On Thu, Apr 13, 2023, Stanley Chang wrote:
> Setting the PARKMODE_DISABLE_HS bit in the DWC3_USB3_GUCTL1.
> When this bit is set to '1' all HS bus instances in park mode are disabled
>
> For some USB wifi devices, if enable this feature it will reduce the
> performance. Therefore, add an option for disabling HS park mode by
> device-tree.
>
> In Synopsys's dwc3 data book:
> In a few high speed devices when an IN request is sent within 900ns of the
> ACK of the previous packet, these devices send a NAK. When connected to
> these devices, if required, the software can disable the park mode if you
> see performance drop in your system. When park mode is disabled,
> pipelining of multiple packet is disabled and instead one packet at a time
> is requested by the scheduler. This allows up to 12 NAKs in a micro-frame
> and improves performance of these slow devices.
>
> Signed-off-by: Stanley Chang <stanley_chang@xxxxxxxxxxx>
> ---
> v2 to v3 change:
> 1. Add the comment message.
> 2. cc the right maintainers.
> ---
> 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 476b63618511..8fbc92a5f2cb 100644
> --- a/drivers/usb/dwc3/core.c
> +++ b/drivers/usb/dwc3/core.c
> @@ -1233,6 +1233,9 @@ static int dwc3_core_init(struct dwc3 *dwc)
> if (dwc->parkmode_disable_ss_quirk)
> reg |= DWC3_GUCTL1_PARKMODE_DISABLE_SS;
>
> + if (dwc->parkmode_disable_hs_quirk)
> + reg |= DWC3_GUCTL1_PARKMODE_DISABLE_HS;
> +
> if (DWC3_VER_IS_WITHIN(DWC3, 290A, ANY) &&
> (dwc->maximum_speed == USB_SPEED_HIGH ||
> dwc->maximum_speed == USB_SPEED_FULL))
> @@ -1555,6 +1558,8 @@ static void dwc3_get_properties(struct dwc3 *dwc)
> "snps,resume-hs-terminations");
> dwc->parkmode_disable_ss_quirk = device_property_read_bool(dev,
> "snps,parkmode-disable-ss-quirk");
> + dwc->parkmode_disable_hs_quirk = device_property_read_bool(dev,
> + "snps,parkmode-disable-hs-quirk");
> dwc->gfladj_refclk_lpm_sel = device_property_read_bool(dev,
> "snps,gfladj-refclk-lpm-sel-quirk");
>
> diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
> index 4743e918dcaf..30907ffcb3ec 100644
> --- a/drivers/usb/dwc3/core.h
> +++ b/drivers/usb/dwc3/core.h
> @@ -263,6 +263,7 @@
> #define DWC3_GUCTL1_DEV_FORCE_20_CLK_FOR_30_CLK BIT(26)
> #define DWC3_GUCTL1_DEV_L1_EXIT_BY_HW BIT(24)
> #define DWC3_GUCTL1_PARKMODE_DISABLE_SS BIT(17)
> +#define DWC3_GUCTL1_PARKMODE_DISABLE_HS BIT(16)
> #define DWC3_GUCTL1_RESUME_OPMODE_HS_HOST BIT(10)
>
> /* Global Status Register */
> @@ -1102,6 +1103,8 @@ struct dwc3_scratchpad_array {
> * generation after resume from suspend.
> * @parkmode_disable_ss_quirk: set if we need to disable all SuperSpeed
> * instances in park mode.
> + * @parkmode_disable_hs_quirk: set if we need to disable all HishSpeed
> + * 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
> @@ -1318,6 +1321,7 @@ struct dwc3 {
> unsigned dis_tx_ipgap_linecheck_quirk:1;
> unsigned resume_hs_terminations:1;
> unsigned parkmode_disable_ss_quirk:1;
> + unsigned parkmode_disable_hs_quirk:1;
> unsigned gfladj_refclk_lpm_sel:1;
>
> unsigned tx_de_emphasis_quirk:1;
> --
> 2.34.1
>
Acked-by: Thinh Nguyen <Thinh.Nguyen@xxxxxxxxxxxx>
Thanks,
Thinh
