Re: [PATCH v2] usb: dwc3: add disable u2mac linestate check quirk

From: Guenter Roeck
Date: Wed Apr 19 2017 - 01:16:06 EST

On Tue, Apr 18, 2017 at 8:59 PM, wlf <wulf@xxxxxxxxxxxxxx> wrote:
> Dear Guenter,
>
>
>
> å 2017å04æ18æ 21:18, Guenter Roeck åé:
>>
>> On Mon, Apr 17, 2017 at 10:17 PM, William Wu <william.wu@xxxxxxxxxxxxxx>
>> wrote:
>>>
>>> This patch adds a quirk to disable USB 2.0 MAC linestate check
>>> during HS transmit. Refer the dwc3 databook, we can use it for
>>> some special platforms if the linestate not reflect the expected
>>> line state(J) during transmission.
>>>
>>> When use this quirk, the controller implements a fixed 40-bit
>>> TxEndDelay after the packet is given on UTMI and ignores the
>>> linestate during the transmit of a token (during token-to-token
>>> and token-to-data IPGAP).
>>>
>>> On some rockchip platforms (e.g. rk3399), it requires to disable
>>> the u2mac linestate check to decrease the SSPLIT token to SETUP
>>> token inter-packet delay from 566ns to 466ns, and fix the issue
>>> that FS/LS devices not recognized if inserted through USB 3.0 HUB.
>>>
>>> Signed-off-by: William Wu <william.wu@xxxxxxxxxxxxxx>
>>> ---
>>> Changes in v2:
>>> - fix coding style
>>>
>>> Documentation/devicetree/bindings/usb/dwc3.txt | 2 ++
>>> drivers/usb/dwc3/core.c | 14 ++++++++++----
>>> drivers/usb/dwc3/core.h | 4 ++++
>>> 3 files changed, 16 insertions(+), 4 deletions(-)
>>>
>>> diff --git a/Documentation/devicetree/bindings/usb/dwc3.txt
>>> b/Documentation/devicetree/bindings/usb/dwc3.txt
>>> index f658f39..6a89f0c 100644
>>> --- a/Documentation/devicetree/bindings/usb/dwc3.txt
>>> +++ b/Documentation/devicetree/bindings/usb/dwc3.txt
>>> @@ -45,6 +45,8 @@ Optional properties:
>>> a free-running PHY clock.
>>> - snps,dis-del-phy-power-chg-quirk: when set core will change PHY
>>> power
>>> from P0 to P1/P2/P3 without delay.
>>> + - snps,tx-ipgap-linecheck-dis-quirk: when set, disable u2mac linestate
>>> check
>>> + during HS transmit.
>>
>> All other disable-something quirks are named
>> "snps,dis-something-quirk". Maybe use the same naming convention ?
>
> Yes, good ideaï I will fix it with "snps,dis-tx-ipgap-linecheck-quirk" in
> next patch verison.
> Thanks:-)
>>
>>
>>> - 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
>>> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
>>> index 455d89a..03429c5 100644
>>> --- a/drivers/usb/dwc3/core.c
>>> +++ b/drivers/usb/dwc3/core.c
>>> @@ -796,15 +796,19 @@ static int dwc3_core_init(struct dwc3 *dwc)
>>> dwc3_writel(dwc->regs, DWC3_GUCTL2, reg);
>>> }
>>>
>>> + reg = dwc3_readl(dwc->regs, DWC3_GUCTL1);
>>> +
>>
>> My understanding is that the register was only introduced with dwc3
>> revision 2.50a. Is it ok to read and write it unconditionally ?
>
> Yes, refer to dwc3 databook, the DWC3_GUCTL1 was introduced since 2.50a.
> Maybe it's better
> to read and write it only when we know our controller version.
>
> Is it good to fix it like the following patch?
> But this patch has a problem that we need to read and write the register
> twice if our controller verison > = 2.90a, and need this quirk.
>
> --- a/drivers/usb/dwc3/core.c
> +++ b/drivers/usb/dwc3/core.c
> @@ -806,6 +806,12 @@ static int dwc3_core_init(struct dwc3 *dwc)
> dwc3_writel(dwc->regs, DWC3_GUCTL1, reg);
> }
>
> + if (dwc->dis_tx_ipgap_linecheck_quirk) {
> + reg = dwc3_readl(dwc->regs, DWC3_GUCTL1);
> + reg |= DWC3_GUCTL1_TX_IPGAP_LINECHECK_DIS;
> + dwc3_writel(dwc->regs, DWC3_GUCTL1, reg);
> + }
> +
>

