Re: [PATCH v2] vgaarb: Use dev_printk() when possible

[Daniel Vetter]

On Thu, Nov 17, 2016 at 11:47:58AM -0600, Bjorn Helgaas wrote:
> Use dev_printk() when possible.  This makes messages more consistent with
> other device-related messages and, in some cases, adds useful information.
> This changes messages like this:
> 
>   vgaarb: failed to allocate pci device
>   vgaarb: setting as boot device: PCI:0000:01:00.0
>   vgaarb: device added: PCI:0000:01:00.0,decodes=io+mem,owns=io+mem,locks=none
>   vgaarb: bridge control possible 0000:01:00.0
> 
> to this:
> 
>   pci 0000:01:00.0: vgaarb: failed to allocate VGA arbiter data
>   pci 0000:01:00.0: vgaarb: setting as boot VGA device
>   pci 0000:01:00.0: vgaarb: VGA device added: decodes=io+mem,owns=io+mem,locks=none
>   pci 0000:01:00.0: vgaarb: bridge control possible
> 
> No functional change intended.

Found one more nit below where there was one relevant change that
shouldn't be here.
-Daniel

> 
> Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
> ---
>  drivers/gpu/vga/vgaarb.c |   66 ++++++++++++++++++++++++----------------------
>  1 file changed, 35 insertions(+), 31 deletions(-)
> 
> diff --git a/drivers/gpu/vga/vgaarb.c b/drivers/gpu/vga/vgaarb.c
> index 1887f19..3a8e9c6 100644
> --- a/drivers/gpu/vga/vgaarb.c
> +++ b/drivers/gpu/vga/vgaarb.c
> @@ -31,6 +31,10 @@
>  
>  #define pr_fmt(fmt) "vgaarb: " fmt
>  
> +#define vgaarb_dbg(dev, fmt, arg...)	dev_dbg(dev, "vgaarb: " fmt, ##arg)
> +#define vgaarb_info(dev, fmt, arg...)	dev_info(dev, "vgaarb: " fmt, ##arg)
> +#define vgaarb_err(dev, fmt, arg...)	dev_err(dev, "vgaarb: " fmt, ##arg)
> +
>  #include <linux/module.h>
>  #include <linux/kernel.h>
>  #include <linux/pci.h>
> @@ -188,6 +192,7 @@ static void vga_check_first_use(void)
>  static struct vga_device *__vga_tryget(struct vga_device *vgadev,
>  				       unsigned int rsrc)
>  {
> +	struct device *dev = &vgadev->pdev->dev;
>  	unsigned int wants, legacy_wants, match;
>  	struct vga_device *conflict;
>  	unsigned int pci_bits;
> @@ -203,8 +208,8 @@ static struct vga_device *__vga_tryget(struct vga_device *vgadev,
>  	    (vgadev->decodes & VGA_RSRC_LEGACY_MEM))
>  		rsrc |= VGA_RSRC_LEGACY_MEM;
>  
> -	pr_debug("%s: %d\n", __func__, rsrc);
> -	pr_debug("%s: owns: %d\n", __func__, vgadev->owns);
> +	vgaarb_dbg(dev, "%s: %d\n", __func__, rsrc);
> +	vgaarb_dbg(dev, "%s: owns: %d\n", __func__, vgadev->owns);
>  
>  	/* Check what resources we need to acquire */
>  	wants = rsrc & ~vgadev->owns;
> @@ -336,9 +341,10 @@ static struct vga_device *__vga_tryget(struct vga_device *vgadev,
>  
>  static void __vga_put(struct vga_device *vgadev, unsigned int rsrc)
>  {
> +	struct device *dev = &vgadev->pdev->dev;
>  	unsigned int old_locks = vgadev->locks;
>  
> -	pr_debug("%s\n", __func__);
> +	vgaarb_dbg(dev, "%s\n", __func__);
>  
>  	/* Update our counters, and account for equivalent legacy resources
>  	 * if we decode them
> @@ -611,7 +617,7 @@ static bool vga_arbiter_add_pci_device(struct pci_dev *pdev)
>  	/* Allocate structure */
