usb: dwc3: core: add support for disabling High-speed park mode

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.

Acked-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Signed-off-by: Stanley Chang <stanley_chang@realtek.com>
Link: https://lore.kernel.org/r/20230419020044.15475-1-stanley_chang@realtek.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index 435a4ad..0beaab9 100644 (file)
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -1198,6 +1198,9 @@ 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))
@@ -1509,6 +1512,8 @@ static void dwc3_get_properties(struct dwc3 *dwc)
                                "snps,ulpi-ext-vbus-drv");
        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 19490dc..d56457c 100644 (file)
--- 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 */
@@ -1104,6 +1105,8 @@ struct dwc3_scratchpad_array {
  *                     VBUS with an external supply.
  * @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                resume_hs_terminations:1;
        unsigned                ulpi_ext_vbus_drv: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;