4.19-stable review patch. If anyone has any objections, please let me know.
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From: Thinh Nguyen Thinh.Nguyen@synopsys.com
commit 8bea147dfdf823eaa8d3baeccc7aeb041b41944b upstream.
When there's phy initialization, we need to initiate a soft-reset sequence. That's done through USBCMD.HCRST in the xHCI driver and its initialization, However, the dwc3 driver may modify core configs before the soft-reset. This may result in some connection instability. So, ensure the phy is ready before the controller updates the GCTL.PRTCAPDIR or other settings by issuing phy soft-reset.
Note that some host-mode configurations may not expose device registers to initiate the controller soft-reset (via DCTL.CoreSftRst). So we reset through GUSB3PIPECTL and GUSB2PHYCFG instead.
Cc: stable@vger.kernel.org Fixes: e835c0a4e23c ("usb: dwc3: don't reset device side if dwc3 was configured as host-only") Reported-by: Kenta Sato tosainu.maple@gmail.com Closes: https://lore.kernel.org/linux-usb/ZPUciRLUcjDywMVS@debian.me/ Signed-off-by: Thinh Nguyen Thinh.Nguyen@synopsys.com Tested-by: Kenta Sato tosainu.maple@gmail.com Link: https://lore.kernel.org/r/70aea513215d273669152696cc02b20ddcdb6f1a.169456426... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/usb/dwc3/core.c | 39 ++++++++++++++++++++++++++++++++++++++- 1 file changed, 38 insertions(+), 1 deletion(-)
--- a/drivers/usb/dwc3/core.c +++ b/drivers/usb/dwc3/core.c @@ -244,9 +244,46 @@ static int dwc3_core_soft_reset(struct d * XHCI driver will reset the host block. If dwc3 was configured for * host-only mode or current role is host, then we can return early. */ - if (dwc->dr_mode == USB_DR_MODE_HOST || dwc->current_dr_role == DWC3_GCTL_PRTCAP_HOST) + if (dwc->current_dr_role == DWC3_GCTL_PRTCAP_HOST) return 0;
+ /* + * If the dr_mode is host and the dwc->current_dr_role is not the + * corresponding DWC3_GCTL_PRTCAP_HOST, then the dwc3_core_init_mode + * isn't executed yet. Ensure the phy is ready before the controller + * updates the GCTL.PRTCAPDIR or other settings by soft-resetting + * the phy. + * + * Note: GUSB3PIPECTL[n] and GUSB2PHYCFG[n] are port settings where n + * is port index. If this is a multiport host, then we need to reset + * all active ports. + */ + if (dwc->dr_mode == USB_DR_MODE_HOST) { + u32 usb3_port; + u32 usb2_port; + + usb3_port = dwc3_readl(dwc->regs, DWC3_GUSB3PIPECTL(0)); + usb3_port |= DWC3_GUSB3PIPECTL_PHYSOFTRST; + dwc3_writel(dwc->regs, DWC3_GUSB3PIPECTL(0), usb3_port); + + usb2_port = dwc3_readl(dwc->regs, DWC3_GUSB2PHYCFG(0)); + usb2_port |= DWC3_GUSB2PHYCFG_PHYSOFTRST; + dwc3_writel(dwc->regs, DWC3_GUSB2PHYCFG(0), usb2_port); + + /* Small delay for phy reset assertion */ + usleep_range(1000, 2000); + + usb3_port &= ~DWC3_GUSB3PIPECTL_PHYSOFTRST; + dwc3_writel(dwc->regs, DWC3_GUSB3PIPECTL(0), usb3_port); + + usb2_port &= ~DWC3_GUSB2PHYCFG_PHYSOFTRST; + dwc3_writel(dwc->regs, DWC3_GUSB2PHYCFG(0), usb2_port); + + /* Wait for clock synchronization */ + msleep(50); + return 0; + } + reg = dwc3_readl(dwc->regs, DWC3_DCTL); reg |= DWC3_DCTL_CSFTRST; dwc3_writel(dwc->regs, DWC3_DCTL, reg);