diff mbox

[V4,1/3] ACPI, PCI, IRQ: assign ISA IRQ directly during early boot stages

Message ID 1476915664-27231-2-git-send-email-okaya@codeaurora.org
State Superseded
Headers show

Commit Message

Sinan Kaya Oct. 19, 2016, 10:21 p.m. UTC
The penalty determination of ISA IRQ goes through 4 paths.
1. assign PCI_USING during power up via acpi_irq_penalty_init.
2. update the penalty with acpi_penalize_isa_irq function based on the
active parameter.
3. kernel command line penalty update via acpi_irq_penalty_update function.
4. increment the penalty as USING right after the IRQ is assign to PCI.

acpi_penalize_isa_irq and acpi_irq_penalty_update functions get called
before the ACPI subsystem is started.

These API need to bypass the acpi_irq_get_penalty function.

Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
---
 drivers/acpi/pci_link.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Comments

Rafael J. Wysocki Oct. 20, 2016, 9:39 p.m. UTC | #1
On Thu, Oct 20, 2016 at 12:21 AM, Sinan Kaya <okaya@codeaurora.org> wrote:
> The penalty determination of ISA IRQ goes through 4 paths.
> 1. assign PCI_USING during power up via acpi_irq_penalty_init.
> 2. update the penalty with acpi_penalize_isa_irq function based on the
> active parameter.
> 3. kernel command line penalty update via acpi_irq_penalty_update function.
> 4. increment the penalty as USING right after the IRQ is assign to PCI.
>
> acpi_penalize_isa_irq and acpi_irq_penalty_update functions get called
> before the ACPI subsystem is started.
>
> These API need to bypass the acpi_irq_get_penalty function.
>
> Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
> ---
>  drivers/acpi/pci_link.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/acpi/pci_link.c b/drivers/acpi/pci_link.c
> index c983bf7..4f37938 100644
> --- a/drivers/acpi/pci_link.c
> +++ b/drivers/acpi/pci_link.c
> @@ -849,7 +849,7 @@ static int __init acpi_irq_penalty_update(char *str, int used)
>                         continue;
>
>                 if (used)
> -                       new_penalty = acpi_irq_get_penalty(irq) +
> +                       new_penalty = acpi_isa_irq_penalty[irq] +
>                                         PIRQ_PENALTY_ISA_USED;
>                 else
>                         new_penalty = 0;
> @@ -871,7 +871,7 @@ static int __init acpi_irq_penalty_update(char *str, int used)
>  void acpi_penalize_isa_irq(int irq, int active)
>  {
>         if ((irq >= 0) && (irq < ARRAY_SIZE(acpi_isa_irq_penalty)))
> -               acpi_isa_irq_penalty[irq] = acpi_irq_get_penalty(irq) +
> +               acpi_isa_irq_penalty[irq] = acpi_isa_irq_penalty[irq] +

This looks slightly odd.  What about

+               acpi_isa_irq_penalty[irq] +=

>                   (active ? PIRQ_PENALTY_ISA_USED : PIRQ_PENALTY_PCI_USING);
>  }
>

Thanks,
Rafael
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Bjorn Helgaas Oct. 21, 2016, 1:39 a.m. UTC | #2
On Wed, Oct 19, 2016 at 06:21:02PM -0400, Sinan Kaya wrote:
> The penalty determination of ISA IRQ goes through 4 paths.
> 1. assign PCI_USING during power up via acpi_irq_penalty_init.
> 2. update the penalty with acpi_penalize_isa_irq function based on the
> active parameter.
> 3. kernel command line penalty update via acpi_irq_penalty_update function.
> 4. increment the penalty as USING right after the IRQ is assign to PCI.
> 
> acpi_penalize_isa_irq and acpi_irq_penalty_update functions get called
> before the ACPI subsystem is started.
> 
> These API need to bypass the acpi_irq_get_penalty function.

I don't mind this patch, but the changelog doesn't tell me what's
broken and why we need this fix.  Apparently acpi_irq_get_penalty()
doesn't work before ACPI is initialized, but I don't see *why* it
wouldn't work.

