[RFC PATCH] arm: kernel: pci: remove pci=firmware command line parameter handling

[RFC PATCH] arm: kernel: pci: remove pci=firmware command line parameter handling

[Lorenzo Pieralisi]

According to kernel documentation, the pci=firmware command line
parameter is only meant to be used on IXP2000 ARM platforms to prevent
the kernel from assigning PCI resources configured by the bootloader.

Since the IXP2000 ARM platforms support has been removed from the
kernel in commit:

commit c65f2abf54a6 ("ARM: remove ixp23xx and ixp2000 platforms")

its platforms specific kernel parameters should be removed
too from the kernel documentation along with the kernel code
currently handling them in that they have just become obsolete.

This patch removes the pci=firmware command line parameter handling
from ARM code and the related kernel parameters documentation
section.

Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Lennert Buytenhek <kernel@wantstofly.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Rob Herring <robh@kernel.org>
Cc: Russell King <linux@arm.linux.org.uk>
---
 Documentation/kernel-parameters.txt | 5 -----
 arch/arm/kernel/bios32.c            | 3 ---
 2 files changed, 8 deletions(-)

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 9a53c92..e213acc 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -2875,11 +2875,6 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
 				for broken drivers that don't call it.
 		skip_isa_align	[X86] do not align io start addr, so can
 				handle more pci cards
-		firmware	[ARM] Do not re-enumerate the bus but instead
-				just use the configuration from the
-				bootloader. This is currently used on
-				IXP2000 systems where the bus has to be
-				configured a certain way for adjunct CPUs.
 		noearly		[X86] Don't do any early type 1 scanning.
 				This might help on some broken boards which
 				machine check when some devices' config space
diff --git a/arch/arm/kernel/bios32.c b/arch/arm/kernel/bios32.c
index 066f7f9..05e61a2 100644
--- a/arch/arm/kernel/bios32.c
+++ b/arch/arm/kernel/bios32.c
@@ -550,9 +550,6 @@ char * __init pcibios_setup(char *str)
 	if (!strcmp(str, "debug")) {
 		debug_pci = 1;
 		return NULL;
-	} else if (!strcmp(str, "firmware")) {
-		pci_add_flags(PCI_PROBE_ONLY);
-		return NULL;
 	}
 	return str;
 }
-- 
2.5.1

[RFC PATCH] arm: kernel: pci: remove pci=firmware command line parameter handling

[Lennert Buytenhek]

On Mon, Feb 29, 2016 at 05:43:20PM +0000, Lorenzo Pieralisi wrote:

> According to kernel documentation, the pci=firmware command line
> parameter is only meant to be used on IXP2000 ARM platforms to prevent
> the kernel from assigning PCI resources configured by the bootloader.
> 
> Since the IXP2000 ARM platforms support has been removed from the
> kernel in commit:
> 
> commit c65f2abf54a6 ("ARM: remove ixp23xx and ixp2000 platforms")
> 
> its platforms specific kernel parameters should be removed
> too from the kernel documentation along with the kernel code
> currently handling them in that they have just become obsolete.
> 
> This patch removes the pci=firmware command line parameter handling
> from ARM code and the related kernel parameters documentation
> section.
> 
> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
> Cc: Arnd Bergmann <arnd@arndb.de>
> Cc: Lennert Buytenhek <kernel@wantstofly.org>
> Cc: Jonathan Corbet <corbet@lwn.net>
> Cc: Bjorn Helgaas <bhelgaas@google.com>
> Cc: Rob Herring <robh@kernel.org>
> Cc: Russell King <linux@arm.linux.org.uk>

Acked-by: Lennert Buytenhek <kernel@wantstofly.org>

[RFC PATCH] arm: kernel: pci: remove pci=firmware command line parameter handling

[Lorenzo Pieralisi]

