
> +};
> +
> +/* interrupt num */
> +static const u32 isp4_ringbuf_interrupt_num[] = {
> +	0, /* ISP_4_1__SRCID__ISP_RINGBUFFER_WPT9 */
> +	4, /* ISP_4_1__SRCID__ISP_RINGBUFFER_WPT12 */
> +};
> +
> +static irqreturn_t isp4_irq_handler(int irq, void *arg)
> +{
> +	return IRQ_HANDLED;
> +}
> +
> +static int isp4_capture_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct isp4_device *isp_dev;
> +	int i, irq, ret;
> +
> +	isp_dev = devm_kzalloc(dev, sizeof(*isp_dev), GFP_KERNEL);
> +	if (!isp_dev)
> +		return -ENOMEM;
> +
> +	isp_dev->pdev = pdev;
> +	dev->init_name = ISP4_DRV_NAME;
> +
> +	for (i = 0; i < ARRAY_SIZE(isp4_ringbuf_interrupt_num); i++) {
> +		irq = platform_get_irq(pdev, isp4_ringbuf_interrupt_num[i]);
> +		if (irq < 0)
> +			return dev_err_probe(dev, irq,
> +					     "fail to get irq %d\n",
> +					     isp4_ringbuf_interrupt_num[i]);
> +		ret = devm_request_irq(dev, irq, isp4_irq_handler, 0,
> +				       isp4_irq_name[i], dev);
> +		if (ret)
> +			return dev_err_probe(dev, ret, "fail to req irq %d\n",
> +					     irq);
> +	}
> +
> +	/* Link the media device within the v4l2_device */
> +	isp_dev->v4l2_dev.mdev = &isp_dev->mdev;
> +
> +	/* Initialize media device */
> +	strscpy(isp_dev->mdev.model, "amd_isp41_mdev",
> +		sizeof(isp_dev->mdev.model));
> +	snprintf(isp_dev->mdev.bus_info, sizeof(isp_dev->mdev.bus_info),
> +		 "platform:%s", ISP4_DRV_NAME);
> +	isp_dev->mdev.dev = dev;
> +	media_device_init(&isp_dev->mdev);
> +
> +	/* register v4l2 device */
> +	snprintf(isp_dev->v4l2_dev.name, sizeof(isp_dev->v4l2_dev.name),
> +		 "AMD-V4L2-ROOT");
> +	ret = v4l2_device_register(dev, &isp_dev->v4l2_dev);
> +	if (ret)
> +		return dev_err_probe(dev, ret,
> +				     "fail register v4l2 device\n");
> +
> +	ret = media_device_register(&isp_dev->mdev);
> +	if (ret) {
> +		dev_err(dev, "fail to register media device %d\n", ret);
> +		goto err_unreg_v4l2;
> +	}
> +
> +	platform_set_drvdata(pdev, isp_dev);
> +
> +	pm_runtime_set_suspended(dev);
> +	pm_runtime_enable(dev);
> +
> +	return 0;
> +
> +err_unreg_v4l2:
> +	v4l2_device_unregister(&isp_dev->v4l2_dev);
> +
> +	return dev_err_probe(dev, ret, "isp probe fail\n");

No, don't print generic error thus multiple errors. Drop this and keep
informative dev_err_probe() in applicable places.


> +}
> +
> +static void isp4_capture_remove(struct platform_device *pdev)
> +{
> +	struct isp4_device *isp_dev = platform_get_drvdata(pdev);
> +
> +	media_device_unregister(&isp_dev->mdev);
> +	v4l2_device_unregister(&isp_dev->v4l2_dev);
> +}
> +
> +static struct platform_driver isp4_capture_drv = {
> +	.probe = isp4_capture_probe,
> +	.remove = isp4_capture_remove,
> +	.driver = {
> +		.name = ISP4_DRV_NAME,
> +		.owner = THIS_MODULE,

It is v5 but you still did not run standard tools. You try to upstream
12 year old code without cleaning it up.

Please run standard kernel tools for static analysis, like coccinelle,
smatch and sparse, and fix reported warnings. Also please check for
warnings when building with W=1 for gcc and clang. Most of these
commands (checks or W=1 build) can build specific targets, like some
directory, to narrow the scope to only your code. The code here looks
like it needs a fix. Feel free to get in touch if the warning is not clear.

> +	}
> +};
> +
> +module_platform_driver(isp4_capture_drv);
> +
> +MODULE_ALIAS("platform:" ISP4_DRV_NAME);

You should not need MODULE_ALIAS() in normal cases. If you need it,
usually it means your device ID table is wrong (e.g. misses either
entries or MODULE_DEVICE_TABLE()). MODULE_ALIAS() is not a substitute
for incomplete ID table.


Best regards,
Krzysztof