However, I see one bug it *does* fix: we do not store the SCI penalty
in the acpi_isa_irq_penalty[] table because acpi_isa_irq_penalty[]
only holds ISA IRQ penalties, and there's no guarantee that the SCI is
an ISA IRQ.  But prior to this patch, we added in the SCI penalty to
the acpi_isa_irq_penalty[] entry when the SCI was an ISA IRQ, which
makes acpi_irq_get_penalty() return the wrong thing.  Consider:

  Initially     acpi_isa_irq_penalty[9] = 0.
  Assume        sci_interrupt = 9.
  Then          acpi_irq_get_penalty(9) returns X.
  If we call    acpi_penalize_isa_irq(9, 1),
  it sets       acpi_isa_irq_penalty[9] = X,
  and now       acpi_irq_get_penalty(9) returns X + X.

I'd propose a changelog like this:

  We do not want to store the SCI penalty in the acpi_isa_irq_penalty[]
  table because acpi_isa_irq_penalty[] only holds ISA IRQ penalties and
  there's no guarantee that the SCI is an ISA IRQ.  We add in the SCI
  penalty as a special case in acpi_irq_get_penalty().

  But if we called acpi_penalize_isa_irq() or acpi_irq_penalty_update()
  for an SCI that happened to be an ISA IRQ, they stored the SCI
  penalty (part of the acpi_irq_get_penalty() return value) in
  acpi_isa_irq_penalty[].  Subsequent calls to acpi_irq_get_penalty()
  returned a penalty that included *two* SCI penalties.

If this actually fixes a worse problem related to ACPI initialization,
of course you should detail that.

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

> Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
> ---
>  drivers/acpi/pci_link.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/acpi/pci_link.c b/drivers/acpi/pci_link.c
> index c983bf7..4f37938 100644
> --- a/drivers/acpi/pci_link.c
> +++ b/drivers/acpi/pci_link.c
> @@ -849,7 +849,7 @@ static int __init acpi_irq_penalty_update(char *str, int used)
>  			continue;
>  
>  		if (used)
> -			new_penalty = acpi_irq_get_penalty(irq) +
> +			new_penalty = acpi_isa_irq_penalty[irq] +
>  					PIRQ_PENALTY_ISA_USED;
>  		else
>  			new_penalty = 0;
> @@ -871,7 +871,7 @@ static int __init acpi_irq_penalty_update(char *str, int used)
>  void acpi_penalize_isa_irq(int irq, int active)
>  {
>  	if ((irq >= 0) && (irq < ARRAY_SIZE(acpi_isa_irq_penalty)))
> -		acpi_isa_irq_penalty[irq] = acpi_irq_get_penalty(irq) +
> +		acpi_isa_irq_penalty[irq] = acpi_isa_irq_penalty[irq] +
>  		  (active ? PIRQ_PENALTY_ISA_USED : PIRQ_PENALTY_PCI_USING);
>  }
>  
> -- 
> 1.9.1
> 
> 
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
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Bjorn Helgaas Oct. 21, 2016, 2:07 p.m. UTC | #3
On Thu, Oct 20, 2016 at 08:39:30PM -0500, Bjorn Helgaas wrote:
> On Wed, Oct 19, 2016 at 06:21:02PM -0400, Sinan Kaya wrote:
> > The penalty determination of ISA IRQ goes through 4 paths.
> > 1. assign PCI_USING during power up via acpi_irq_penalty_init.
> > 2. update the penalty with acpi_penalize_isa_irq function based on the
> > active parameter.
> > 3. kernel command line penalty update via acpi_irq_penalty_update function.
> > 4. increment the penalty as USING right after the IRQ is assign to PCI.
> > 
> > acpi_penalize_isa_irq and acpi_irq_penalty_update functions get called
> > before the ACPI subsystem is started.
> > 
> > These API need to bypass the acpi_irq_get_penalty function.
> 
> I don't mind this patch, but the changelog doesn't tell me what's
> broken and why we need this fix.  Apparently acpi_irq_get_penalty()
> doesn't work before ACPI is initialized, but I don't see *why* it
> wouldn't work.
> 
> However, I see one bug it *does* fix: we do not store the SCI penalty
> in the acpi_isa_irq_penalty[] table because acpi_isa_irq_penalty[]
> only holds ISA IRQ penalties, and there's no guarantee that the SCI is
> an ISA IRQ.  But prior to this patch, we added in the SCI penalty to
> the acpi_isa_irq_penalty[] entry when the SCI was an ISA IRQ, which
> makes acpi_irq_get_penalty() return the wrong thing.  Consider:
> 
>   Initially     acpi_isa_irq_penalty[9] = 0.
>   Assume        sci_interrupt = 9.
>   Then          acpi_irq_get_penalty(9) returns X.
>   If we call    acpi_penalize_isa_irq(9, 1),
>   it sets       acpi_isa_irq_penalty[9] = X,
>   and now       acpi_irq_get_penalty(9) returns X + X.