On Mon, Feb 29, 2016 at 07:42:58PM +0200, Lennert Buytenhek wrote:
> On Mon, Feb 29, 2016 at 05:43:20PM +0000, Lorenzo Pieralisi wrote:
> 
> > According to kernel documentation, the pci=firmware command line
> > parameter is only meant to be used on IXP2000 ARM platforms to prevent
> > the kernel from assigning PCI resources configured by the bootloader.
> > 
> > Since the IXP2000 ARM platforms support has been removed from the
> > kernel in commit:
> > 
> > commit c65f2abf54a6 ("ARM: remove ixp23xx and ixp2000 platforms")
> > 
> > its platforms specific kernel parameters should be removed
> > too from the kernel documentation along with the kernel code
> > currently handling them in that they have just become obsolete.
> > 
> > This patch removes the pci=firmware command line parameter handling
> > from ARM code and the related kernel parameters documentation
> > section.
> > 
> > Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
> > Cc: Arnd Bergmann <arnd@arndb.de>
> > Cc: Lennert Buytenhek <kernel@wantstofly.org>
> > Cc: Jonathan Corbet <corbet@lwn.net>
> > Cc: Bjorn Helgaas <bhelgaas@google.com>
> > Cc: Rob Herring <robh@kernel.org>
> > Cc: Russell King <linux@arm.linux.org.uk>
> 
> Acked-by: Lennert Buytenhek <kernel@wantstofly.org>

Thank you Lennert, I take this as an acknowledgement that you are not
aware of any other ARM platform using that kernel parameter other than
IXP2000s, according to documentation there should not be any but it is a
bit complicated to figure out.

Thanks,
Lorenzo

[RFC PATCH] arm: kernel: pci: remove pci=firmware command line parameter handling

[Lennert Buytenhek]

On Tue, Mar 01, 2016 at 09:58:33AM +0000, Lorenzo Pieralisi wrote:

> > > According to kernel documentation, the pci=firmware command line
> > > parameter is only meant to be used on IXP2000 ARM platforms to prevent
> > > the kernel from assigning PCI resources configured by the bootloader.
> > > 
> > > Since the IXP2000 ARM platforms support has been removed from the
> > > kernel in commit:
> > > 
> > > commit c65f2abf54a6 ("ARM: remove ixp23xx and ixp2000 platforms")
> > > 
> > > its platforms specific kernel parameters should be removed
> > > too from the kernel documentation along with the kernel code
> > > currently handling them in that they have just become obsolete.
> > > 
> > > This patch removes the pci=firmware command line parameter handling
> > > from ARM code and the related kernel parameters documentation
> > > section.
> > > 
> > > Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
> > > Cc: Arnd Bergmann <arnd@arndb.de>
> > > Cc: Lennert Buytenhek <kernel@wantstofly.org>
> > > Cc: Jonathan Corbet <corbet@lwn.net>
> > > Cc: Bjorn Helgaas <bhelgaas@google.com>
> > > Cc: Rob Herring <robh@kernel.org>
> > > Cc: Russell King <linux@arm.linux.org.uk>
> > 
> > Acked-by: Lennert Buytenhek <kernel@wantstofly.org>
> 
> Thank you Lennert, I take this as an acknowledgement that you are not
> aware of any other ARM platform using that kernel parameter other than
> IXP2000s, according to documentation there should not be any but it is a
> bit complicated to figure out.

I'm not aware of other platforms using this, but that might not say
much, I've been out of the loop on Linux/ARM things for a while now.

[RFC PATCH] arm: kernel: pci: remove pci=firmware command line parameter handling

[Lorenzo Pieralisi]

On Thu, Mar 03, 2016 at 12:31:42AM +0200, Lennert Buytenhek wrote:
> On Tue, Mar 01, 2016 at 09:58:33AM +0000, Lorenzo Pieralisi wrote:
> 
> > > > According to kernel documentation, the pci=firmware command line
> > > > parameter is only meant to be used on IXP2000 ARM platforms to prevent
> > > > the kernel from assigning PCI resources configured by the bootloader.
> > > > 
> > > > Since the IXP2000 ARM platforms support has been removed from the
> > > > kernel in commit:
> > > > 
> > > > commit c65f2abf54a6 ("ARM: remove ixp23xx and ixp2000 platforms")
> > > > 
> > > > its platforms specific kernel parameters should be removed
> > > > too from the kernel documentation along with the kernel code
> > > > currently handling them in that they have just become obsolete.
> > > > 
> > > > This patch removes the pci=firmware command line parameter handling
> > > > from ARM code and the related kernel parameters documentation
> > > > section.
> > > > 
> > > > Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
> > > > Cc: Arnd Bergmann <arnd@arndb.de>
> > > > Cc: Lennert Buytenhek <kernel@wantstofly.org>
> > > > Cc: Jonathan Corbet <corbet@lwn.net>
> > > > Cc: Bjorn Helgaas <bhelgaas@google.com>
> > > > Cc: Rob Herring <robh@kernel.org>
> > > > Cc: Russell King <linux@arm.linux.org.uk>
> > > 
> > > Acked-by: Lennert Buytenhek <kernel@wantstofly.org>
> > 
> > Thank you Lennert, I take this as an acknowledgement that you are not
> > aware of any other ARM platform using that kernel parameter other than
> > IXP2000s, according to documentation there should not be any but it is a
> > bit complicated to figure out.
> 
> I'm not aware of other platforms using this, but that might not say
> much, I've been out of the loop on Linux/ARM things for a while now.

