Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
From:   Kai-Heng Feng <kai.heng.feng@canonical.com>
To:     mathias.nyman@intel.com
Cc:     Kai-Heng Feng <kai.heng.feng@canonical.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        linux-usb@vger.kernel.org (open list:USB XHCI DRIVER),
        linux-kernel@vger.kernel.org (open list)
Subject: [PATCH v3] xhci: Prevent runtime suspend on Etron EJ168
Date:   Tue,  5 May 2020 01:16:42 +0800
Message-Id: <20200504171642.26947-1-kai.heng.feng@canonical.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

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>
---
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