Re: [PATCH v1] bus: mhi: host: Fix potential kernel panic by calling dev_err

[Krishna Chaitanya Chundru <krishna.chundru@oss.qualcomm.com>]

On 9/2/2025 10:26 PM, Adam Xue wrote:
> In mhi_init_irq_setup, the device pointer used for dev_err
> was not initialized. Use the pointer from pci_dev instead.
> 
> Signed-off-by: Adam Xue <zxue@semtech.com>
> ---
>   drivers/bus/mhi/host/init.c | 7 ++++---
>   1 file changed, 4 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/bus/mhi/host/init.c b/drivers/bus/mhi/host/init.c
> index 13e7a55f54ff..93eddf302a49 100644
> --- a/drivers/bus/mhi/host/init.c
> +++ b/drivers/bus/mhi/host/init.c
> @@ -18,6 +18,7 @@
>   #include <linux/slab.h>
>   #include <linux/vmalloc.h>
>   #include <linux/wait.h>
> +#include <linux/pci.h>
>   #include "internal.h"
>   
>   #define CREATE_TRACE_POINTS
> @@ -194,7 +195,7 @@ void mhi_deinit_free_irq(struct mhi_controller *mhi_cntrl)
>   int mhi_init_irq_setup(struct mhi_controller *mhi_cntrl)
>   {
>   	struct mhi_event *mhi_event = mhi_cntrl->mhi_event;
> -	struct device *dev = &mhi_cntrl->mhi_dev->dev;
> +	struct pci_dev *pdev = to_pci_dev(mhi_cntrl->cntrl_dev);
>   	unsigned long irq_flags = IRQF_SHARED | IRQF_NO_SUSPEND;
>   	int i, ret;
>   
> @@ -221,7 +222,7 @@ int mhi_init_irq_setup(struct mhi_controller *mhi_cntrl)
>   			continue;
>   
>   		if (mhi_event->irq >= mhi_cntrl->nr_irqs) {
> -			dev_err(dev, "irq %d not available for event ring\n",
> +			dev_err(&pdev->dev, "irq %d not available for event ring\n",
>   				mhi_event->irq);
Don't use pci_dev in mhi as mhi agnostic of the underlying transfer
protocol like PCIe.

Use dev_err(mhi_cntrl->cntrl_dev, here.

- Krishna Chaitanya.
>   			ret = -EINVAL;
>   			goto error_request;
> @@ -232,7 +233,7 @@ int mhi_init_irq_setup(struct mhi_controller *mhi_cntrl)
>   				  irq_flags,
>   				  "mhi", mhi_event);
>   		if (ret) {
> -			dev_err(dev, "Error requesting irq:%d for ev:%d\n",
> +			dev_err(&pdev->dev, "Error requesting irq:%d for ev:%d\n",
>   				mhi_cntrl->irq[mhi_event->irq], i);
>   			goto error_request;
>   		}