I think we should go ahead otherwise we are stuck forever with it,
it is probably best for this patch to land in -next beginning of
next cycle to unearth possible issues, that's the same thing
we did for the latest changes in arm pcibios that we feared could
trigger regressions.

Russell, what's your opinion on this ? Please let me know.

Thanks !
Lorenzo

[RFC PATCH] arm: kernel: pci: remove pci=firmware command line parameter handling

[Russell King - ARM Linux]

On Thu, Mar 03, 2016 at 10:48:45AM +0000, Lorenzo Pieralisi wrote:
> I think we should go ahead otherwise we are stuck forever with it,
> it is probably best for this patch to land in -next beginning of
> next cycle to unearth possible issues, that's the same thing
> we did for the latest changes in arm pcibios that we feared could
> trigger regressions.
> 
> Russell, what's your opinion on this ? Please let me know.

I'm happy with the suggested approach.

Thanks.

-- 
RMK's Patch system: http://www.arm.linux.org.uk/developer/patches/
FTTC broadband for 0.8mile line: currently at 9.6Mbps down 400kbps up
according to speedtest.net.

[RFC PATCH] arm: kernel: pci: remove pci=firmware command line parameter handling

[Bjorn Helgaas]

On Mon, Feb 29, 2016 at 05:43:20PM +0000, Lorenzo Pieralisi wrote:
> According to kernel documentation, the pci=firmware command line
> parameter is only meant to be used on IXP2000 ARM platforms to prevent
> the kernel from assigning PCI resources configured by the bootloader.
> 
> Since the IXP2000 ARM platforms support has been removed from the
> kernel in commit:
> 
> commit c65f2abf54a6 ("ARM: remove ixp23xx and ixp2000 platforms")
> 
> its platforms specific kernel parameters should be removed
> too from the kernel documentation along with the kernel code
> currently handling them in that they have just become obsolete.
> 
> This patch removes the pci=firmware command line parameter handling
> from ARM code and the related kernel parameters documentation
> section.
> 
> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

Acked-by: Bjorn Helgaas <bhelgaas@google.com>

It looks like Rob merged c65f2abf54a6, so maybe he will merge this as
well?  Otherwise I'd be happy to merge it; just let me know if you
want me to.

> Cc: Arnd Bergmann <arnd@arndb.de>
> Cc: Lennert Buytenhek <kernel@wantstofly.org>
> Cc: Jonathan Corbet <corbet@lwn.net>
> Cc: Bjorn Helgaas <bhelgaas@google.com>
> Cc: Rob Herring <robh@kernel.org>
> Cc: Russell King <linux@arm.linux.org.uk>
> ---
>  Documentation/kernel-parameters.txt | 5 -----
>  arch/arm/kernel/bios32.c            | 3 ---
>  2 files changed, 8 deletions(-)
> 
> diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
> index 9a53c92..e213acc 100644
> --- a/Documentation/kernel-parameters.txt
> +++ b/Documentation/kernel-parameters.txt
> @@ -2875,11 +2875,6 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
>  				for broken drivers that don't call it.
>  		skip_isa_align	[X86] do not align io start addr, so can
>  				handle more pci cards
> -		firmware	[ARM] Do not re-enumerate the bus but instead
> -				just use the configuration from the
> -				bootloader. This is currently used on
> -				IXP2000 systems where the bus has to be
> -				configured a certain way for adjunct CPUs.
>  		noearly		[X86] Don't do any early type 1 scanning.
>  				This might help on some broken boards which
>  				machine check when some devices' config space
> diff --git a/arch/arm/kernel/bios32.c b/arch/arm/kernel/bios32.c
> index 066f7f9..05e61a2 100644
> --- a/arch/arm/kernel/bios32.c
> +++ b/arch/arm/kernel/bios32.c
> @@ -550,9 +550,6 @@ char * __init pcibios_setup(char *str)
>  	if (!strcmp(str, "debug")) {
>  		debug_pci = 1;
>  		return NULL;
> -	} else if (!strcmp(str, "firmware")) {
> -		pci_add_flags(PCI_PROBE_ONLY);
> -		return NULL;
>  	}
>  	return str;
>  }
> -- 
> 2.5.1
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-pci" in
> the body of a message to majordomo at vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

