2018-01-11 15:03:57

by Yazen Ghannam

[permalink] [raw]
Subject: [PATCH] PCI/ACPI: Disable AER when _OSC control bit is clear.

From: Yazen Ghannam <[email protected]>

Currently, aer_service_init() checks if AER is available and that
Firmware First handling is not enabled. The _OSC request for AER is
not taken into account when deciding to enable AER in Linux.

We should check that the _OSC control for AER is set. If it's not
then AER should be disabled.

The _OSC control for AER is not requested when APEI Firmware First is
used, so the same condition applies.

Mark AER as disabled if the _OSC request was not made or accepted.

Remove redunant check for aer_acpi_firmware_first() when calling
aer_service_init(), since this is check is already included when
checking the _OSC control.

Signed-off-by: Yazen Ghannam <[email protected]>
---
drivers/acpi/pci_root.c | 3 +++
drivers/pci/pcie/aer/aerdrv.c | 2 +-
2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
index 6fc204a52493..19a625ed8de9 100644
--- a/drivers/acpi/pci_root.c
+++ b/drivers/acpi/pci_root.c
@@ -512,6 +512,9 @@ static void negotiate_os_control(struct acpi_pci_root *root, int *no_aspm)
*/
*no_aspm = 1;
}
+
+ if (!(requested & control & OSC_PCI_EXPRESS_AER_CONTROL))
+ pci_no_aer();
}

static int acpi_pci_root_add(struct acpi_device *device,
diff --git a/drivers/pci/pcie/aer/aerdrv.c b/drivers/pci/pcie/aer/aerdrv.c
index 6ff5f5b4f5e6..39bb059777d0 100644
--- a/drivers/pci/pcie/aer/aerdrv.c
+++ b/drivers/pci/pcie/aer/aerdrv.c
@@ -374,7 +374,7 @@ static void aer_error_resume(struct pci_dev *dev)
*/
static int __init aer_service_init(void)
{
- if (!pci_aer_available() || aer_acpi_firmware_first())
+ if (!pci_aer_available())
return -ENXIO;
return pcie_port_service_register(&aerdriver);
}
--
2.14.1


2018-01-11 17:38:39

by Rafael J. Wysocki

[permalink] [raw]
Subject: Re: [PATCH] PCI/ACPI: Disable AER when _OSC control bit is clear.

On Thu, Jan 11, 2018 at 4:03 PM, Yazen Ghannam <[email protected]> wrote:
> From: Yazen Ghannam <[email protected]>
>
> Currently, aer_service_init() checks if AER is available and that
> Firmware First handling is not enabled. The _OSC request for AER is
> not taken into account when deciding to enable AER in Linux.
>
> We should check that the _OSC control for AER is set. If it's not
> then AER should be disabled.
>
> The _OSC control for AER is not requested when APEI Firmware First is
> used, so the same condition applies.
>
> Mark AER as disabled if the _OSC request was not made or accepted.
>
> Remove redunant check for aer_acpi_firmware_first() when calling
> aer_service_init(), since this is check is already included when
> checking the _OSC control.
>
> Signed-off-by: Yazen Ghannam <[email protected]>
> ---
> drivers/acpi/pci_root.c | 3 +++
> drivers/pci/pcie/aer/aerdrv.c | 2 +-
> 2 files changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
> index 6fc204a52493..19a625ed8de9 100644
> --- a/drivers/acpi/pci_root.c
> +++ b/drivers/acpi/pci_root.c
> @@ -512,6 +512,9 @@ static void negotiate_os_control(struct acpi_pci_root *root, int *no_aspm)
> */
> *no_aspm = 1;
> }
> +
> + if (!(requested & control & OSC_PCI_EXPRESS_AER_CONTROL))

One of the operators above needs to be a && I suppose?

> + pci_no_aer();
> }
>
> static int acpi_pci_root_add(struct acpi_device *device,
> diff --git a/drivers/pci/pcie/aer/aerdrv.c b/drivers/pci/pcie/aer/aerdrv.c
> index 6ff5f5b4f5e6..39bb059777d0 100644
> --- a/drivers/pci/pcie/aer/aerdrv.c
> +++ b/drivers/pci/pcie/aer/aerdrv.c
> @@ -374,7 +374,7 @@ static void aer_error_resume(struct pci_dev *dev)
> */
> static int __init aer_service_init(void)
> {
> - if (!pci_aer_available() || aer_acpi_firmware_first())
> + if (!pci_aer_available())
> return -ENXIO;
> return pcie_port_service_register(&aerdriver);
> }
> --

2018-01-11 17:48:25

by Yazen Ghannam

[permalink] [raw]
Subject: RE: [PATCH] PCI/ACPI: Disable AER when _OSC control bit is clear.