>  	vgadev = kzalloc(sizeof(struct vga_device), GFP_KERNEL);
>  	if (vgadev == NULL) {
> -		pr_err("failed to allocate pci device\n");
> +		vgaarb_err(&pdev->dev, "failed to allocate VGA arbiter data\n");
>  		/*
>  		 * What to do on allocation failure ? For now, let's just do
>  		 * nothing, I'm not sure there is anything saner to be done.
> @@ -663,7 +669,7 @@ static bool vga_arbiter_add_pci_device(struct pci_dev *pdev)
>  	 */
>  	if (vga_default == NULL &&
>  	    ((vgadev->owns & VGA_RSRC_LEGACY_MASK) == VGA_RSRC_LEGACY_MASK)) {
> -		pr_info("setting as boot device: PCI:%s\n", pci_name(pdev));
> +		vgaarb_info(&pdev->dev, "setting as boot VGA device\n");
>  		vga_set_default_device(pdev);
>  	}
>  
> @@ -672,8 +678,7 @@ static bool vga_arbiter_add_pci_device(struct pci_dev *pdev)
>  	/* Add to the list */
>  	list_add(&vgadev->list, &vga_list);
>  	vga_count++;
> -	pr_info("device added: PCI:%s,decodes=%s,owns=%s,locks=%s\n",
> -		pci_name(pdev),
> +	vgaarb_info(&pdev->dev, "VGA device added: decodes=%s,owns=%s,locks=%s\n",
>  		vga_iostate_to_str(vgadev->decodes),
>  		vga_iostate_to_str(vgadev->owns),
>  		vga_iostate_to_str(vgadev->locks));
> @@ -725,6 +730,7 @@ static bool vga_arbiter_del_pci_device(struct pci_dev *pdev)
>  static inline void vga_update_device_decodes(struct vga_device *vgadev,
>  					     int new_decodes)
>  {
> +	struct device *dev = &vgadev->pdev->dev;
>  	int old_decodes, decodes_removed, decodes_unlocked;
>  
>  	old_decodes = vgadev->decodes;
> @@ -732,8 +738,7 @@ static inline void vga_update_device_decodes(struct vga_device *vgadev,
>  	decodes_unlocked = vgadev->locks & decodes_removed;
>  	vgadev->decodes = new_decodes;
>  
> -	pr_info("device changed decodes: PCI:%s,olddecodes=%s,decodes=%s:owns=%s\n",
> -		pci_name(vgadev->pdev),
> +	vgaarb_info(dev, "changed VGA decodes: olddecodes=%s,decodes=%s:owns=%s\n",
>  		vga_iostate_to_str(old_decodes),
>  		vga_iostate_to_str(vgadev->decodes),
>  		vga_iostate_to_str(vgadev->owns));
> @@ -754,7 +759,7 @@ static inline void vga_update_device_decodes(struct vga_device *vgadev,
>  	if (!(old_decodes & VGA_RSRC_LEGACY_MASK) &&
>  	    new_decodes & VGA_RSRC_LEGACY_MASK)
>  		vga_decode_count++;
> -	pr_debug("decoding count now is: %d\n", vga_decode_count);
> +	vgaarb_dbg(dev, "decoding count now is: %d\n", vga_decode_count);
>  }
>  
>  static void __vga_set_legacy_decoding(struct pci_dev *pdev,
> @@ -1189,24 +1194,25 @@ static ssize_t vga_arb_write(struct file *file, const char __user *buf,
>  				ret_val = -EPROTO;
>  				goto done;
>  			}
> -			pr_debug("%s ==> %x:%x:%x.%x\n", curr_pos,
> -				domain, bus, PCI_SLOT(devfn), PCI_FUNC(devfn));
> -
>  			pdev = pci_get_domain_bus_and_slot(domain, bus, devfn);
> -			pr_debug("pdev %p\n", pdev);
>  			if (!pdev) {
> -				pr_err("invalid PCI address %x:%x:%x\n",
> -					domain, bus, devfn);
> +				pr_err("invalid PCI address %04x:%02x:%02x.%x\n",
> +					domain, bus, PCI_SLOT(devfn),
> +					PCI_FUNC(devfn));

Userspace-triggerable dmesg spam is imo not good, this needs to stay at
debug level.

