linux-kernel - Re: [PATCH v1 1/2] mfd: ls2kbmc: Fully convert to use managed resources

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Message-ID: <20251113140317.GH1949330@google.com>
Date: Thu, 13 Nov 2025 14:03:17 +0000
From: Lee Jones <lee@...nel.org>
To: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
Cc: Binbin Zhou <zhoubinbin@...ngson.cn>, linux-kernel@...r.kernel.org,
	Chong Qiao <qiaochong@...ngson.cn>
Subject: Re: [PATCH v1 1/2] mfd: ls2kbmc: Fully convert to use managed
 resources

On Thu, 30 Oct 2025, Andy Shevchenko wrote:

> The mixing managed and non-managed resources lay lead to all possible

Nit: "The mixing of ... may lead"

"all" really?  Maybe drop that bit.

> use-after-free bugs. In this driver the problematic part is the configuration
> space bits that may just gone behind the functions back, e.g., when interrupt

"have gone", but is this the best way we can describe this?

> is being served. Fix this by switching to managed resources for PCI.
> 
> Fixes: 91a3e1f5453a ("mfd: ls2kbmc: Check for devm_mfd_add_devices() failure")
> Fixes: d952bba3fbb5 ("mfd: ls2kbmc: Add Loongson-2K BMC reset function support")
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
> ---
>  drivers/mfd/ls2k-bmc-core.c | 36 +++++++++---------------------------
>  1 file changed, 9 insertions(+), 27 deletions(-)
> 
> diff --git a/drivers/mfd/ls2k-bmc-core.c b/drivers/mfd/ls2k-bmc-core.c
> index 69387dad6661..616ff0a28b00 100644
> --- a/drivers/mfd/ls2k-bmc-core.c
> +++ b/drivers/mfd/ls2k-bmc-core.c
> @@ -464,25 +464,23 @@ static int ls2k_bmc_probe(struct pci_dev *dev, const struct pci_device_id *id)
>  	resource_size_t base;
>  	int ret;
>  
> -	ret = pci_enable_device(dev);
> +	ret = pcim_enable_device(dev);
>  	if (ret)
>  		return ret;
>  
>  	ddata = devm_kzalloc(&dev->dev, sizeof(*ddata), GFP_KERNEL);
> -	if (!ddata) {
> -		ret = -ENOMEM;
> -		goto disable_pci;
> -	}
> +	if (!ddata)
> +		return -ENOMEM;
>  
>  	ddata->dev = &dev->dev;
>  
>  	ret = ls2k_bmc_init(ddata);
>  	if (ret)
> -		goto disable_pci;
> +		return ret;
>  
>  	ret = ls2k_bmc_parse_mode(dev, &pd);
>  	if (ret)
> -		goto disable_pci;
> +		return ret;
>  
>  	ls2k_bmc_cells[LS2K_BMC_DISPLAY].platform_data = &pd;
>  	ls2k_bmc_cells[LS2K_BMC_DISPLAY].pdata_size = sizeof(pd);
> @@ -490,27 +488,12 @@ static int ls2k_bmc_probe(struct pci_dev *dev, const struct pci_device_id *id)
>  
>  	/* Remove conflicting efifb device */
>  	ret = aperture_remove_conflicting_devices(base, SZ_4M, "simple-framebuffer");
> -	if (ret) {
> -		dev_err(&dev->dev, "Failed to removed firmware framebuffers: %d\n", ret);
> -		goto disable_pci;
> -	}
> -
> -	ret = devm_mfd_add_devices(&dev->dev, PLATFORM_DEVID_AUTO,
> -				   ls2k_bmc_cells, ARRAY_SIZE(ls2k_bmc_cells),
> -				   &dev->resource[0], 0, NULL);
>  	if (ret)
> -		goto disable_pci;
> +		return dev_err_probe(&dev->dev, ret, "Failed to removed firmware framebuffers\n");

Nit: May as well fix "remove".

... since the patch set doesn't apply.  Please rebase onto MFD or -next.

-- 
Lee Jones [李琼斯]