On 3/17/21 12:51 PM, João Loureiro wrote:

When `usb start` is called, the dwc2 driver will try to start every USB device as host first, even if it is explicitly configured as peripheral in the device tree, as the documentation explains (`dr_mode = "peripheral"`).

So to avoid an unwanted 15 seconds delay when initializing the usb (one second per channel = 1s x 15), this patch adds a check to the initialization, and will skip a host initialization of the device, when it is explicitly set as peripheral. The checking is already done similarly in the `drivers/usb/gadget/dwc2_udc_otg.c` driver.

An example device tree entry: &usb0 { compatible = "snps,dwc2"; status = "okay"; dr_mode = "peripheral"; };

+CC Lukasz.

The patch looks OK, except you need SoB line, see e.g. https://www.kernel.org/doc/html/v5.10/process/submitting-patches.html

When in doubt, git format-patch -1 -o /tmp the patch and then run ./scripts/checkpatch.pl /tmp/00*patch on it, this will tell you what to do.

Proposed patch below: diff --git a/drivers/usb/host/dwc2.c b/drivers/usb/host/dwc2.c index ec643e9f45..c6ade25f53 100644 --- a/drivers/usb/host/dwc2.c +++ b/drivers/usb/host/dwc2.c @@ -21,6 +21,7 @@ #include <asm/io.h> #include <dm/device_compat.h> #include <linux/delay.h> +#include <linux/usb/otg.h> #include <power/regulator.h> #include <reset.h>

@@ -1204,7 +1205,13 @@ static int dwc2_init_common(struct udevice *dev, struct dwc2_priv *priv) #endif

  dwc_otg_core_init(dev);

• dwc_otg_core_host_init(dev, regs);

• if (usb_get_dr_mode(dev_ofnode(dev)) == USB_DR_MODE_PERIPHERAL) {

•    dev_dbg(dev, "USB device %s dr_mode set to %d. Skipping host_init.\n",\
  

•        dev->name, usb_get_dr_mode(dev_ofnode(dev)));
  

• }

• else

•    dwc_otg_core_host_init(dev, regs);
  
  clrsetbits_le32(&regs->hprt0, DWC2_HPRT0_PRTENA |
          DWC2_HPRT0_PRTCONNDET | DWC2_HPRT0_PRTENCHNG |
  
  

---

Excuse me if I missed any detail; That's my first patch to u-boot.