>  				ret_val = -ENODEV;
>  				goto done;
>  			}
> +
> +			pr_debug("%s ==> %04x:%02x:%02x.%x pdev %p\n", curr_pos,
> +				domain, bus, PCI_SLOT(devfn), PCI_FUNC(devfn),
> +				pdev);
>  		}
>  
>  		vgadev = vgadev_find(pdev);
>  		pr_debug("vgadev %p\n", vgadev);
>  		if (vgadev == NULL) {
>  			if (pdev) {
> -				pr_err("this pci device is not a vga device\n");
> +				vgaarb_err(&pdev->dev, "not a VGA device\n");
>  				pci_dev_put(pdev);
>  			}
>  
> @@ -1226,7 +1232,7 @@ static ssize_t vga_arb_write(struct file *file, const char __user *buf,
>  			}
>  		}
>  		if (i == MAX_USER_CARDS) {
> -			pr_err("maximum user cards (%d) number reached!\n",
> +			vgaarb_err(&pdev->dev, "maximum user cards (%d) number reached, ignoring this one!\n",
>  				MAX_USER_CARDS);
>  			pci_dev_put(pdev);
>  			/* XXX: which value to return? */
> @@ -1317,8 +1323,8 @@ static int vga_arb_release(struct inode *inode, struct file *file)
>  		uc = &priv->cards[i];
>  		if (uc->pdev == NULL)
>  			continue;
> -		pr_debug("uc->io_cnt == %d, uc->mem_cnt == %d\n",
> -			 uc->io_cnt, uc->mem_cnt);
> +		vgaarb_dbg(&uc->pdev->dev, "uc->io_cnt == %d, uc->mem_cnt == %d\n",
> +			uc->io_cnt, uc->mem_cnt);
>  		while (uc->io_cnt--)
>  			vga_put(uc->pdev, VGA_RSRC_LEGACY_IO);
>  		while (uc->mem_cnt--)
> @@ -1371,7 +1377,7 @@ static int pci_notify(struct notifier_block *nb, unsigned long action,
>  	struct pci_dev *pdev = to_pci_dev(dev);
>  	bool notify = false;
>  
> -	pr_debug("%s\n", __func__);
> +	vgaarb_dbg(dev, "%s\n", __func__);
>  
>  	/* For now we're only intereted in devices added and removed. I didn't
>  	 * test this thing here, so someone needs to double check for the
> @@ -1408,6 +1414,7 @@ static int __init vga_arb_device_init(void)
>  	int rc;
>  	struct pci_dev *pdev;
>  	struct vga_device *vgadev;
> +	struct device *dev;
>  
>  	rc = misc_register(&vga_arb_device);
>  	if (rc < 0)
> @@ -1423,8 +1430,6 @@ static int __init vga_arb_device_init(void)
>  			       PCI_ANY_ID, pdev)) != NULL)
>  		vga_arbiter_add_pci_device(pdev);
>  
> -	pr_info("loaded\n");
> -
>  	list_for_each_entry(vgadev, &vga_list, list) {
>  #if defined(CONFIG_X86) || defined(CONFIG_IA64)
>  		/*
> @@ -1440,6 +1445,7 @@ static int __init vga_arb_device_init(void)
>  		int i;
>  
>  		limit = screen_info.lfb_base + screen_info.lfb_size;
> +		dev = &vgadev->pdev->dev;
>  
>  		/* Does firmware framebuffer belong to us? */
>  		for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) {
> @@ -1458,21 +1464,19 @@ static int __init vga_arb_device_init(void)
>  				continue;
>  
>  			if (!vga_default_device())
> -				pr_info("setting as boot device: PCI:%s\n",
> -					pci_name(vgadev->pdev));
> +				vgaarb_info(dev, "setting as boot device\n");
>  			else if (vgadev->pdev != vga_default_device())
> -				pr_info("overriding boot device: PCI:%s\n",
> -					pci_name(vgadev->pdev));
> +				vgaarb_info(dev, "overriding boot device\n");
>  			vga_set_default_device(vgadev->pdev);
>  		}
>  #endif
>  		if (vgadev->bridge_has_one_vga)
> -			pr_info("bridge control possible %s\n",
> -				pci_name(vgadev->pdev));
> +			vgaarb_info(dev, "bridge control possible\n");
>  		else
> -			pr_info("no bridge control possible %s\n",
> -				pci_name(vgadev->pdev));
> +			vgaarb_info(dev, "no bridge control possible\n");
>  	}
> +
> +	pr_info("loaded\n");
>  	return rc;
>  }
>  subsys_initcall(vga_arb_device_init);
> 
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-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch