[PATCH v2] Disable MSI also when pcie-octeon.pcie_disable on

[PATCH v2] Disable MSI also when pcie-octeon.pcie_disable on

[YunQiang Su]

From: YunQiang Su <ysu@wavecomp.com>

Octeon has an boot-time option to disable pcie.

Since MSI depends on PCI-E, we should also disable MSI also with
this options is on.

Signed-off-by: YunQiang Su <ysu@wavecomp.com>
---
 arch/mips/pci/msi-octeon.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/mips/pci/msi-octeon.c b/arch/mips/pci/msi-octeon.c
index 2a5bb849b..288b58b00 100644
--- a/arch/mips/pci/msi-octeon.c
+++ b/arch/mips/pci/msi-octeon.c
@@ -369,7 +369,9 @@ int __init octeon_msi_initialize(void)
 	int irq;
 	struct irq_chip *msi;
 
-	if (octeon_dma_bar_type == OCTEON_DMA_BAR_TYPE_PCIE) {
+	if (octeon_dma_bar_type == OCTEON_DMA_BAR_TYPE_INVALID) {
+		return 0;
+	} else if (octeon_dma_bar_type == OCTEON_DMA_BAR_TYPE_PCIE) {
 		msi_rcv_reg[0] = CVMX_PEXP_NPEI_MSI_RCV0;
 		msi_rcv_reg[1] = CVMX_PEXP_NPEI_MSI_RCV1;
 		msi_rcv_reg[2] = CVMX_PEXP_NPEI_MSI_RCV2;
-- 
2.20.1

Re: [PATCH v2] Disable MSI also when pcie-octeon.pcie_disable on

[YunQiang Su]

YunQiang Su <syq@debian.org> 于2019年1月8日周二 下午1:45写道：
>
> From: YunQiang Su <ysu@wavecomp.com>
>
> Octeon has an boot-time option to disable pcie.
>
> Since MSI depends on PCI-E, we should also disable MSI also with
> this options is on.
>
> Signed-off-by: YunQiang Su <ysu@wavecomp.com>
> ---
>  arch/mips/pci/msi-octeon.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/arch/mips/pci/msi-octeon.c b/arch/mips/pci/msi-octeon.c
> index 2a5bb849b..288b58b00 100644
> --- a/arch/mips/pci/msi-octeon.c
> +++ b/arch/mips/pci/msi-octeon.c
> @@ -369,7 +369,9 @@ int __init octeon_msi_initialize(void)
>         int irq;
>         struct irq_chip *msi;
>
> -       if (octeon_dma_bar_type == OCTEON_DMA_BAR_TYPE_PCIE) {
> +       if (octeon_dma_bar_type == OCTEON_DMA_BAR_TYPE_INVALID) {
> +               return 0;
> +       } else if (octeon_dma_bar_type == OCTEON_DMA_BAR_TYPE_PCIE) {

This code snip appears when 2.6.36, and this boot time option first
appears when 3.3.
So, when backport, it make sense for 3.3+.

>                 msi_rcv_reg[0] = CVMX_PEXP_NPEI_MSI_RCV0;
>                 msi_rcv_reg[1] = CVMX_PEXP_NPEI_MSI_RCV1;
>                 msi_rcv_reg[2] = CVMX_PEXP_NPEI_MSI_RCV2;
> --
> 2.20.1
>

Re: [PATCH v2] Disable MSI also when pcie-octeon.pcie_disable on

[Paul Burton]

Hi YunQiang,

On Tue, Jan 08, 2019 at 01:45:10PM +0800, YunQiang Su wrote:
> From: YunQiang Su <ysu@wavecomp.com>
> 
> Octeon has an boot-time option to disable pcie.
> 
> Since MSI depends on PCI-E, we should also disable MSI also with
> this options is on.

Does this fix a bug you're seeing? Or is it just intended to avoid
redundant work?

If it fixes a bug then I'll apply it to mips-fixes & copy stable,
otherwise I'll apply it to mips-next & not copy stable.

Thanks,
    Paul

> Signed-off-by: YunQiang Su <ysu@wavecomp.com>
> ---
>  arch/mips/pci/msi-octeon.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/mips/pci/msi-octeon.c b/arch/mips/pci/msi-octeon.c
> index 2a5bb849b..288b58b00 100644
> --- a/arch/mips/pci/msi-octeon.c
> +++ b/arch/mips/pci/msi-octeon.c
> @@ -369,7 +369,9 @@ int __init octeon_msi_initialize(void)
>  	int irq;
>  	struct irq_chip *msi;
>  
> -	if (octeon_dma_bar_type == OCTEON_DMA_BAR_TYPE_PCIE) {
> +	if (octeon_dma_bar_type == OCTEON_DMA_BAR_TYPE_INVALID) {
> +		return 0;
> +	} else if (octeon_dma_bar_type == OCTEON_DMA_BAR_TYPE_PCIE) {
>  		msi_rcv_reg[0] = CVMX_PEXP_NPEI_MSI_RCV0;
>  		msi_rcv_reg[1] = CVMX_PEXP_NPEI_MSI_RCV1;
>  		msi_rcv_reg[2] = CVMX_PEXP_NPEI_MSI_RCV2;
> -- 
> 2.20.1
> 

Re: [PATCH v2] Disable MSI also when pcie-octeon.pcie_disable on

[Yunqiang Su]

> 在 2019年1月11日，上午2:24，Paul Burton <pburton@wavecomp.com> 写道：
> 
> Hi YunQiang,
> 
> On Tue, Jan 08, 2019 at 01:45:10PM +0800, YunQiang Su wrote:
>> From: YunQiang Su <ysu@wavecomp.com>
>> 
>> Octeon has an boot-time option to disable pcie.
>> 
>> Since MSI depends on PCI-E, we should also disable MSI also with
>> this options is on.
> 
> Does this fix a bug you're seeing? Or is it just intended to avoid
> redundant work?
> 

I have no idea whether this is a bug or new feathers.
I get an Cavium machine, which has no PCI at all, and so I have to disable the PCI totally.

For me there are 2 ways: disable on build-time or disable on runtime.
Since Debian prefer to use a single kernel image.
So I need to disable it on runtime.

> If it fixes a bug then I'll apply it to mips-fixes & copy stable,
> otherwise I'll apply it to mips-next & not copy stable.
> 

I prefer it to be backported.

> Thanks,
>    Paul
> 
>> Signed-off-by: YunQiang Su <ysu@wavecomp.com>
>> ---
>> arch/mips/pci/msi-octeon.c | 4 +++-
>> 1 file changed, 3 insertions(+), 1 deletion(-)
>> 
>> diff --git a/arch/mips/pci/msi-octeon.c b/arch/mips/pci/msi-octeon.c
>> index 2a5bb849b..288b58b00 100644
>> --- a/arch/mips/pci/msi-octeon.c
>> +++ b/arch/mips/pci/msi-octeon.c
>> @@ -369,7 +369,9 @@ int __init octeon_msi_initialize(void)
>> 	int irq;
>> 	struct irq_chip *msi;
>> 
>> -	if (octeon_dma_bar_type == OCTEON_DMA_BAR_TYPE_PCIE) {
>> +	if (octeon_dma_bar_type == OCTEON_DMA_BAR_TYPE_INVALID) {
>> +		return 0;
>> +	} else if (octeon_dma_bar_type == OCTEON_DMA_BAR_TYPE_PCIE) {
>> 		msi_rcv_reg[0] = CVMX_PEXP_NPEI_MSI_RCV0;
>> 		msi_rcv_reg[1] = CVMX_PEXP_NPEI_MSI_RCV1;
>> 		msi_rcv_reg[2] = CVMX_PEXP_NPEI_MSI_RCV2;
>> -- 
>> 2.20.1
>> 

Re: [PATCH v2] Disable MSI also when pcie-octeon.pcie_disable on

[Paul Burton]

Hi Yunqiang,

On Thu, Jan 10, 2019 at 10:35:13AM -0800, Yunqiang Su wrote:
> > 在 2019年1月11日，上午2:24，Paul Burton <pburton@wavecomp.com> 写道：
> > Hi YunQiang,
> > 
> > On Tue, Jan 08, 2019 at 01:45:10PM +0800, YunQiang Su wrote:
> >> From: YunQiang Su <ysu@wavecomp.com>
> >> 
> >> Octeon has an boot-time option to disable pcie.
> >> 
> >> Since MSI depends on PCI-E, we should also disable MSI also with
> >> this options is on.
> > 
> > Does this fix a bug you're seeing? Or is it just intended to avoid
> > redundant work?
> 
> I have no idea whether this is a bug or new feathers.
> I get an Cavium machine, which has no PCI at all, and so I have to disable the PCI totally.
> 
> For me there are 2 ways: disable on build-time or disable on runtime.
> Since Debian prefer to use a single kernel image.
> So I need to disable it on runtime.

Let me phrase this another way - if you boot with PCIe disabled, but
without your patch applied, what happens? Does the system work or does
it break?

You must have written the patch for a reason, I just want to know what
that reason is.

> > If it fixes a bug then I'll apply it to mips-fixes & copy stable,
> > otherwise I'll apply it to mips-next & not copy stable.
> 
> I prefer it to be backported.

