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Message-ID: <6a710423-e76c-437e-ba59-b9cefbda3194@moonlit-rail.com>
Date: Sat, 2 Dec 2023 01:43:16 -0500
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Subject: Re: Regression: Inoperative bluetooth, Intel chipset, mainline kernel
 6.6.2+
To: Greg KH <gregkh@linuxfoundation.org>,
 Thorsten Leemhuis <regressions@leemhuis.info>
Cc: "stable@vger.kernel.org" <stable@vger.kernel.org>,
 Linux kernel regressions list <regressions@lists.linux.dev>,
 linux-bluetooth@vger.kernel.org,
 Basavaraj Natikar <Basavaraj.Natikar@amd.com>
References: <ee109942-ef8e-45b9-8cb9-a98a787fe094@moonlit-rail.com>
 <8d6070c8-3f82-4a12-8c60-7f1862fef9d9@leemhuis.info>
 <2023120119-bonus-judgingly-bf57@gregkh>
Content-Language: en-US, en-GB
From: "Kris Karas (Bug Reporting)" <bugs-a21@moonlit-rail.com>
In-Reply-To: <2023120119-bonus-judgingly-bf57@gregkh>
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Greg KH wrote:
> On Fri, Dec 01, 2023 at 07:33:03AM +0100, Thorsten Leemhuis wrote:
>> CCing a few lists and people. Greg is among them, who might know if this
>> is a known issue that 6.6.4-rc1 et. al. might already fix.
> 
> Not known to me, bisection is needed so we can track down the problem
> please.

And the winner is...

> commit 14a51fa544225deb9ac2f1f9f3c10dedb29f5d2f
> Author: Basavaraj Natikar <Basavaraj.Natikar@amd.com>
> Date:   Thu Oct 19 13:29:19 2023 +0300
> 
>     xhci: Loosen RPM as default policy to cover for AMD xHC 1.1
>     
>     [ Upstream commit 4baf1218150985ee3ab0a27220456a1f027ea0ac ]
>     
>     The AMD USB host controller (1022:43f7) isn't going into PCI D3 by default
>     without anything connected. This is because the policy that was introduced
>     by commit a611bf473d1f ("xhci-pci: Set runtime PM as default policy on all
>     xHC 1.2 or later devices") only covered 1.2 or later.
>     
> [ snip ]
> diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c
> index b9ae5c2a2527..bde43cef8846 100644
> --- a/drivers/usb/host/xhci-pci.c
> +++ b/drivers/usb/host/xhci-pci.c
> @@ -535,6 +535,8 @@ static void xhci_pci_quirks(struct device *dev, struct xhci_hcd *xhci)
>         /* xHC spec requires PCI devices to support D3hot and D3cold */
>         if (xhci->hci_version >= 0x120)
>                 xhci->quirks |= XHCI_DEFAULT_PM_RUNTIME_ALLOW;
> +       else if (pdev->vendor == PCI_VENDOR_ID_AMD && xhci->hci_version >= 0x110)
> +               xhci->quirks |= XHCI_DEFAULT_PM_RUNTIME_ALLOW;
>  
>         if (xhci->quirks & XHCI_RESET_ON_RESUME)
>                 xhci_dbg_trace(xhci, trace_xhci_dbg_quirks,


Huh, OK, I was expecting this to be a patch made to the bluetooth code, 
as it caused bluetoothd to bomb with "opcode 0x0c03 failed".  But I just 
verified I did the bisect correctly by backing this two-liner out of 
vanilla 6.6.3, and bluetooth returned to normal operation.  Huzzah!

Just a brief recap:

This bug appears to be rather hardware-specific, as only a few folks 
have reported it.  In my case, the hardware is an ASrock "X470 Taichi" 
motherboard, and its on-board bluetooth hardware, reporting itself as:
lspci: 0f:00.3 USB controller: Advanced Micro Devices, Inc. [AMD] 
Zeppelin USB 3.0 xHCI Compliant Host Controller
lsusb: ID 8087:0aa7 Intel Corp. Wireless-AC 3168 Bluetooth

When Basavaraj's patch is applied (in mainline 6.6.2+), bluetooth stops 
functioning on my motherboard.

Originally from bugzilla #218142

-- 
Kris