> -----Original Message-----
> From: [email protected] [mailto:[email protected]] On Behalf Of
> Rafael J. Wysocki
> Sent: Thursday, January 11, 2018 12:39 PM
> To: Ghannam, Yazen <[email protected]>
> Cc: ACPI Devel Maling List <[email protected]>; Linux Kernel Mailing
> List <[email protected]>; Linux PCI <[email protected]>;
> Rafael J. Wysocki <[email protected]>; Len Brown <[email protected]>; Bjorn
> Helgaas <[email protected]>; Borislav Petkov <[email protected]>
> Subject: Re: [PATCH] PCI/ACPI: Disable AER when _OSC control bit is clear.
>
> On Thu, Jan 11, 2018 at 4:03 PM, Yazen Ghannam
> <[email protected]> wrote:
> > From: Yazen Ghannam <[email protected]>
> >
> > Currently, aer_service_init() checks if AER is available and that
> > Firmware First handling is not enabled. The _OSC request for AER is
> > not taken into account when deciding to enable AER in Linux.
> >
> > We should check that the _OSC control for AER is set. If it's not
> > then AER should be disabled.
> >
> > The _OSC control for AER is not requested when APEI Firmware First is
> > used, so the same condition applies.
> >
> > Mark AER as disabled if the _OSC request was not made or accepted.
> >
> > Remove redunant check for aer_acpi_firmware_first() when calling
> > aer_service_init(), since this is check is already included when
> > checking the _OSC control.
> >
> > Signed-off-by: Yazen Ghannam <[email protected]>
> > ---
> > drivers/acpi/pci_root.c | 3 +++
> > drivers/pci/pcie/aer/aerdrv.c | 2 +-
> > 2 files changed, 4 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
> > index 6fc204a52493..19a625ed8de9 100644
> > --- a/drivers/acpi/pci_root.c
> > +++ b/drivers/acpi/pci_root.c
> > @@ -512,6 +512,9 @@ static void negotiate_os_control(struct
> acpi_pci_root *root, int *no_aspm)
> > */
> > *no_aspm = 1;
> > }
> > +
> > + if (!(requested & control & OSC_PCI_EXPRESS_AER_CONTROL))
>
> One of the operators above needs to be a && I suppose?
>

It's a 3-way bitwise AND to check that OSC_PCI_EXPRESS_AER_CONTROL is
set in both "requested" and "control".

IOW, we check if AER was requested by the OS and that the platform
granted the request.

Thanks,
Yazen

2018-01-11 18:03:27

by Rafael J. Wysocki

[permalink] [raw]
Subject: Re: [PATCH] PCI/ACPI: Disable AER when _OSC control bit is clear.

On Thu, Jan 11, 2018 at 6:48 PM, Ghannam, Yazen <[email protected]> wrote:
>> -----Original Message-----
>> From: [email protected] [mailto:[email protected]] On Behalf Of
>> Rafael J. Wysocki
>> Sent: Thursday, January 11, 2018 12:39 PM
>> To: Ghannam, Yazen <[email protected]>
>> Cc: ACPI Devel Maling List <[email protected]>; Linux Kernel Mailing
>> List <[email protected]>; Linux PCI <[email protected]>;
>> Rafael J. Wysocki <[email protected]>; Len Brown <[email protected]>; Bjorn
>> Helgaas <[email protected]>; Borislav Petkov <[email protected]>
>> Subject: Re: [PATCH] PCI/ACPI: Disable AER when _OSC control bit is clear.
>>
>> On Thu, Jan 11, 2018 at 4:03 PM, Yazen Ghannam
>> <[email protected]> wrote:
>> > From: Yazen Ghannam <[email protected]>
>> >
>> > Currently, aer_service_init() checks if AER is available and that
>> > Firmware First handling is not enabled. The _OSC request for AER is
>> > not taken into account when deciding to enable AER in Linux.
>> >
>> > We should check that the _OSC control for AER is set. If it's not
>> > then AER should be disabled.
>> >
>> > The _OSC control for AER is not requested when APEI Firmware First is
>> > used, so the same condition applies.
>> >
>> > Mark AER as disabled if the _OSC request was not made or accepted.
>> >
>> > Remove redunant check for aer_acpi_firmware_first() when calling
>> > aer_service_init(), since this is check is already included when
>> > checking the _OSC control.
>> >
>> > Signed-off-by: Yazen Ghannam <[email protected]>
>> > ---
>> > drivers/acpi/pci_root.c | 3 +++
>> > drivers/pci/pcie/aer/aerdrv.c | 2 +-
>> > 2 files changed, 4 insertions(+), 1 deletion(-)
>> >
>> > diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
>> > index 6fc204a52493..19a625ed8de9 100644
>> > --- a/drivers/acpi/pci_root.c
>> > +++ b/drivers/acpi/pci_root.c
>> > @@ -512,6 +512,9 @@ static void negotiate_os_control(struct
>> acpi_pci_root *root, int *no_aspm)
>> > */
>> > *no_aspm = 1;
>> > }
>> > +
>> > + if (!(requested & control & OSC_PCI_EXPRESS_AER_CONTROL))
>>
>> One of the operators above needs to be a && I suppose?
>>
>
> It's a 3-way bitwise AND to check that OSC_PCI_EXPRESS_AER_CONTROL is
> set in both "requested" and "control".
>
> IOW, we check if AER was requested by the OS and that the platform
> granted the request.

