[D/Unstable/OEM-OSP1-B,1/1] PCI: Enable NVIDIA HDA controllers
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Message ID 20190712063431.3085-3-kai.heng.feng@canonical.com
State New
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  • [D/Unstable/OEM-OSP1-B,1/1] PCI: Enable NVIDIA HDA controllers
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Commit Message

Kai-Heng Feng July 12, 2019, 6:34 a.m. UTC
From: Lukas Wunner <lukas@wunner.de>

BugLink: https://bugs.launchpad.net/bugs/1836308

Many NVIDIA GPUs can be configured as either a single-function video device
or a multi-function device with video at function 0 and an HDA audio
controller at function 1.  The HDA controller can be enabled or disabled by
a bit in the function 0 config space.

Some BIOSes leave the HDA disabled, which means the HDMI connector from the
NVIDIA GPU may not work.  Sometimes the BIOS enables the HDA if an HDMI
cable is connected at boot time, but that doesn't handle hotplug cases.

Enable the HDA controller on device enumeration and resume and re-read the
header type, which tells us whether the GPU is a multi-function device.

This quirk is limited to NVIDIA PCI devices with the VGA Controller device
class.  This is expected to correspond to product configurations where the
NVIDIA GPU has connectors attached.  Other products where the device class
is 3D Controller are expected to correspond to configurations where the
NVIDIA GPU is dedicated (dGPU) and has no connectors.  See original post
(URL below) for more details.

This commit takes inspiration from an earlier patch by Daniel Drake.

Link: https://lore.kernel.org/r/20190708051744.24039-1-drake@endlessm.com
Link: https://devtalk.nvidia.com/default/topic/1024022
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=75985
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Daniel Drake <drake@endlessm.com>
[bhelgaas: commit log, log message, return early if already enabled]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Aaron Plattner <aplattner@nvidia.com>
Cc: Peter Wu <peter@lekensteyn.nl>
Cc: Ilia Mirkin <imirkin@alum.mit.edu>
Cc: Karol Herbst <kherbst@redhat.com>
Cc: Maik Freudenberg <hhfeuer@gmx.de>
(backported from commit b678f90a1a6f8899542ea7bb190e268fb2d6ea0d git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci.git pci/misc)
Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
 drivers/pci/quirks.c    | 30 ++++++++++++++++++++++++++++++
 include/linux/pci_ids.h |  1 +
 2 files changed, 31 insertions(+)

diff mbox series

diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index da6ce46ce3f0..6140de200ae6 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
 			      PCI_CLASS_MULTIMEDIA_HD_AUDIO, 8, quirk_gpu_hda);
+ * Enable the NVIDIA GPU integrated HDA controller if the BIOS left it
+ * disabled.  https://devtalk.nvidia.com/default/topic/1024022
+ */
+static void quirk_nvidia_hda(struct pci_dev *gpu)
+	u8 hdr_type;
+	u32 val;
+	/* There was no integrated HDA controller before MCP89 */
+	if (gpu->device < PCI_DEVICE_ID_NVIDIA_GEFORCE_320M)
+		return;
+	/* Bit 25 at offset 0x488 enables the HDA controller */
+	pci_read_config_dword(gpu, 0x488, &val);
+	if (val & BIT(25))
+		return;
+	pci_info(gpu, "Enabling HDA controller\n");
+	pci_write_config_dword(gpu, 0x488, val | BIT(25));
+	/* The GPU becomes a multi-function device when the HDA is enabled */
+	pci_read_config_byte(gpu, PCI_HEADER_TYPE, &hdr_type);
+	gpu->multifunction = !!(hdr_type & 0x80);
+			       PCI_BASE_CLASS_DISPLAY, 16, quirk_nvidia_hda);
+			       PCI_BASE_CLASS_DISPLAY, 16, quirk_nvidia_hda);
  * Some IDT switches incorrectly flag an ACS Source Validation error on
  * completions for config read requests even though PCIe r4.0, sec
diff --git a/include/linux/pci_ids.h b/include/linux/pci_ids.h
index 44e07bd7e7ee..d88bf2eabdb9 100644
--- a/include/linux/pci_ids.h
+++ b/include/linux/pci_ids.h
@@ -1336,6 +1336,7 @@ 
 #define PCI_DEVICE_ID_NVIDIA_NFORCE_MCP77_IDE       0x0759
+#define PCI_DEVICE_ID_NVIDIA_GEFORCE_320M           0x08A0