linux-kernel - Re: [PATCH v2] usb: xhci: only set D3hot for pci device

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <7aa0d839-57f8-54af-4b55-b3e605ae20cc@linux.intel.com>
Date:   Fri, 15 Nov 2019 17:05:31 +0200
From:   Mathias Nyman <mathias.nyman@...ux.intel.com>
To:     Henry Lin <henryl@...dia.com>
Cc:     hch@...radead.org, Mathias Nyman <mathias.nyman@...el.com>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        linux-usb@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2] usb: xhci: only set D3hot for pci device

On 13.11.2019 3.49, Henry Lin wrote:
> Xhci driver cannot call pci_set_power_state() on non-pci xhci host
> controllers. For example, NVIDIA Tegra XHCI host controller which acts
> as platform device with XHCI_SPURIOUS_WAKEUP quirk set in some platform
> hits this issue during shutdown.
> 

The XHCI_SPURIOUS_WAKEUP quirk both resets the controller at shutdown
and sets it to PCI D3 at remove/shutdown.

Is it so that the NVIDIA Tegra xHC just needs to be reset at shutdown?
The quirk is not set for Tegra xHC in current mainline kernel.

> Signed-off-by: Henry Lin <henryl@...dia.com>
> ---
>   drivers/usb/host/xhci.c | 7 +++++--
>   1 file changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
> index 6c17e3fe181a..61718b126d2b 100644
> --- a/drivers/usb/host/xhci.c
> +++ b/drivers/usb/host/xhci.c
> @@ -791,8 +791,11 @@ static void xhci_shutdown(struct usb_hcd *hcd)
>   			readl(&xhci->op_regs->status));
>   
>   	/* Yet another workaround for spurious wakeups at shutdown with HSW */
> -	if (xhci->quirks & XHCI_SPURIOUS_WAKEUP)
> -		pci_set_power_state(to_pci_dev(hcd->self.sysdev), PCI_D3hot);
> +	if (xhci->quirks & XHCI_SPURIOUS_WAKEUP) {
> +		if (dev_is_pci(hcd->self.sysdev))
> +			pci_set_power_state(to_pci_dev(hcd->self.sysdev),
> +					PCI_D3hot);
> +	}

Agree that we shouldn't call PCI specific functions in the generic shutdown code.
Would be better if we could move the PCI parts to xhci-pci.c or hcd-pci.c

Maybe we need to add a xhci_pci_shutdown() function for the xhci pci driver
that could take care of the pci related shutdown quirks before calling
usb_hcd_pci_shutdown(), and call that instead of directly calling
usb_hcd_pci_shutdown().

-Mathias