@@ -222,6 +222,17 @@ static void __dwc3_set_mode(struct work_struct *work)
switch (desired_dr_role) {
case DWC3_GCTL_PRTCAP_HOST:
+ /*
+ * Setting GUCTL1 bit 29 so that controller
+ * will ignore single SE0 glitch on the linestate
+ * during transmit.
+ */
+ if (dwc->filter_se0_fsls_eop_quirk) {
+ reg = dwc3_readl(dwc->regs, DWC3_GUCTL1);
+ reg |= DWC3_GUCTL1_FILTER_SE0_FSLS_EOP;
+ dwc3_writel(dwc->regs, DWC3_GUCTL1, reg);
+ }
+
ret = dwc3_host_init(dwc);
if (ret) {
dev_err(dwc->dev, "failed to initialize host\n");
@@ -1788,6 +1799,8 @@ static void dwc3_get_properties(struct dwc3 *dwc)
dwc->tx_de_emphasis_quirk = device_property_read_bool(dev,
"snps,tx_de_emphasis_quirk");
+ dwc->filter_se0_fsls_eop_quirk = device_property_read_bool(dev,
+ "snps,filter-se0-fsls-eop-quirk");
device_property_read_u8(dev, "snps,tx_de_emphasis",
&tx_de_emphasis);
device_property_read_string(dev, "snps,hsphy_interface",
@@ -276,6 +276,7 @@
/* Global User Control 1 Register */
#define DWC3_GUCTL1_DEV_DECOUPLE_L1L2_EVT BIT(31)
+#define DWC3_GUCTL1_FILTER_SE0_FSLS_EOP BIT(29)
#define DWC3_GUCTL1_TX_IPGAP_LINECHECK_DIS BIT(28)
#define DWC3_GUCTL1_DEV_FORCE_20_CLK_FOR_30_CLK BIT(26)
#define DWC3_GUCTL1_DEV_L1_EXIT_BY_HW BIT(24)
@@ -1140,6 +1141,8 @@ struct dwc3_scratchpad_array {
* @gfladj_refclk_lpm_sel: set if we need to enable SOF/ITP counter
* running based on ref_clk
* @tx_de_emphasis_quirk: set if we enable Tx de-emphasis quirk
+ * @filter_se0_fsls_eop_quirk: set to ignores single
+ * SE0 glitch on the linestate during transmit.
* @tx_de_emphasis: Tx de-emphasis value
* 0 - -6dB de-emphasis
* 1 - -3.5dB de-emphasis
@@ -1373,6 +1376,7 @@ struct dwc3 {
unsigned gfladj_refclk_lpm_sel:1;
unsigned tx_de_emphasis_quirk:1;
+ unsigned filter_se0_fsls_eop_quirk:1;
unsigned tx_de_emphasis:2;
unsigned dis_metastability_quirk:1;
Currently in few of Qualcomm chips USB (Low speed) mouse not detected showing following errors: usb 1-1: Device not responding to setup address. usb 1-1: device not accepting address 2, error -71 usb 1-1: new low-speed USB device number 3 using xhci-hcd usb 1-1: Device not responding to setup address. usb 1-1: Device not responding to setup address. usb 1-1: device not accepting address 3, error -71 usb usb1-port1: attempt power cycle Based on the Logic analyzer waveforms, It has been identified that there is skew of about 8nS b/w DP & DM linestate signals (o/p of PHY & i/p to controller) at the UTMI interface, Due to this controller is seeing SE0 glitch condition, this is causing controller to pre-maturely assume that PHY has sent all the data & is initiating next packet much early, though in reality PHY is still busy sending previous packets. Enabling the GUCTL1.FILTER_SE0_FSLS_EOP bit29 allows the controller to ignore single SE0 glitches on the linestate during transmission. Only two or more SE0 signals are recognized as a valid EOP. When this feature is activated, SE0 signals on the linestate are validated over two consecutive UTMI/ULPI clock edges for EOP detection. Device mode (FS): If GUCTL1.FILTER_SE0_FSLS_EOP is set, then for device LPM handshake, the controller ignores single SE0 glitch on the linestate during transmit. Only two or more SE0 is considered as a valid EOP on FS port. Host mode (FS/LS): If GUCTL1.FILTER_SE0_FSLS_EOP is set, then the controller ignores single SE0 glitch on the linestate during transmit. Signed-off-by: Uttkarsh Aggarwal <quic_uaggarwa@quicinc.com> --- drivers/usb/dwc3/core.c | 13 +++++++++++++ drivers/usb/dwc3/core.h | 4 ++++ 2 files changed, 17 insertions(+)