[PATCH AUTOSEL 4.19 07/32] xhci: bail out early if driver can't accress host in resume

[PATCH AUTOSEL 4.19 07/32] xhci: bail out early if driver can't accress host in resume

[Sasha Levin]

From: Mathias Nyman <mathias.nyman@linux.intel.com>

[ Upstream commit 72ae194704da212e2ec312ab182a96799d070755 ]

Bail out early if the xHC host needs to be reset at resume
but driver can't access xHC PCI registers.

If xhci driver already fails to reset the controller then there
is no point in attempting to free, re-initialize, re-allocate and
re-start the host. If failure to access the host is detected later,
failing the resume, xhci interrupts will be double freed
when remove is called.

Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20200312144517.1593-2-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/usb/host/xhci.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 65cc362717fcb..b4177287d7d0f 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -1147,8 +1147,10 @@ int xhci_resume(struct xhci_hcd *xhci, bool hibernated)
 		xhci_dbg(xhci, "Stop HCD\n");
 		xhci_halt(xhci);
 		xhci_zero_64b_regs(xhci);
-		xhci_reset(xhci);
+		retval = xhci_reset(xhci);
 		spin_unlock_irq(&xhci->lock);
+		if (retval)
+			return retval;
 		xhci_cleanup_msix(xhci);
 
 		xhci_dbg(xhci, "// Disabling event ring interrupts\n");
-- 
2.20.1

[PATCH AUTOSEL 4.19 23/32] usb: dwc3: core: add support for disabling SS instances in park mode

[Sasha Levin]

From: Neil Armstrong <narmstrong@baylibre.com>

[ Upstream commit 7ba6b09fda5e0cb741ee56f3264665e0edc64822 ]

In certain circumstances, the XHCI SuperSpeed instance in park mode
can fail to recover, thus on Amlogic G12A/G12B/SM1 SoCs when there is high
load on the single XHCI SuperSpeed instance, the controller can crash like:
 xhci-hcd xhci-hcd.0.auto: xHCI host not responding to stop endpoint command.
 xhci-hcd xhci-hcd.0.auto: Host halt failed, -110
 xhci-hcd xhci-hcd.0.auto: xHCI host controller not responding, assume dead
 xhci-hcd xhci-hcd.0.auto: xHCI host not responding to stop endpoint command.
 hub 2-1.1:1.0: hub_ext_port_status failed (err = -22)
 xhci-hcd xhci-hcd.0.auto: HC died; cleaning up
 usb 2-1.1-port1: cannot reset (err = -22)

Setting the PARKMODE_DISABLE_SS bit in the DWC3_USB3_GUCTL1 mitigates
the issue. The bit is described as :
"When this bit is set to '1' all SS bus instances in park mode are disabled"

Synopsys explains:
The GUCTL1.PARKMODE_DISABLE_SS is only available in
dwc_usb3 controller running in host mode.
This should not be set for other IPs.
This can be disabled by default based on IP, but I recommend to have a
property to enable this feature for devices that need this.

CC: Dongjin Kim <tobetter@gmail.com>
Cc: Jianxin Pan <jianxin.pan@amlogic.com>
Cc: Thinh Nguyen <thinhn@synopsys.com>
Cc: Jun Li <lijun.kernel@gmail.com>
Reported-by: Tim <elatllat@gmail.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/usb/dwc3/core.c | 5 +++++
 drivers/usb/dwc3/core.h | 4 ++++
 2 files changed, 9 insertions(+)

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index 6666d2a52bf56..60d08269ad9a0 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -981,6 +981,9 @@ static int dwc3_core_init(struct dwc3 *dwc)
 		if (dwc->dis_tx_ipgap_linecheck_quirk)
 			reg |= DWC3_GUCTL1_TX_IPGAP_LINECHECK_DIS;
 
+		if (dwc->parkmode_disable_ss_quirk)
+			reg |= DWC3_GUCTL1_PARKMODE_DISABLE_SS;
+
 		dwc3_writel(dwc->regs, DWC3_GUCTL1, reg);
 	}
 
@@ -1287,6 +1290,8 @@ static void dwc3_get_properties(struct dwc3 *dwc)
 				"snps,dis-del-phy-power-chg-quirk");
 	dwc->dis_tx_ipgap_linecheck_quirk = device_property_read_bool(dev,
 				"snps,dis-tx-ipgap-linecheck-quirk");
+	dwc->parkmode_disable_ss_quirk = device_property_read_bool(dev,
+				"snps,parkmode-disable-ss-quirk");
 
 	dwc->tx_de_emphasis_quirk = device_property_read_bool(dev,
 				"snps,tx_de_emphasis_quirk");
diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index 131028501752b..e34308d64619e 100644
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -242,6 +242,7 @@
 #define DWC3_GUCTL_HSTINAUTORETRY	BIT(14)
 
 /* Global User Control 1 Register */
+#define DWC3_GUCTL1_PARKMODE_DISABLE_SS	BIT(17)
 #define DWC3_GUCTL1_TX_IPGAP_LINECHECK_DIS	BIT(28)
 #define DWC3_GUCTL1_DEV_L1_EXIT_BY_HW	BIT(24)
 
@@ -992,6 +993,8 @@ struct dwc3_scratchpad_array {
  *			change quirk.
  * @dis_tx_ipgap_linecheck_quirk: set if we disable u2mac linestate
  *			check during HS transmit.
+ * @parkmode_disable_ss_quirk: set if we need to disable all SuperSpeed
+ *			instances in park mode.
  * @tx_de_emphasis_quirk: set if we enable Tx de-emphasis quirk
  * @tx_de_emphasis: Tx de-emphasis value
  * 	0	- -6dB de-emphasis
@@ -1163,6 +1166,7 @@ struct dwc3 {
 	unsigned		dis_u2_freeclk_exists_quirk:1;
 	unsigned		dis_del_phy_power_chg_quirk:1;
 	unsigned		dis_tx_ipgap_linecheck_quirk:1;
+	unsigned		parkmode_disable_ss_quirk:1;
 
 	unsigned		tx_de_emphasis_quirk:1;
 	unsigned		tx_de_emphasis:2;
-- 
2.20.1