LKML Archive on lore.kernel.org
 help / color / Atom feed
* [PATCH 1/2] PCI/ACPI: correct error message for ASPM disabling
@ 2018-08-09 18:46 Sinan Kaya
  2018-08-09 18:46 ` [PATCH 2/2] PCI/ACPI: allow _OSC presence to be optional for PCI Sinan Kaya
  2018-08-10  0:27 ` [PATCH 1/2] PCI/ACPI: correct error message for ASPM disabling Joe Perches
  0 siblings, 2 replies; 4+ messages in thread
From: Sinan Kaya @ 2018-08-09 18:46 UTC (permalink / raw)
  To: linux-pci
  Cc: Sinan Kaya, Bjorn Helgaas, Rafael J. Wysocki, Len Brown,
	linux-acpi, linux-kernel

If _OSC execution fails today for platforms without an _OSC
entry, code is printing a misleading message saying disabling
ASPM as follows:

acpi PNP0A03:00: _OSC failed (AE_NOT_FOUND); disabling ASPM

We need to ensure that platform supports ASPM to begin with.

Signed-off-by: Sinan Kaya <okaya@kernel.org>
Reported-by: Michael Kelley <mikelley@microsoft.com>
---
 drivers/acpi/pci_root.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
index 7433035..9d738e2 100644
--- a/drivers/acpi/pci_root.c
+++ b/drivers/acpi/pci_root.c
@@ -455,8 +455,13 @@ static void negotiate_os_control(struct acpi_pci_root *root, int *no_aspm)
 	decode_osc_support(root, "OS supports", support);
 	status = acpi_pci_osc_support(root, support);
 	if (ACPI_FAILURE(status)) {
-		dev_info(&device->dev, "_OSC failed (%s); disabling ASPM\n",
-			 acpi_format_exception(status));
+		char *aspm_msg = "";
+
+		if (pcie_aspm_support_enabled())
+			aspm_msg = "; disabling ASPM";
+
+		dev_info(&device->dev, "_OSC failed (%s) %s\n",
+				 acpi_format_exception(status), aspm_msg);
 		*no_aspm = 1;
 		return;
 	}
-- 
2.7.4


^ permalink raw reply	[flat|nested] 4+ messages in thread

* [PATCH 2/2] PCI/ACPI: allow _OSC presence to be optional for PCI
  2018-08-09 18:46 [PATCH 1/2] PCI/ACPI: correct error message for ASPM disabling Sinan Kaya
@ 2018-08-09 18:46 ` Sinan Kaya
  2018-08-10  0:27 ` [PATCH 1/2] PCI/ACPI: correct error message for ASPM disabling Joe Perches
  1 sibling, 0 replies; 4+ messages in thread
From: Sinan Kaya @ 2018-08-09 18:46 UTC (permalink / raw)
  To: linux-pci
  Cc: Sinan Kaya, Bjorn Helgaas, Rafael J. Wysocki, Len Brown,
	linux-acpi, linux-kernel

ACPI Spec 6.0 Section 6.2.11.3 OSC Implementation Example for PCI
Host Bridge Devices:

For a host bridge device that originates a PCI Express hierarchy,
the _OSC interface defined in this section is required.

For a host bridge device that originates a PCI/PCI-X bus hierarchy,
inclusion of an _OSC object is optional.

Allow PCI host bridges to bail out silently if _OSC is not found.

Signed-off-by: Sinan Kaya <okaya@kernel.org>
Reported-by: Michael Kelley <mikelley@microsoft.com>
---
 drivers/acpi/pci_root.c | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
index 9d738e2..c94ed01 100644
--- a/drivers/acpi/pci_root.c
+++ b/drivers/acpi/pci_root.c
@@ -421,7 +421,8 @@ acpi_status acpi_pci_osc_control_set(acpi_handle handle, u32 *mask, u32 req)
 }
 EXPORT_SYMBOL(acpi_pci_osc_control_set);
 
-static void negotiate_os_control(struct acpi_pci_root *root, int *no_aspm)
+static void negotiate_os_control(struct acpi_pci_root *root, int *no_aspm,
+				 bool is_pcie)
 {
 	u32 support, control, requested;
 	acpi_status status;
@@ -460,9 +461,14 @@ static void negotiate_os_control(struct acpi_pci_root *root, int *no_aspm)
 		if (pcie_aspm_support_enabled())
 			aspm_msg = "; disabling ASPM";
 
-		dev_info(&device->dev, "_OSC failed (%s) %s\n",
-				 acpi_format_exception(status), aspm_msg);
 		*no_aspm = 1;
+
+		/* _OSC is optional for PCI host bridges */
+		if ((status == AE_NOT_FOUND) && !is_pcie)
+			return;
+
+		dev_info(&device->dev, "_OSC failed (%s) %s\n",
+			 acpi_format_exception(status), aspm_msg);
 		return;
 	}
 
@@ -538,6 +544,7 @@ static int acpi_pci_root_add(struct acpi_device *device,
 	acpi_handle handle = device->handle;
 	int no_aspm = 0;
 	bool hotadd = system_state == SYSTEM_RUNNING;
+	bool is_pcie;
 
 	root = kzalloc(sizeof(struct acpi_pci_root), GFP_KERNEL);
 	if (!root)
@@ -595,7 +602,8 @@ static int acpi_pci_root_add(struct acpi_device *device,
 
 	root->mcfg_addr = acpi_pci_root_get_mcfg_addr(handle);
 