Oops, I forgot the penalty we *intended* to add with
acpi_penalize_isa_irq().  It's really like this, where X is the SCI
penalty and Y is the part added by acpi_penalize_isa_irq():

  Initially     acpi_isa_irq_penalty[9] = 0.
  Assume        sci_interrupt = 9.
  Then          acpi_irq_get_penalty(9) returns X.
  If we call    acpi_penalize_isa_irq(9, 1),
  it sets       acpi_isa_irq_penalty[9] = X + Y,
  and now       acpi_irq_get_penalty(9) returns X + X + Y.

At the end, acpi_irq_get_penalty(9) *should* return X + Y, but instead
it returns X + X + Y, i.e., the SCI penalty is included twice.
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Jonathan Liu Oct. 23, 2016, 3:48 a.m. UTC | #4
On 20 October 2016 at 09:21, Sinan Kaya <okaya@codeaurora.org> wrote:
> The penalty determination of ISA IRQ goes through 4 paths.
> 1. assign PCI_USING during power up via acpi_irq_penalty_init.
> 2. update the penalty with acpi_penalize_isa_irq function based on the
> active parameter.
> 3. kernel command line penalty update via acpi_irq_penalty_update function.
> 4. increment the penalty as USING right after the IRQ is assign to PCI.
>
> acpi_penalize_isa_irq and acpi_irq_penalty_update functions get called
> before the ACPI subsystem is started.
>
> These API need to bypass the acpi_irq_get_penalty function.
>
> Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
> ---
>  drivers/acpi/pci_link.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/acpi/pci_link.c b/drivers/acpi/pci_link.c
> index c983bf7..4f37938 100644
> --- a/drivers/acpi/pci_link.c
> +++ b/drivers/acpi/pci_link.c
> @@ -849,7 +849,7 @@ static int __init acpi_irq_penalty_update(char *str, int used)
>                         continue;
>
>                 if (used)
> -                       new_penalty = acpi_irq_get_penalty(irq) +
> +                       new_penalty = acpi_isa_irq_penalty[irq] +
>                                         PIRQ_PENALTY_ISA_USED;
>                 else
>                         new_penalty = 0;
> @@ -871,7 +871,7 @@ static int __init acpi_irq_penalty_update(char *str, int used)
>  void acpi_penalize_isa_irq(int irq, int active)
>  {
>         if ((irq >= 0) && (irq < ARRAY_SIZE(acpi_isa_irq_penalty)))
> -               acpi_isa_irq_penalty[irq] = acpi_irq_get_penalty(irq) +
> +               acpi_isa_irq_penalty[irq] = acpi_isa_irq_penalty[irq] +
>                   (active ? PIRQ_PENALTY_ISA_USED : PIRQ_PENALTY_PCI_USING);
>  }
>

This series fixes one or more network adapters not working in Linux
32-bit x86 guest running inside VirtualBox if I have 4 network
adapters enabled. The following message no longer appears in the
kernel log:
ACPI: No IRQ available for PCI Interrupt Link [LNKD]. Try pci=noacpi or acpi=off

Tested-by: Jonathan Liu <net147@gmail.com>
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Sinan Kaya Oct. 24, 2016, 3:22 a.m. UTC | #5
On 10/20/2016 9:39 PM, Bjorn Helgaas wrote:
>> These API need to bypass the acpi_irq_get_penalty function.
> I don't mind this patch, but the changelog doesn't tell me what's
> broken and why we need this fix.  Apparently acpi_irq_get_penalty()
> doesn't work before ACPI is initialized, but I don't see *why* it
> wouldn't work.

