Hi Kenta,
On Wed, Sep 13, 2023, Thinh Nguyen wrote:
> 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@xxxxxxxxxxxxxxx
> Fixes: e835c0a4e23c ("usb: dwc3: don't reset device side if dwc3 was configured as host-only")
> Reported-by: Kenta Sato <tosainu.maple@xxxxxxxxx>
> Closes: https://lore.kernel.org/linux-usb/ZPUciRLUcjDywMVS@xxxxxxxxx/
> Signed-off-by: Thinh Nguyen <Thinh.Nguyen@xxxxxxxxxxxx>
> ---
> drivers/usb/dwc3/core.c | 39 ++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 38 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
> index 9c6bf054f15d..343d2570189f 100644
> --- a/drivers/usb/dwc3/core.c
> +++ b/drivers/usb/dwc3/core.c
> @@ -279,9 +279,46 @@ int dwc3_core_soft_reset(struct dwc3 *dwc)
> * 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;
> reg &= ~DWC3_DCTL_RUN_STOP;
>
> base-commit: 0bb80ecc33a8fb5a682236443c1e740d5c917d1d
> --
> 2.38.1
Can you verify again using this updated patch? If it works, can you add
a Tested-by tag?
Thanks!
Thinh