[RFC PATCH] arm: kernel: pci: remove pci=firmware command line parameter handling

[Lorenzo Pieralisi]

On Mon, Feb 29, 2016 at 04:56:53PM -0600, Bjorn Helgaas wrote:
> On Mon, Feb 29, 2016 at 05:43:20PM +0000, Lorenzo Pieralisi wrote:
> > According to kernel documentation, the pci=firmware command line
> > parameter is only meant to be used on IXP2000 ARM platforms to prevent
> > the kernel from assigning PCI resources configured by the bootloader.
> > 
> > Since the IXP2000 ARM platforms support has been removed from the
> > kernel in commit:
> > 
> > commit c65f2abf54a6 ("ARM: remove ixp23xx and ixp2000 platforms")
> > 
> > its platforms specific kernel parameters should be removed
> > too from the kernel documentation along with the kernel code
> > currently handling them in that they have just become obsolete.
> > 
> > This patch removes the pci=firmware command line parameter handling
> > from ARM code and the related kernel parameters documentation
> > section.
> > 
> > Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
> 
> Acked-by: Bjorn Helgaas <bhelgaas@google.com>

Thank you !

> It looks like Rob merged c65f2abf54a6, so maybe he will merge this as
> well?  Otherwise I'd be happy to merge it; just let me know if you
> want me to.

Hopefully the kernel parameter description matches current usage
on ARM systems, it could affect all ARM 32-bit platforms (if any ?) that
abused the pci=firmware parameter, it is just impossible for me to check
(that's why I posted it as an RFC. It would be very good to remove that
kernel parameter though).

Having said that, either way of merging it is fine by me, I can send it
to Russell's patch system too, given that there are already patches queued
to remove PCI_PROBE_ONLY from some PCI host controllers I am happy for it
to go via PCI tree.

Rob, Russell, any preferences ?

Thanks !
Lorenzo

> 
> > Cc: Arnd Bergmann <arnd@arndb.de>
> > Cc: Lennert Buytenhek <kernel@wantstofly.org>
> > Cc: Jonathan Corbet <corbet@lwn.net>
> > Cc: Bjorn Helgaas <bhelgaas@google.com>
> > Cc: Rob Herring <robh@kernel.org>
> > Cc: Russell King <linux@arm.linux.org.uk>
> > ---
> >  Documentation/kernel-parameters.txt | 5 -----
> >  arch/arm/kernel/bios32.c            | 3 ---
> >  2 files changed, 8 deletions(-)
> > 
> > diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
> > index 9a53c92..e213acc 100644
> > --- a/Documentation/kernel-parameters.txt
> > +++ b/Documentation/kernel-parameters.txt
> > @@ -2875,11 +2875,6 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
> >  				for broken drivers that don't call it.
> >  		skip_isa_align	[X86] do not align io start addr, so can
> >  				handle more pci cards
> > -		firmware	[ARM] Do not re-enumerate the bus but instead
> > -				just use the configuration from the
> > -				bootloader. This is currently used on
> > -				IXP2000 systems where the bus has to be
> > -				configured a certain way for adjunct CPUs.
> >  		noearly		[X86] Don't do any early type 1 scanning.
> >  				This might help on some broken boards which
> >  				machine check when some devices' config space
> > diff --git a/arch/arm/kernel/bios32.c b/arch/arm/kernel/bios32.c
> > index 066f7f9..05e61a2 100644
> > --- a/arch/arm/kernel/bios32.c
> > +++ b/arch/arm/kernel/bios32.c
> > @@ -550,9 +550,6 @@ char * __init pcibios_setup(char *str)
> >  	if (!strcmp(str, "debug")) {
> >  		debug_pci = 1;
> >  		return NULL;
> > -	} else if (!strcmp(str, "firmware")) {
> > -		pci_add_flags(PCI_PROBE_ONLY);
> > -		return NULL;
> >  	}
> >  	return str;
> >  }
> > -- 
> > 2.5.1
> > 
> > --
> > To unsubscribe from this list: send the line "unsubscribe linux-pci" in
> > the body of a message to majordomo at vger.kernel.org
> > More majordomo info at  http://vger.kernel.org/majordomo-info.html
>