OK

I'll queue this up if Bjorn doesn't object, unless Bjorn wants to
apply it himself.

Thanks,
Rafael

2018-01-11 18:09:10

by Bjorn Helgaas

[permalink] [raw]
Subject: Re: [PATCH] PCI/ACPI: Disable AER when _OSC control bit is clear.

On Thu, Jan 11, 2018 at 09:03:16AM -0600, Yazen Ghannam wrote:
> From: Yazen Ghannam <[email protected]>
>
> Currently, aer_service_init() checks if AER is available and that
> Firmware First handling is not enabled. The _OSC request for AER is
> not taken into account when deciding to enable AER in Linux.
>
> We should check that the _OSC control for AER is set. If it's not
> then AER should be disabled.
>
> The _OSC control for AER is not requested when APEI Firmware First is
> used, so the same condition applies.
>
> Mark AER as disabled if the _OSC request was not made or accepted.
>
> Remove redunant check for aer_acpi_firmware_first() when calling
> aer_service_init(), since this is check is already included when
> checking the _OSC control.

s/redunant/redundant/

The concept seems right to me. Please add a citation to the relevant spec
section. I think this is somewhere in the PCI Firmware spec.

> Signed-off-by: Yazen Ghannam <[email protected]>
> ---
> drivers/acpi/pci_root.c | 3 +++
> drivers/pci/pcie/aer/aerdrv.c | 2 +-
> 2 files changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
> index 6fc204a52493..19a625ed8de9 100644
> --- a/drivers/acpi/pci_root.c
> +++ b/drivers/acpi/pci_root.c
> @@ -512,6 +512,9 @@ static void negotiate_os_control(struct acpi_pci_root *root, int *no_aspm)
> */
> *no_aspm = 1;
> }
> +
> + if (!(requested & control & OSC_PCI_EXPRESS_AER_CONTROL))
> + pci_no_aer();
> }
>
> static int acpi_pci_root_add(struct acpi_device *device,
> diff --git a/drivers/pci/pcie/aer/aerdrv.c b/drivers/pci/pcie/aer/aerdrv.c
> index 6ff5f5b4f5e6..39bb059777d0 100644
> --- a/drivers/pci/pcie/aer/aerdrv.c
> +++ b/drivers/pci/pcie/aer/aerdrv.c
> @@ -374,7 +374,7 @@ static void aer_error_resume(struct pci_dev *dev)
> */
> static int __init aer_service_init(void)
> {
> - if (!pci_aer_available() || aer_acpi_firmware_first())
> + if (!pci_aer_available())
> return -ENXIO;
> return pcie_port_service_register(&aerdriver);
> }
> --
> 2.14.1
>
> --
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2018-01-11 19:04:35

by Borislav Petkov

[permalink] [raw]
Subject: Re: [PATCH] PCI/ACPI: Disable AER when _OSC control bit is clear.

On Thu, Jan 11, 2018 at 07:03:23PM +0100, Rafael J. Wysocki wrote:
> >> > + if (!(requested & control & OSC_PCI_EXPRESS_AER_CONTROL))
> >>
> >> One of the operators above needs to be a && I suppose?
> >>
> >
> > It's a 3-way bitwise AND to check that OSC_PCI_EXPRESS_AER_CONTROL is
> > set in both "requested" and "control".
> >
> > IOW, we check if AER was requested by the OS and that the platform
> > granted the request.
>
> OK

This definitely needs a comment - people will keep tripping over this.

--
Regards/Gruss,
Boris.

SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nürnberg)
--

2018-01-12 00:28:15

by Rafael J. Wysocki

[permalink] [raw]
Subject: Re: [PATCH] PCI/ACPI: Disable AER when _OSC control bit is clear.

On Thu, Jan 11, 2018 at 8:04 PM, Borislav Petkov <[email protected]> wrote:
> On Thu, Jan 11, 2018 at 07:03:23PM +0100, Rafael J. Wysocki wrote:
>> >> > + if (!(requested & control & OSC_PCI_EXPRESS_AER_CONTROL))
>> >>
>> >> One of the operators above needs to be a && I suppose?
>> >>
>> >
>> > It's a 3-way bitwise AND to check that OSC_PCI_EXPRESS_AER_CONTROL is
>> > set in both "requested" and "control".
>> >
>> > IOW, we check if AER was requested by the OS and that the platform
>> > granted the request.
>>
>> OK
>
> This definitely needs a comment - people will keep tripping over this.

Fair enough.