Attachment 137764 Details for Bug 75985 – PCI: Enable power to Nvidia HDA controllers on device enumeration

[patch] PCI: Enable power to Nvidia HDA controllers on device enumeration

0001-PCI-Enable-power-to-Nvidia-HDA-controllers-on-device.patch (text/plain), 3.44 KB, created by Lukas Wunner on 2018-03-03 12:24:09 UTC

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Creator: Lukas Wunner

Created: 2018-03-03 12:24:09 UTC

Size: 3.44 KB

patch

obsolete

>From 4b0ffeba41f8331791ec152856c94d7682538c52 Mon Sep 17 00:00:00 2001
>From: Lukas Wunner <lukas@wunner.de>
>Date: Sat, 3 Mar 2018 13:05:36 +0100
>Subject: [PATCH] PCI: Enable power to Nvidia HDA controllers on device
> enumeration
>
>The integrated HDA controller on Nvidia GPUs can be powergated with a
>bit in the GPU's config space.  Some laptop BIOSes power it off unless
>an external display is attached on boot, rendering the HDA controller
>invisible and preventing its use if a display is attached later.
>
>Avoid by enabling power to the HDA controller on device enumeration.
>
>The GPU and HDA controller are two functions of the same PCI device
>(VGA class device on function 0 and audio device on function 1).
>The multifunction bit in the GPU's config space is cleared when the
>HDA controller is powergated and set if it's on, so reinitialize the
>bit after enabling power.
>
>According to Ilia Mirkin, the HDA controller is only present from MCP89
>onward, so do not touch config space on older GPUs.
>
>Link: https://devtalk.nvidia.com/default/topic/1024022
>Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=75985
>Cc: Aaron Plattner <aplattner@nvidia.com>
>Cc: Ilia Mirkin <imirkin@alum.mit.edu>
>Cc: Karol Herbst <kherbst@redhat.com>
>Cc: Daniel Drake <drake@endlessm.com>
>Cc: Maik Freudenberg <hhfeuer@gmx.de>
>Signed-off-by: Lukas Wunner <lukas@wunner.de>
>---
> drivers/pci/quirks.c    | 29 +++++++++++++++++++++++++++++
> include/linux/pci_ids.h |  1 +
> 2 files changed, 30 insertions(+)
>
>diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
>index 2dfc60b..e91af83 100644
>--- a/drivers/pci/quirks.c
>+++ b/drivers/pci/quirks.c
>@@ -4867,3 +4867,32 @@ static void quirk_gpu_hda(struct pci_dev *hda)
> 			      PCI_CLASS_MULTIMEDIA_HD_AUDIO, 8, quirk_gpu_hda);
> DECLARE_PCI_FIXUP_CLASS_FINAL(PCI_VENDOR_ID_NVIDIA, PCI_ANY_ID,
> 			      PCI_CLASS_MULTIMEDIA_HD_AUDIO, 8, quirk_gpu_hda);
>+
>+/*
>+ * The integrated HDA controller on Nvidia GPUs can be powergated with a bit
>+ * in the GPU's config space.  Some laptop BIOSes power it off unless an
>+ * external display is attached on boot, rendering the HDA controller
>+ * invisible and preventing its use if a display is attached later.
>+ * Avoid by enabling power to the HDA controller on device enumeration.
>+ *
>+ * https://devtalk.nvidia.com/default/topic/1024022
>+ */
>+static void quirk_nvidia_hda(struct pci_dev *gpu)
>+{
>+	u8 hdr_type;
>+	u32 val;
>+
>+	/* no HDA controller present before MCP89 */
>+	if (gpu->device < PCI_DEVICE_ID_NVIDIA_GEFORCE_320M)
>+		return;
>+
>+	/* bit 25 at 0x488 powergates the HDA controller */
>+	pci_read_config_dword(gpu, 0x488, &val);
>+	pci_write_config_dword(gpu, 0x488, val | BIT(25));
>+
>+	/* the GPU becomes a multifunction device when the HDA is powered on */
>+	pci_read_config_byte(gpu, PCI_HEADER_TYPE, &hdr_type));
>+	gpu->multifunction = !!(hdr_type & BIT(7));
>+}
>+DECLARE_PCI_FIXUP_CLASS_HEADER(PCI_VENDOR_ID_NVIDIA, PCI_ANY_ID,
>+			       PCI_BASE_CLASS_DISPLAY, 16, quirk_nvidia_hda);
>diff --git a/include/linux/pci_ids.h b/include/linux/pci_ids.h
>index fa6af1e..2464b12 100644
>--- a/include/linux/pci_ids.h
>+++ b/include/linux/pci_ids.h
>@@ -1324,6 +1324,7 @@
> #define PCI_DEVICE_ID_NVIDIA_NFORCE_MCP78S_SMBUS    0x0752
> #define PCI_DEVICE_ID_NVIDIA_NFORCE_MCP77_IDE       0x0759
> #define PCI_DEVICE_ID_NVIDIA_NFORCE_MCP73_SMBUS     0x07D8
>+#define PCI_DEVICE_ID_NVIDIA_GEFORCE_320M           0x08A0
> #define PCI_DEVICE_ID_NVIDIA_NFORCE_MCP79_SMBUS     0x0AA2
> #define PCI_DEVICE_ID_NVIDIA_NFORCE_MCP89_SATA	    0x0D85
> 
>-- 
>2.15.1
>

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