On Thu, Jul 22, 2021 at 9:49 PM Ratchanan Srirattanamet
<peathot@xxxxxxxxxxx> wrote:
>
> Hello,
>
> เมื่อ 22/7/64 เวลา 23:36 Karol Herbst เขียนว่า:
> > hey, thanks for the patch. But I am a bit confused on why that patch
> > actually helps. It should only be called for nvidia GPUs, but are we
> > ending up checking it for AMD GPUs as well?
>
> This is the call site of nouveau_dsm_pci_probe() in nouveau_acpi.c:
>
> /* now do DSM detection */
> while ((pdev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, pdev)) != NULL) {
> vga_count++;
>
> nouveau_dsm_pci_probe(pdev, &dhandle, &has_mux, &has_optimus,
> &has_optimus_flags, &has_power_resources);
> }
> // And repeat with PCI_CLASS_DISPLAY_3D
>
> So, all VGA and 3D cards, Nvidia or not, has this function called. Are
> you suggesting that this should not happen?
>
yeah.. it shouldn't. Although I am not quite sure how pci_get_class
works... I was under the impression it only touches children but I
guess it just iterates through the list of all devices? uhhhh mhhh...
Yeah then I'd see why we never hit this on intel systems as the intel
GPU is usually further up the list.
> > Mind posting the output of lspci -tvnn?
>
> In case it helps, here it is:
>
> $ lspci -tvnn
> -[0000:00]-+-00.0 Advanced Micro Devices, Inc. [AMD] Renoir Root
> Complex [1022:1630]
> +-00.2 Advanced Micro Devices, Inc. [AMD] Renoir IOMMU
> [1022:1631]
> +-01.0 Advanced Micro Devices, Inc. [AMD] Renoir PCIe Dummy
> Host Bridge [1022:1632]
> +-01.1-[01]--+-00.0 NVIDIA Corporation Device [10de:1f95]
> | \-00.1 NVIDIA Corporation Device [10de:10fa]
> +-01.2-[02]----00.0 Micron Technology Inc Device [1344:5405]
> +-02.0 Advanced Micro Devices, Inc. [AMD] Renoir PCIe Dummy
> Host Bridge [1022:1632]
> +-02.1-[03]----00.0 Realtek Semiconductor Co., Ltd.
> RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller [10ec:8168]
> +-02.2-[04]----00.0 Intel Corporation Wi-Fi 6 AX200 [8086:2723]
> +-08.0 Advanced Micro Devices, Inc. [AMD] Renoir PCIe Dummy
> Host Bridge [1022:1632]
> +-08.1-[05]--+-00.0 Advanced Micro Devices, Inc. [AMD/ATI]
> Renoir [1002:1636]
> | +-00.2 Advanced Micro Devices, Inc. [AMD]
> Family 17h (Models 10h-1fh) Platform Security Processor [1022:15df]
> | +-00.3 Advanced Micro Devices, Inc. [AMD]
> Renoir USB 3.1 [1022:1639]
> | +-00.4 Advanced Micro Devices, Inc. [AMD]
> Renoir USB 3.1 [1022:1639]
> | +-00.5 Advanced Micro Devices, Inc. [AMD]
> Raven/Raven2/FireFlight/Renoir Audio Processor [1022:15e2]
> | \-00.6 Advanced Micro Devices, Inc. [AMD]
> Family 17h (Models 10h-1fh) HD Audio Controller [1022:15e3]
> +-08.2-[06]--+-00.0 Advanced Micro Devices, Inc. [AMD] FCH
> SATA Controller [AHCI mode] [1022:7901]
> | \-00.1 Advanced Micro Devices, Inc. [AMD] FCH
> SATA Controller [AHCI mode] [1022:7901]
> +-14.0 Advanced Micro Devices, Inc. [AMD] FCH SMBus
> Controller [1022:790b]
> +-14.3 Advanced Micro Devices, Inc. [AMD] FCH LPC Bridge
> [1022:790e]
> +-18.0 Advanced Micro Devices, Inc. [AMD] Renoir Device 24:
> Function 0 [1022:1448]
> +-18.1 Advanced Micro Devices, Inc. [AMD] Renoir Device 24:
> Function 1 [1022:1449]
> +-18.2 Advanced Micro Devices, Inc. [AMD] Renoir Device 24:
> Function 2 [1022:144a]
> +-18.3 Advanced Micro Devices, Inc. [AMD] Renoir Device 24:
> Function 3 [1022:144b]
> +-18.4 Advanced Micro Devices, Inc. [AMD] Renoir Device 24:
> Function 4 [1022:144c]
> +-18.5 Advanced Micro Devices, Inc. [AMD] Renoir Device 24:
> Function 5 [1022:144d]
> +-18.6 Advanced Micro Devices, Inc. [AMD] Renoir Device 24:
> Function 6 [1022:144e]
> \-18.7 Advanced Micro Devices, Inc. [AMD] Renoir Device 24:
> Function 7 [1022:144f]
>
> Ratchanan Srirattanamet
>
> > On Thu, Jul 22, 2021 at 5:10 AM Ratchanan Srirattanamet
> > <peathot@xxxxxxxxxxx> wrote:
> >>
> >> The call site of nouveau_dsm_pci_probe() uses single set of output
> >> variables for all invocations. So, we must not write anything to them
> >> until we think this is an NVIDIA device of interest. Otherwise, if we
> >> are called with another device after the NVIDIA device, we'll clober the
> >> result of the NVIDIA device.
