[PATCH v2] ARM: fix debug prints relevant to PCI devices

[PATCH v2] ARM: fix debug prints relevant to PCI devices

[Vidya Sagar]

As per PCIe spec, fast back-to-back transactions feature
is not applicable to PCIe devices. Hence, do not print
that fast back-to-back trasactions are disabled when
there is a PCIe device found on the bus

Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
---

v2:
* Modified has_pcie_dev type to bool and used pci_is_pcie() instead of pci_pcie_cap()
* replaced printk with pr_info

 arch/arm/kernel/bios32.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/arch/arm/kernel/bios32.c b/arch/arm/kernel/bios32.c
index 17a26c1..d48d9d3 100644
--- a/arch/arm/kernel/bios32.c
+++ b/arch/arm/kernel/bios32.c
@@ -290,6 +290,7 @@ void pcibios_fixup_bus(struct pci_bus *bus)
 {
 	struct pci_dev *dev;
 	u16 features = PCI_COMMAND_SERR | PCI_COMMAND_PARITY | PCI_COMMAND_FAST_BACK;
+	bool has_pcie_dev = 0;
 
 	/*
 	 * Walk the devices on this bus, working out what we can
@@ -298,6 +299,8 @@ void pcibios_fixup_bus(struct pci_bus *bus)
 	list_for_each_entry(dev, &bus->devices, bus_list) {
 		u16 status;
 
+		if (!has_pcie_dev)
+			has_pcie_dev = pci_is_pcie(dev);
 		pci_read_config_word(dev, PCI_STATUS, &status);
 
 		/*
@@ -354,9 +357,11 @@ void pcibios_fixup_bus(struct pci_bus *bus)
 
 	/*
 	 * Report what we did for this bus
+	 * (only if the bus doesn't have even one PCIe device)
 	 */
-	printk(KERN_INFO "PCI: bus%d: Fast back to back transfers %sabled\n",
-		bus->number, (features & PCI_COMMAND_FAST_BACK) ? "en" : "dis");
+	if (!has_pcie_dev)
+		pr_info(KERN_INFO "PCI: bus%d: Fast back to back transfers %sabled\n",
+			bus->number, (features & PCI_COMMAND_FAST_BACK) ? "en" : "dis");
 }
 EXPORT_SYMBOL(pcibios_fixup_bus);
 
-- 
1.8.1.5

Re: [PATCH v2] ARM: fix debug prints relevant to PCI devices

[Joe Perches]

On Fri, 2014-06-06 at 00:17 +0530, Vidya Sagar wrote:
> * replaced printk with pr_info
[]
> diff --git a/arch/arm/kernel/bios32.c b/arch/arm/kernel/bios32.c
[]
> @@ -354,9 +357,11 @@ void pcibios_fixup_bus(struct pci_bus *bus)
>  
>  	/*
>  	 * Report what we did for this bus
> +	 * (only if the bus doesn't have even one PCIe device)
>  	 */
> -	printk(KERN_INFO "PCI: bus%d: Fast back to back transfers %sabled\n",
> -		bus->number, (features & PCI_COMMAND_FAST_BACK) ? "en" : "dis");
> +	if (!has_pcie_dev)
> +		pr_info(KERN_INFO "PCI: bus%d: Fast back to back transfers %sabled\n",
> +			bus->number, (features & PCI_COMMAND_FAST_BACK) ? "en" : "dis");

when you convert to pr_<level> you need to remove the
KERN_<LEVEL> from the format string too.

RE: [PATCH v2] ARM: fix debug prints relevant to PCI devices

[Vidya Sagar]

oops... I missed it somehow. I'll post a new patch.

> -----Original Message-----
> From: Joe Perches [mailto:joe@perches.com]
> Sent: Friday, June 06, 2014 9:53 AM
> To: Vidya Sagar
> Cc: linux@arm.linux.org.uk; bhelgaas@google.com;
> wangyijing@huawei.com; thierry.reding@gmail.com;
> jason@lakedaemon.net; will.deacon@arm.com; Stephen Warren; Krishna
> Thota; sagar.tv@gmail.com; linux-arm-kernel@lists.infradead.org; linux-
> kernel@vger.kernel.org
> Subject: Re: [PATCH v2] ARM: fix debug prints relevant to PCI devices
> 
> On Fri, 2014-06-06 at 00:17 +0530, Vidya Sagar wrote:
> > * replaced printk with pr_info
> []
> > diff --git a/arch/arm/kernel/bios32.c b/arch/arm/kernel/bios32.c
> []
> > @@ -354,9 +357,11 @@ void pcibios_fixup_bus(struct pci_bus *bus)
> >
> >  	/*
> >  	 * Report what we did for this bus
> > +	 * (only if the bus doesn't have even one PCIe device)
> >  	 */
> > -	printk(KERN_INFO "PCI: bus%d: Fast back to back transfers
> %sabled\n",
> > -		bus->number, (features & PCI_COMMAND_FAST_BACK) ?
> "en" : "dis");
> > +	if (!has_pcie_dev)
> > +		pr_info(KERN_INFO "PCI: bus%d: Fast back to back transfers
> %sabled\n",
> > +			bus->number, (features &
> PCI_COMMAND_FAST_BACK) ? "en" : "dis");
> 
> when you convert to pr_<level> you need to remove the KERN_<LEVEL>
> from the format string too.
>