Re: [PATCH v3 2/5] vgaarb: pass errors from pci_set_vga_state() up

["Ville Syrjälä" <ville.syrjala@linux.intel.com>]

On Sun, Mar 08, 2026 at 02:35:35AM +0900, Simon Richter wrote:
> pci_set_vga_state() returns an error code, which so far has been ignored by
> the only caller, __vga_tryget(), so forward it to the caller. As the return
> type of __vga_tryget() is a pointer, wrap the error in ERR_PTR().
> 
> Signed-off-by: Simon Richter <Simon.Richter@hogyros.de>
> ---
>  drivers/pci/vgaarb.c | 13 +++++++++++--
>  1 file changed, 11 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/pci/vgaarb.c b/drivers/pci/vgaarb.c
> index 22b2b6ebdefd..c360eee11dd9 100644
> --- a/drivers/pci/vgaarb.c
> +++ b/drivers/pci/vgaarb.c
> @@ -215,6 +215,7 @@ static struct vga_device *__vga_tryget(struct vga_device *vgadev,
>  	struct vga_device *conflict;
>  	unsigned int pci_bits;
>  	u32 flags = 0;
> +	int err;
>  
>  	/*
>  	 * Account for "normal" resources to lock. If we decode the legacy,
> @@ -307,7 +308,9 @@ static struct vga_device *__vga_tryget(struct vga_device *vgadev,
>  		if (change_bridge)
>  			flags |= PCI_VGA_STATE_CHANGE_BRIDGE;
>  
> -		pci_set_vga_state(conflict->pdev, false, pci_bits, flags);
> +		err = pci_set_vga_state(conflict->pdev, false, pci_bits, flags);
> +		if (err)
> +			return ERR_PTR(err);

I was thinking this one should never fail and maybe could warrant
a WARN, but uv_set_vga_state() involves some kind of BIOS call and
who knows what that does. So maybe a WARN isn't a good idea.

>  		conflict->owns &= ~match;
>  
>  		/* If we disabled normal decoding, reflect it in owns */
> @@ -337,7 +340,9 @@ static struct vga_device *__vga_tryget(struct vga_device *vgadev,
>  	if (wants & VGA_RSRC_LEGACY_MASK)
>  		flags |= PCI_VGA_STATE_CHANGE_BRIDGE;
>  
> -	pci_set_vga_state(vgadev->pdev, true, pci_bits, flags);
> +	err = pci_set_vga_state(vgadev->pdev, true, pci_bits, flags);
> +	if (err)
> +		return ERR_PTR(err);
>  
>  	vgadev->owns |= wants;
>  lock_them:
> @@ -455,6 +460,10 @@ int vga_get(struct pci_dev *pdev, unsigned int rsrc, int interruptible)
>  		}
>  		conflict = __vga_tryget(vgadev, rsrc);
>  		spin_unlock_irqrestore(&vga_lock, flags);
> +		if (IS_ERR(conflict)) {
> +			rc = PTR_ERR(conflict);
> +			break;
> +		}
>  		if (conflict == NULL)
>  			break;
>  
> -- 
> 2.47.3

-- 
Ville Syrjälä
Intel