Only if it fixes a bug.

Thanks,
    Paul

Re: [PATCH v2] Disable MSI also when pcie-octeon.pcie_disable on

[YunQiang Su]

Paul Burton <paul.burton@mips.com> 于2019年1月11日周五 上午2:45写道：
>
> Hi Yunqiang,
>
> On Thu, Jan 10, 2019 at 10:35:13AM -0800, Yunqiang Su wrote:
> > > 在 2019年1月11日，上午2:24，Paul Burton <pburton@wavecomp.com> 写道：
> > > Hi YunQiang,
> > >
> > > On Tue, Jan 08, 2019 at 01:45:10PM +0800, YunQiang Su wrote:
> > >> From: YunQiang Su <ysu@wavecomp.com>
> > >>
> > >> Octeon has an boot-time option to disable pcie.
> > >>
> > >> Since MSI depends on PCI-E, we should also disable MSI also with
> > >> this options is on.
> > >
> > > Does this fix a bug you're seeing? Or is it just intended to avoid
> > > redundant work?
> >
> > I have no idea whether this is a bug or new feathers.
> > I get an Cavium machine, which has no PCI at all, and so I have to disable the PCI totally.
> >
> > For me there are 2 ways: disable on build-time or disable on runtime.
> > Since Debian prefer to use a single kernel image.
> > So I need to disable it on runtime.
>
> Let me phrase this another way - if you boot with PCIe disabled, but
> without your patch applied, what happens? Does the system work or does
> it break?
>
Yes. I think it is another bug.
https://lore.kernel.org/linux-mips/CAKcpw6Uf=_f4T1ZBLnp9gWrp1rjwuLfpF0h865-U4BOpuFLiiw@mail.gmail.com/T/#t

> You must have written the patch for a reason, I just want to know what
> that reason is.
>
> > > If it fixes a bug then I'll apply it to mips-fixes & copy stable,
> > > otherwise I'll apply it to mips-next & not copy stable.
> >
> > I prefer it to be backported.
>
> Only if it fixes a bug.
>
> Thanks,
>     Paul

Re: [PATCH v2] Disable MSI also when pcie-octeon.pcie_disable on

[YunQiang Su]

Paul Burton <paul.burton@mips.com> 于2019年1月11日周五 上午2:45写道：
>
> Hi Yunqiang,
>
> On Thu, Jan 10, 2019 at 10:35:13AM -0800, Yunqiang Su wrote:
> > > 在 2019年1月11日，上午2:24，Paul Burton <pburton@wavecomp.com> 写道：
> > > Hi YunQiang,
> > >
> > > On Tue, Jan 08, 2019 at 01:45:10PM +0800, YunQiang Su wrote:
> > >> From: YunQiang Su <ysu@wavecomp.com>
> > >>
> > >> Octeon has an boot-time option to disable pcie.
> > >>
> > >> Since MSI depends on PCI-E, we should also disable MSI also with
> > >> this options is on.
> > >
> > > Does this fix a bug you're seeing? Or is it just intended to avoid
> > > redundant work?
> >
> > I have no idea whether this is a bug or new feathers.
> > I get an Cavium machine, which has no PCI at all, and so I have to disable the PCI totally.
> >
> > For me there are 2 ways: disable on build-time or disable on runtime.
> > Since Debian prefer to use a single kernel image.
> > So I need to disable it on runtime.
>
> Let me phrase this another way - if you boot with PCIe disabled, but
> without your patch applied, what happens? Does the system work or does
> it break?

With pcie disabled pcie with pcie-octeon.pcie_disable, and without this patch,
the kernel will fail to boot very early.

On https://elixir.bootlin.com/linux/latest/source/arch/mips/pci/msi-octeon.c#L399
request_irq

>
> You must have written the patch for a reason, I just want to know what
> that reason is.
>
> > > If it fixes a bug then I'll apply it to mips-fixes & copy stable,
> > > otherwise I'll apply it to mips-next & not copy stable.
> >
> > I prefer it to be backported.
>
> Only if it fixes a bug.
>
> Thanks,
>     Paul

Re: [PATCH v2] Disable MSI also when pcie-octeon.pcie_disable on

[Paul Burton]

Hello,

YunQiang Su wrote:
> From: YunQiang Su <ysu@wavecomp.com>
> 
> Octeon has an boot-time option to disable pcie.
> 
> Since MSI depends on PCI-E, we should also disable MSI also with
> this options is on.
> 
> Signed-off-by: YunQiang Su <ysu@wavecomp.com>

Applied to mips-fixes.

Thanks,
    Paul

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