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Subject: Re: [PATCH v3] xhci: Prevent runtime suspend on Etron EJ168
From:   Kai-Heng Feng <kai.heng.feng@canonical.com>
In-Reply-To: <20200504171642.26947-1-kai.heng.feng@canonical.com>
Date:   Mon, 8 Jun 2020 11:56:08 +0800
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        "open list:USB XHCI DRIVER" <linux-usb@vger.kernel.org>,
        open list <linux-kernel@vger.kernel.org>
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References: <20200504171642.26947-1-kai.heng.feng@canonical.com>
To:     Mathias Nyman <mathias.nyman@intel.com>
Sender: linux-kernel-owner@vger.kernel.org
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> On May 5, 2020, at 01:16, Kai-Heng Feng <kai.heng.feng@canonical.com> wrote:
> 
> Etron EJ168 USB 3.0 Host Controller stops working after S3, if it was
> runtime suspended previously:
> [  370.080359] pci 0000:02:00.0: can't change power state from D3cold to D0 (config space inaccessible)
> [  370.080477] xhci_hcd 0000:04:00.0: can't change power state from D3cold to D0 (config space inaccessible)
> [  370.080532] pcieport 0000:00:1c.0: DPC: containment event, status:0x1f05 source:0x0200
> [  370.080533] pcieport 0000:00:1c.0: DPC: ERR_FATAL detected
> [  370.080536] xhci_hcd 0000:04:00.0: can't change power state from D3hot to D0 (config space inaccessible)
> [  370.080552] xhci_hcd 0000:04:00.0: AER: can't recover (no error_detected callback)
> [  370.080566] usb usb3: root hub lost power or was reset
> [  370.080566] usb usb4: root hub lost power or was reset
> [  370.080572] xhci_hcd 0000:04:00.0: Host halt failed, -19
> [  370.080574] xhci_hcd 0000:04:00.0: Host not accessible, reset failed.
> [  370.080575] xhci_hcd 0000:04:00.0: PCI post-resume error -19!
> [  370.080586] xhci_hcd 0000:04:00.0: HC died; cleaning up
> 
> This can be fixed by not runtime suspend the controller at all.
> 
> So disable runtime suspend for EJ168 xHCI device.
> 
> Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>

A gentle ping...

> ---
> v3:
> - Balance rpm refcount in remove callback.
> 
> v2:
> - Use a new quirk to avoid changing existing behavior.
> 
> drivers/usb/host/xhci-pci.c | 7 ++++++-
> drivers/usb/host/xhci.h     | 1 +
> 2 files changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c
> index 766b74723e64..67b4b433a93e 100644
> --- a/drivers/usb/host/xhci-pci.c
> +++ b/drivers/usb/host/xhci-pci.c
> @@ -227,6 +227,7 @@ static void xhci_pci_quirks(struct device *dev, struct xhci_hcd *xhci)
> 		xhci->quirks |= XHCI_RESET_ON_RESUME;
> 		xhci->quirks |= XHCI_TRUST_TX_LENGTH;
> 		xhci->quirks |= XHCI_BROKEN_STREAMS;
> +		xhci->quirks |= XHCI_DISABLE_RUNTIME_SUSPEND;
> 	}
> 	if (pdev->vendor == PCI_VENDOR_ID_RENESAS &&
> 	    pdev->device == 0x0014) {
> @@ -371,7 +372,8 @@ static int xhci_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
> 		xhci->shared_hcd->can_do_streams = 1;
> 
> 	/* USB-2 and USB-3 roothubs initialized, allow runtime pm suspend */
> -	pm_runtime_put_noidle(&dev->dev);
> +	if (!(xhci->quirks & XHCI_DISABLE_RUNTIME_SUSPEND))
> +		pm_runtime_put_noidle(&dev->dev);
> 
> 	if (xhci->quirks & XHCI_DEFAULT_PM_RUNTIME_ALLOW)
> 		pm_runtime_allow(&dev->dev);
> @@ -397,6 +399,9 @@ static void xhci_pci_remove(struct pci_dev *dev)
> 	if (xhci->quirks & XHCI_DEFAULT_PM_RUNTIME_ALLOW)
> 		pm_runtime_forbid(&dev->dev);
> 
> +	if (!(xhci->quirks & XHCI_DISABLE_RUNTIME_SUSPEND))
> +		pm_runtime_get_noresume(&dev->dev);
> +
> 	if (xhci->shared_hcd) {
> 		usb_remove_hcd(xhci->shared_hcd);
> 		usb_put_hcd(xhci->shared_hcd);
> diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
> index 86cfefdd6632..d9c209a10d3f 100644
> --- a/drivers/usb/host/xhci.h
> +++ b/drivers/usb/host/xhci.h
> @@ -1873,6 +1873,7 @@ struct xhci_hcd {
> #define XHCI_DEFAULT_PM_RUNTIME_ALLOW	BIT_ULL(33)
> #define XHCI_RESET_PLL_ON_DISCONNECT	BIT_ULL(34)
> #define XHCI_SNPS_BROKEN_SUSPEND    BIT_ULL(35)
> +#define XHCI_DISABLE_RUNTIME_SUSPEND    BIT_ULL(36)
> 
> 	unsigned int		num_active_eps;
> 	unsigned int		limit_active_eps;
> -- 
> 2.17.1
>