How about this ?

if (dwc->revision >= DWC3_REVISION_250A) {
reg = dwc3_readl(dwc->regs, DWC3_GUCTL1);
if (dwc->revision >= DWC3_REVISION_290A)
reg |= DWC3_GUCTL1_DEV_L1_EXIT_BY_HW;
if (dwc->dis_tx_ipgap_linecheck_quirk)
reg |= DWC3_GUCTL1_TX_IPGAP_LINECHECK_DIS;
dwc3_writel(dwc->regs, DWC3_GUCTL1, reg);
}

Thanks,
Guenter

> Hi John & Felipe,
> Could you provide me some suggestionï
> Thank youï
>
>>> /*
>>> * Enable hardware control of sending remote wakeup in HS when
>>> * the device is in the L1 state.
>>> */
>>> - if (dwc->revision >= DWC3_REVISION_290A) {
>>> - reg = dwc3_readl(dwc->regs, DWC3_GUCTL1);
>>> + if (dwc->revision >= DWC3_REVISION_290A)
>>> reg |= DWC3_GUCTL1_DEV_L1_EXIT_BY_HW;
>>> - dwc3_writel(dwc->regs, DWC3_GUCTL1, reg);
>>> - }
>>> +
>>> + if (dwc->tx_ipgap_linecheck_dis_quirk)
>>> + reg |= DWC3_GUCTL1_TX_IPGAP_LINECHECK_DIS;
>>> +
>>> + dwc3_writel(dwc->regs, DWC3_GUCTL1, reg);
>>>
>>> return 0;
>>>
>>> @@ -1023,6 +1027,8 @@ static void dwc3_get_properties(struct dwc3 *dwc)
>>> "snps,dis-u2-freeclk-exists-quirk");
>>> dwc->dis_del_phy_power_chg_quirk =
>>> device_property_read_bool(dev,
>>> "snps,dis-del-phy-power-chg-quirk");
>>> + dwc->tx_ipgap_linecheck_dis_quirk =
>>> device_property_read_bool(dev,
>>> + "snps,tx-ipgap-linecheck-dis-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 981c77f..3c2537b 100644
>>> --- a/drivers/usb/dwc3/core.h
>>> +++ b/drivers/usb/dwc3/core.h
>>> @@ -204,6 +204,7 @@
>>> #define DWC3_GCTL_DSBLCLKGTNG BIT(0)
>>>
>>> /* Global User Control 1 Register */
>>> +#define DWC3_GUCTL1_TX_IPGAP_LINECHECK_DIS BIT(28)
>>> #define DWC3_GUCTL1_DEV_L1_EXIT_BY_HW BIT(24)
>>>
>>> /* Global USB2 PHY Configuration Register */
>>> @@ -850,6 +851,8 @@ struct dwc3_scratchpad_array {
>>> * provide a free-running PHY clock.
>>> * @dis_del_phy_power_chg_quirk: set if we disable delay phy power
>>> * change quirk.
>>> + * @tx_ipgap_linecheck_dis_quirk: set if we disable u2mac linestate
>>> + * check during HS transmit.
>>> * @tx_de_emphasis_quirk: set if we enable Tx de-emphasis quirk
>>> * @tx_de_emphasis: Tx de-emphasis value
>>> * 0 - -6dB de-emphasis
>>> @@ -1004,6 +1007,7 @@ struct dwc3 {
>>> unsigned dis_rxdet_inp3_quirk:1;
>>> unsigned dis_u2_freeclk_exists_quirk:1;
>>> unsigned dis_del_phy_power_chg_quirk:1;
>>> + unsigned tx_ipgap_linecheck_dis_quirk:1;
>>>
>>> unsigned tx_de_emphasis_quirk:1;
>>> unsigned tx_de_emphasis:2;
>>> --
>>> 2.0.0
>>>
>>>
>>
>>
>
>