I'll update the commit message as you suggested. The code doesn't work
if we apply PATCH V4 2/3 + PATCH V4 3/3 without PATCH V4 1/3 since
the caller is going to end up calling get_penalty function while ACPI
is not initialized. This happened during the debug of this regression.
Sinan Kaya Oct. 24, 2016, 3:48 a.m. UTC | #6
On 10/20/2016 5:39 PM, Rafael J. Wysocki wrote:
>> @@ -871,7 +871,7 @@ static int __init acpi_irq_penalty_update(char *str, int used)
>> >  void acpi_penalize_isa_irq(int irq, int active)
>> >  {
>> >         if ((irq >= 0) && (irq < ARRAY_SIZE(acpi_isa_irq_penalty)))
>> > -               acpi_isa_irq_penalty[irq] = acpi_irq_get_penalty(irq) +
>> > +               acpi_isa_irq_penalty[irq] = acpi_isa_irq_penalty[irq] +
> This looks slightly odd.  What about
> 
> +               acpi_isa_irq_penalty[irq] +=
> 
>> >                   (active ? PIRQ_PENALTY_ISA_USED : PIRQ_PENALTY_PCI_USING);
>> >  }

Makes sense.
Sinan Kaya Oct. 24, 2016, 4:17 a.m. UTC | #7
Thanks,

On 10/22/2016 11:48 PM, Jonathan Liu wrote:
> This series fixes one or more network adapters not working in Linux
> 32-bit x86 guest running inside VirtualBox if I have 4 network
> adapters enabled. The following message no longer appears in the
> kernel log:
> ACPI: No IRQ available for PCI Interrupt Link [LNKD]. Try pci=noacpi or acpi=off
> 
> Tested-by: Jonathan Liu <net147@gmail.com>

I'm hoping that you can retest V5 so that Rafael can pull in your tested-by into
the commit message.
Jonathan Liu Oct. 24, 2016, 4:21 a.m. UTC | #8
On 24 October 2016 at 15:17, Sinan Kaya <okaya@codeaurora.org> wrote:
> Thanks,
>
> On 10/22/2016 11:48 PM, Jonathan Liu wrote:
>> This series fixes one or more network adapters not working in Linux
>> 32-bit x86 guest running inside VirtualBox if I have 4 network
>> adapters enabled. The following message no longer appears in the
>> kernel log:
>> ACPI: No IRQ available for PCI Interrupt Link [LNKD]. Try pci=noacpi or acpi=off
>>
>> Tested-by: Jonathan Liu <net147@gmail.com>
>
> I'm hoping that you can retest V5 so that Rafael can pull in your tested-by into
> the commit message.
>
> --
> Sinan Kaya
> Qualcomm Datacenter Technologies, Inc. as an affiliate of Qualcomm Technologies, Inc.
> Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project.

Sure. Please CC me when you submit V5.

Regards,
Jonathan
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diff mbox

Patch

diff --git a/drivers/acpi/pci_link.c b/drivers/acpi/pci_link.c
index c983bf7..4f37938 100644
--- a/drivers/acpi/pci_link.c
+++ b/drivers/acpi/pci_link.c
@@ -849,7 +849,7 @@  static int __init acpi_irq_penalty_update(char *str, int used)
 			continue;
 
 		if (used)
-			new_penalty = acpi_irq_get_penalty(irq) +
+			new_penalty = acpi_isa_irq_penalty[irq] +
 					PIRQ_PENALTY_ISA_USED;
 		else
 			new_penalty = 0;
@@ -871,7 +871,7 @@  static int __init acpi_irq_penalty_update(char *str, int used)
 void acpi_penalize_isa_irq(int irq, int active)
 {
 	if ((irq >= 0) && (irq < ARRAY_SIZE(acpi_isa_irq_penalty)))
-		acpi_isa_irq_penalty[irq] = acpi_irq_get_penalty(irq) +
+		acpi_isa_irq_penalty[irq] = acpi_isa_irq_penalty[irq] +
 		  (active ? PIRQ_PENALTY_ISA_USED : PIRQ_PENALTY_PCI_USING);
 }