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Date:   Mon, 26 Sep 2022 14:31:42 +0300
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To:     Jens Glathe <jens.glathe@oldschoolsolutions.biz>,
        mathias.nyman@intel.com
Cc:     gregkh@linuxfoundation.org, linux-usb@vger.kernel.org,
        linux-kernel@vger.kernel.org
References: <20220925172236.2288-1-jens.glathe@oldschoolsolutions.biz>
From:   Mathias Nyman <mathias.nyman@linux.intel.com>
Subject: Re: [PATCH] fix: add XHCI_SPURIOUS_SUCCESS to ASM1042 despite being a
 V0.96 controller
In-Reply-To: <20220925172236.2288-1-jens.glathe@oldschoolsolutions.biz>
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Hi

Thanks for the patch, some small changes still needed:

Include subsystem in subject line, something like
usb: xhci: Add XHCI_SPURIOUS...

On 25.9.2022 20.22, Jens Glathe wrote:
> only if it reports as a V0.96 XHCI controller. Appears to fix the errors
> "xhci_hcd <address>; ERROR Transfer event TRB DMA ptr not part of
> current TD ep_index 2 comp_code 13" that appear spuriously (or pretty
> often) when using a r8152 USB3 ethernet adapter with integrated hub.
> 
> Signed-off-by: Jens Glathe <jens.glathe@oldschoolsolutions.biz>
> ---
>   drivers/usb/host/xhci-pci.c | 6 +++++-
>   1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c
> index dce6c0ec8d34..d1b8e7148dd1 100644
> --- a/drivers/usb/host/xhci-pci.c
> +++ b/drivers/usb/host/xhci-pci.c
> @@ -306,8 +306,12 @@ static void xhci_pci_quirks(struct device *dev, struct xhci_hcd *xhci)
>   	}
>   
>   	if (pdev->vendor == PCI_VENDOR_ID_ASMEDIA &&
> -		pdev->device == PCI_DEVICE_ID_ASMEDIA_1042_XHCI)
> +		pdev->device == PCI_DEVICE_ID_ASMEDIA_1042_XHCI) {
> +		/* try to tame the ASMedia 1042 controller which is 0.96 */
> +		if (xhci->hci_version == 0x96)

Do we need this 0x96 check? It's anyway set for 1.0 and newer controllers

> +			xhci->quirks |= XHCI_SPURIOUS_SUCCESS;

This reminds me that I should get rid of this quirk.

If we get a short transfers event for a TRB mid TD, then xhci hosts version 1.0 and later
should send a second event for the last TRB in the TD

so this is default behavior for modern xHCI, not a spurious event.

But your patch is anyways needed for stable kernels.

Thanks
-Mathias