Re: [PATCH v2 3/5] usb: dwc3: Add quirk for Synopsis device disconnection errata

Sneeker Yeh
2015-01-21T09:03:09Z

Hi Felipe:

Thanks for reviewing these,

2015-01-19 22:50 GMT+08:00 Felipe Balbi <balbi@ti.com>:
> Hi,
>
> On Mon, Jan 19, 2015 at 03:56:47PM +0800, Sneeker Yeh wrote:
>> 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 | 1 +
>> drivers/usb/dwc3/host.c | 4 ++++
>> drivers/usb/dwc3/platform_data.h | 1 +
>> 5 files changed, 29 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 8090249..d7458ff 100644
>> --- a/drivers/usb/dwc3/core.h
>> +++ b/drivers/usb/dwc3/core.h
>> @@ -832,6 +832,7 @@ struct dwc3 {
>>
>> unsigned tx_de_emphasis_quirk:1;
>> unsigned tx_de_emphasis:2;
>> + unsigned suspend_on_disconnect_quirk:1;
>
> you're missing the comment on the structure and these should be
> alphabetically sorted.

okay, I see, I'll change it like this:

--- 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..69562f1 100644
>> --- a/drivers/usb/dwc3/platform_data.h
>> +++ b/drivers/usb/dwc3/platform_data.h
>> @@ -44,4 +44,5 @@ struct dwc3_platform_data {
>>
>> unsigned tx_de_emphasis_quirk:1;
>> unsigned tx_de_emphasis:2;
>> + unsigned has_suspend_on_disconnect:1;
>
> needs a comment at the top of this structure and should sorted.

okay, I'll do it like this:

--- 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;

Much appreciate,
Sneeker

>
> --
> balbi