[PATCH v3 4/5] usb: dwc3: Add quirk for Synopsis device disconnection errata

Sneeker Yeh
2015-01-25T08:15:24Z

Synopsis Designware USB3 IP earlier than v3.00a which is configured in silicon
with DWC_USB3_SUSPEND_ON_DISCONNECT_EN=1, would need a specific quirk to prevent
xhci host controller from dying when device is disconnected.

Since DWC_USB3_SUSPEND_ON_DISCONNECT_EN is an IP configuration whose state
cannot be checked from software in runtime, it has to be enabled via platform
data or device tree.

Signed-off-by: Sneeker Yeh <Sneeker.Yeh@tw.fujitsu.com>
---
Documentation/devicetree/bindings/usb/dwc3.txt | 17 +++++++++++++++++
drivers/usb/dwc3/core.c | 6 ++++++
drivers/usb/dwc3/core.h | 4 ++++
drivers/usb/dwc3/host.c | 4 ++++
drivers/usb/dwc3/platform_data.h | 8 ++++++++
5 files changed, 39 insertions(+)

diff --git a/Documentation/devicetree/bindings/usb/dwc3.txt b/Documentation/devicetree/bindings/usb/dwc3.txt
index cd7f045..1b78b29 100644
--- a/Documentation/devicetree/bindings/usb/dwc3.txt
+++ b/Documentation/devicetree/bindings/usb/dwc3.txt
@@ -37,6 +37,23 @@ Optional properties:
- snps,is-utmi-l1-suspend: true when DWC3 asserts output signal
utmi_l1_suspend_n, false when asserts utmi_sleep_n
- snps,hird-threshold: HIRD threshold
+ - snps,has_suspend_on_disconnect: true when IP is configured in silicon with
+ DWC_USB3_SUSPEND_ON_DISCONNECT_EN=1, it can inject a
+ specific quirk to prevent xhci host controller from
+ dying when usb device is disconnected from root hub.
+ Since DWC_USB3_SUSPEND_ON_DISCONNECT_EN is an IP
+ configuration whose state cannot be checked from
+ software in runtime, it has to be enabled via platform
+ data or device tree.
+
+ xhci host dying symptom here is caused by that
+ DWC_USB3_SUSPEND_ON_DISCONNECT_EN=1
+ configuration makes IP auto-suspended after PORTCSC is
+ cleared when usb device detached, then an asynchronous
+ disconnection procedure might fail using endpoint
+ command that suspened IP won't have any response to.
+
+ this issue is fixed when IP version >= 3.00a.

This is usually a subnode to DWC3 glue to which it is connected.

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index 25ddc39..fbceab1 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -838,6 +838,9 @@ static int dwc3_probe(struct platform_device *pdev)
"snps,tx_de_emphasis_quirk");
of_property_read_u8(node, "snps,tx_de_emphasis",
&tx_de_emphasis);
+
+ dwc->suspend_on_disconnect_quirk = of_property_read_bool(node,
+ "snps,has_suspend_on_disconnect");
} else if (pdata) {
dwc->maximum_speed = pdata->maximum_speed;
dwc->has_lpm_erratum = pdata->has_lpm_erratum;
@@ -864,6 +867,9 @@ static int dwc3_probe(struct platform_device *pdev)
dwc->tx_de_emphasis_quirk = pdata->tx_de_emphasis_quirk;
if (pdata->tx_de_emphasis)
tx_de_emphasis = pdata->tx_de_emphasis;
+
+ dwc->suspend_on_disconnect_quirk =
+ pdata->has_suspend_on_disconnect;
}

/* default to superspeed if no maximum_speed passed */
diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index 46f9f9a..c730190 100644
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -692,6 +692,9 @@ struct dwc3_scratchpad_array {
* @resize_fifos: tells us it's ok to reconfigure our TxFIFO sizes.
* @setup_packet_pending: true when there's a Setup Packet in FIFO. Workaround
* @start_config_issued: true when StartConfig command has been issued
+ * @suspend_on_disconnect_quirk: set if core was configured with
+ * DWC_USB3_SUSPEND_ON_DISCONNECT_EN=1. Note that there's
+ * now way for software to detect this in runtime.
* @three_stage_setup: set if we perform a three phase setup
* @disable_scramble_quirk: set if we enable the disable scramble quirk
* @u2exit_lfps_quirk: set if we enable u2exit lfps quirk
@@ -818,6 +821,7 @@ struct dwc3 {
unsigned resize_fifos:1;
unsigned setup_packet_pending:1;
unsigned start_config_issued:1;
+ unsigned suspend_on_disconnect_quirk:1;
unsigned three_stage_setup:1;

unsigned disable_scramble_quirk:1;
diff --git a/drivers/usb/dwc3/host.c b/drivers/usb/dwc3/host.c
index 12bfd3c..9c42074 100644
--- a/drivers/usb/dwc3/host.c
+++ b/drivers/usb/dwc3/host.c
@@ -53,6 +53,10 @@ int dwc3_host_init(struct dwc3 *dwc)
pdata.usb3_lpm_capable = 1;
#endif

+ if ((dwc->revision < DWC3_REVISION_300A) &&
+ dwc->suspend_on_disconnect_quirk)
+ pdata.delay_portcsc_clear = 1;
+
ret = platform_device_add_data(xhci, &pdata, sizeof(pdata));
if (ret) {
dev_err(dwc->dev, "couldn't add platform data to xHCI device\n");
diff --git a/drivers/usb/dwc3/platform_data.h b/drivers/usb/dwc3/platform_data.h
index a3a3b6d..ebc8eb4 100644
--- a/drivers/usb/dwc3/platform_data.h
+++ b/drivers/usb/dwc3/platform_data.h
@@ -20,6 +20,13 @@
#include <linux/usb/ch9.h>
#include <linux/usb/otg.h>

+/**
+ * struct dwc3_platform_data - platform data of dwc3 controller
+ * @has_suspend_on_disconnect: true if core was configured with
+ * DWC_USB3_SUSPEND_ON_DISCONNECT_EN=1. Note that there's
+ * now way for software to detect this in runtime.
+ */
+
struct dwc3_platform_data {
enum usb_device_speed maximum_speed;
enum usb_dr_mode dr_mode;
@@ -32,6 +39,7 @@ struct dwc3_platform_data {

unsigned disable_scramble_quirk:1;
unsigned has_lpm_erratum:1;
+ unsigned has_suspend_on_disconnect:1;
unsigned u2exit_lfps_quirk:1;
unsigned u2ss_inp3_quirk:1;
unsigned req_p1p2p3_quirk:1;
--
1.7.9.5