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. DT patch will be sent separately. Changes in v2: Included bindings update for the quirk. Updated commit text for core patch. Link to v1: https://lore.kernel.org/all/20240823055642.27638-1-quic_uaggarwa@xxxxxxxxxxx/ Uttkarsh Aggarwal (2): dt-bindings: usb: snps,dwc3: Add snps,filter-se0-fsls-eop quirk usb: dwc3: core: Add support to ignore single SE0 glitches .../devicetree/bindings/usb/snps,dwc3.yaml | 6 ++++++ drivers/usb/dwc3/core.c | 13 +++++++++++++ drivers/usb/dwc3/core.h | 4 ++++ 3 files changed, 23 insertions(+) -- 2.17.1
