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

From: Yazen Ghannam <Yazen.Ghannam@amd.com>
To: linux-acpi@vger.kernel.org
Cc: linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org,
	rjw@rjwysocki.net, lenb@kernel.org, bhelgaas@google.com,
	bp@suse.de, Yazen Ghannam <yazen.ghannam@amd.com>
Subject: [PATCH] PCI/ACPI: Disable AER when _OSC control bit is clear.
Date: Thu, 11 Jan 2018 09:03:16 -0600	[thread overview]
Message-ID: <20180111150316.19951-1-Yazen.Ghannam@amd.com> (raw)

From: Yazen Ghannam <yazen.ghannam@amd.com>

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 <yazen.ghannam@amd.com>
---
 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