-	negotiate_os_control(root, &no_aspm);
+	is_pcie = strcmp(acpi_device_hid(device), "PNP0A08") == 0;
+	negotiate_os_control(root, &no_aspm, is_pcie);
 
 	/*
 	 * TBD: Need PCI interface for enumeration/configuration of roots.
-- 
2.7.4


^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH 1/2] PCI/ACPI: correct error message for ASPM disabling
  2018-08-09 18:46 [PATCH 1/2] PCI/ACPI: correct error message for ASPM disabling Sinan Kaya
  2018-08-09 18:46 ` [PATCH 2/2] PCI/ACPI: allow _OSC presence to be optional for PCI Sinan Kaya
@ 2018-08-10  0:27 ` Joe Perches
  2018-08-10  2:15   ` Sinan Kaya
  1 sibling, 1 reply; 4+ messages in thread
From: Joe Perches @ 2018-08-10  0:27 UTC (permalink / raw)
  To: Sinan Kaya, linux-pci
  Cc: Bjorn Helgaas, Rafael J. Wysocki, Len Brown, open list:ACPI, open list

On Thu, 2018-08-09 at 18:46 +0000, Sinan Kaya wrote:
> If _OSC execution fails today for platforms without an _OSC
> entry, code is printing a misleading message saying disabling
> ASPM as follows:
> 
> acpi PNP0A03:00: _OSC failed (AE_NOT_FOUND); disabling ASPM
> 
> We need to ensure that platform supports ASPM to begin with.
> 
> Signed-off-by: Sinan Kaya <okaya@kernel.org>
> Reported-by: Michael Kelley <mikelley@microsoft.com>
> ---
>  drivers/acpi/pci_root.c | 9 +++++++--
>  1 file changed, 7 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
[]
> @@ -455,8 +455,13 @@ static void negotiate_os_control(struct acpi_pci_root *root, int *no_aspm)
>  	decode_osc_support(root, "OS supports", support);
>  	status = acpi_pci_osc_support(root, support);
>  	if (ACPI_FAILURE(status)) {
> -		dev_info(&device->dev, "_OSC failed (%s); disabling ASPM\n",
> -			 acpi_format_exception(status));
> +		char *aspm_msg = "";
> +
> +		if (pcie_aspm_support_enabled())
> +			aspm_msg = "; disabling ASPM";
> +
> +		dev_info(&device->dev, "_OSC failed (%s) %s\n",
> +				 acpi_format_exception(status), aspm_msg);

I think this would read better not using a temporary and
using a ternary instead.

		dev_info(&device->dev, "_OSC failed (%s)%s\n",
			 acpi_format_exception(status),
			 pcie_aspm_support_enabled() ? "; disabling ASPM" : "");

>  		*no_aspm = 1;
>  		return;
>  	}

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH 1/2] PCI/ACPI: correct error message for ASPM disabling
  2018-08-10  0:27 ` [PATCH 1/2] PCI/ACPI: correct error message for ASPM disabling Joe Perches
@ 2018-08-10  2:15   ` Sinan Kaya
  0 siblings, 0 replies; 4+ messages in thread
From: Sinan Kaya @ 2018-08-10  2:15 UTC (permalink / raw)
  To: Joe Perches, linux-pci
  Cc: Bjorn Helgaas, Rafael J. Wysocki, Len Brown, open list:ACPI, open list

On 8/9/2018 8:27 PM, Joe Perches wrote:
> I think this would read better not using a temporary and
> using a ternary instead.

Makes sense.

^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, back to index

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2018-08-09 18:46 [PATCH 1/2] PCI/ACPI: correct error message for ASPM disabling Sinan Kaya
2018-08-09 18:46 ` [PATCH 2/2] PCI/ACPI: allow _OSC presence to be optional for PCI Sinan Kaya
2018-08-10  0:27 ` [PATCH 1/2] PCI/ACPI: correct error message for ASPM disabling Joe Perches
2018-08-10  2:15   ` Sinan Kaya

LKML Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/lkml/0 lkml/git/0.git
	git clone --mirror https://lore.kernel.org/lkml/1 lkml/git/1.git
	git clone --mirror https://lore.kernel.org/lkml/2 lkml/git/2.git
	git clone --mirror https://lore.kernel.org/lkml/3 lkml/git/3.git
	git clone --mirror https://lore.kernel.org/lkml/4 lkml/git/4.git
	git clone --mirror https://lore.kernel.org/lkml/5 lkml/git/5.git
	git clone --mirror https://lore.kernel.org/lkml/6 lkml/git/6.git
	git clone --mirror https://lore.kernel.org/lkml/7 lkml/git/7.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 lkml lkml/ https://lore.kernel.org/lkml \
		linux-kernel@vger.kernel.org linux-kernel@archiver.kernel.org
	public-inbox-index lkml


Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-kernel


AGPL code for this site: git clone https://public-inbox.org/ public-inbox