This fix addresses STAR 9001285599, which only affects DWC_usb3 version 3.20a. The timer value for PM_LC_TIMER in DWC_usb3 3.20a for the Link ECN changes is incorrect. If the PM TIMER ECN is enabled via GUCTL2[19], the link compliance test (TD7.21) may fail. If the ECN is not enabled (GUCTL2[19] = 0), the controller will use the old timer value (5us), which is still acceptable for the link compliance test. Therefore, clear GUCTL2[19] to pass the USB link compliance test: TD 7.21.

Cc: stable@vger.kernel.org Signed-off-by: Faisal Hassan quic_faisalh@quicinc.com Acked-by: Thinh Nguyen Thinh.Nguyen@synopsys.com --- Changes in v2: Updated comment and commit message to include the controller IP.

v1 link: https://lore.kernel.org/all/20240822084504.1355-1-quic_faisalh@quicinc.com

drivers/usb/dwc3/core.c | 15 +++++++++++++++ drivers/usb/dwc3/core.h | 2 ++ 2 files changed, 17 insertions(+)

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c index 734de2a8bd21..92d7ec830322 100644 --- a/drivers/usb/dwc3/core.c +++ b/drivers/usb/dwc3/core.c @@ -1378,6 +1378,21 @@ static int dwc3_core_init(struct dwc3 *dwc) dwc3_writel(dwc->regs, DWC3_GUCTL2, reg); }

+ /* + * STAR 9001285599: This issue affects DWC_usb3 version 3.20a + * only. If the PM TIMER ECM is enabled through GUCTL2[19], the + * link compliance test (TD7.21) may fail. If the ECN is not + * enabled (GUCTL2[19] = 0), the controller will use the old timer + * value (5us), which is still acceptable for the link compliance + * test. Therefore, do not enable PM TIMER ECM in 3.20a by + * setting GUCTL2[19] by default; instead, use GUCTL2[19] = 0. + */ + if (DWC3_VER_IS(DWC3, 320A)) { + reg = dwc3_readl(dwc->regs, DWC3_GUCTL2); + reg &= ~DWC3_GUCTL2_LC_TIMER; + dwc3_writel(dwc->regs, DWC3_GUCTL2, reg); + } + /* * When configured in HOST mode, after issuing U3/L2 exit controller * fails to send proper CRC checksum in CRC5 feild. Because of this diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h index 1e561fd8b86e..c71240e8f7c7 100644 --- a/drivers/usb/dwc3/core.h +++ b/drivers/usb/dwc3/core.h @@ -421,6 +421,7 @@

/* Global User Control Register 2 */ #define DWC3_GUCTL2_RST_ACTBITLATER BIT(14) +#define DWC3_GUCTL2_LC_TIMER BIT(19)

/* Global User Control Register 3 */ #define DWC3_GUCTL3_SPLITDISABLE BIT(14) @@ -1269,6 +1270,7 @@ struct dwc3 { #define DWC3_REVISION_290A 0x5533290a #define DWC3_REVISION_300A 0x5533300a #define DWC3_REVISION_310A 0x5533310a +#define DWC3_REVISION_320A 0x5533320a #define DWC3_REVISION_330A 0x5533330a

#define DWC31_REVISION_ANY 0x0