> >>
> >> In this case, if the other device doesn't have _PR3 resources, the
> >> detection later would miss the presence of power resource support, and
> >> the rest of the code will keep using Optimus DSM, breaking power
> >> management for that machine. In particular, this fixes power management
> >> of the NVIDIA card in Lenovo Legion 5-15ARH05... well, at least
> >> partially. New error shows up, but this patch is correct in itself
> >> anyway.
> >>
> >> As a bonus, we'll also stop preventing _PR3 usage from the bridge for
> >> unrelated devices, which is always nice, I guess.
> >>
> >> As noted in commit ccfc2d5cdb024 ("drm/nouveau: Use generic helper to
> >> check _PR3 presence"), care is taken to leave the _PR3 detection outside
> >> of the optimus_func condition.
> >>
> >> https://gitlab.freedesktop.org/drm/nouveau/-/issues/79
> >>
> >> Fixes: ccfc2d5cdb024 ("drm/nouveau: Use generic helper to check _PR3
> >> presence")
> >> Signed-off-by: Ratchanan Srirattanamet <peathot@xxxxxxxxxxx>
> >> ---
> >>
> >> Hello,
> >>
> >> This is my first time submitting a Linux patch. I've done a
> >> number of PR/MR workflows on GitHub or GitLab, but never done any
> >> email-oriented development. So, please excuse me if I'm doing something
> >> incorrectly.
> >>
> >> drivers/gpu/drm/nouveau/nouveau_acpi.c | 18 +++++++++---------
> >> 1 file changed, 9 insertions(+), 9 deletions(-)
> >>
> >> diff --git a/drivers/gpu/drm/nouveau/nouveau_acpi.c b/drivers/gpu/drm/nouveau/nouveau_acpi.c
> >> index 7c15f6448428..c88bda3ac820 100644
> >> --- a/drivers/gpu/drm/nouveau/nouveau_acpi.c
> >> +++ b/drivers/gpu/drm/nouveau/nouveau_acpi.c
> >> @@ -220,15 +220,6 @@ static void nouveau_dsm_pci_probe(struct pci_dev *pdev, acpi_handle *dhandle_out
> >> int optimus_funcs;
> >> struct pci_dev *parent_pdev;
> >>
> >> - *has_pr3 = false;
> >> - parent_pdev = pci_upstream_bridge(pdev);
> >> - if (parent_pdev) {
> >> - if (parent_pdev->bridge_d3)
> >> - *has_pr3 = pci_pr3_present(parent_pdev);
> >> - else
> >> - pci_d3cold_disable(pdev);
> >> - }
> >> -
> >> dhandle = ACPI_HANDLE(&pdev->dev);
> >> if (!dhandle)
> >> return;
> >> @@ -249,6 +240,15 @@ static void nouveau_dsm_pci_probe(struct pci_dev *pdev, acpi_handle *dhandle_out
> >> *has_opt = !!optimus_funcs;
> >> *has_opt_flags = optimus_funcs & (1 << NOUVEAU_DSM_OPTIMUS_FLAGS);
> >>
> >> + *has_pr3 = false;
> >> + parent_pdev = pci_upstream_bridge(pdev);
> >> + if (parent_pdev) {
> >> + if (parent_pdev->bridge_d3)
> >> + *has_pr3 = pci_pr3_present(parent_pdev);
> >> + else
> >> + pci_d3cold_disable(pdev);
> >> + }
> >> +
> >> if (optimus_funcs) {
> >> uint32_t result;
> >> nouveau_optimus_dsm(dhandle, NOUVEAU_DSM_OPTIMUS_CAPS, 0,
> >> --
> >> 2.25.1
> >>
> >> _______________________________________________
> >> Nouveau mailing list
> >> Nouveau@xxxxxxxxxxxxxxxxxxxxx
> >> https://lists.freedesktop.org/mailman/listinfo/nouveau
> >>
> >
>
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