[PATCH] usb: dwc2: use a longer core rest timeout in dwc2_core_reset()

From: Mathias Kresin
Date: Sun Jul 07 2019 - 10:22:24 EST


Testing on different generations of Lantiq MIPS SoC based boards, showed
that it takes up to 1500 us until the core reset bit is cleared.

The driver from the vendor SDK (ifxhcd) uses a 1 second timeout. Use the
same timeout to fix wrong hang detections and make the driver work for
Lantiq MIPS SoCs.

At least till kernel 4.14 the hanging reset only caused a warning but
the driver was probed successful. With kernel 4.19 errors out with
EBUSY.

Cc: linux-stable <stable@xxxxxxxxxxxxxxx> # 4.19+
Signed-off-by: Mathias Kresin <dev@xxxxxxxxx>
---
drivers/usb/dwc2/core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/usb/dwc2/core.c b/drivers/usb/dwc2/core.c
index 8b499d643461..01cdd236be99 100644
--- a/drivers/usb/dwc2/core.c
+++ b/drivers/usb/dwc2/core.c
@@ -524,7 +524,7 @@ int dwc2_core_reset(struct dwc2_hsotg *hsotg, bool skip_wait)
greset |= GRSTCTL_CSFTRST;
dwc2_writel(hsotg, greset, GRSTCTL);

- if (dwc2_hsotg_wait_bit_clear(hsotg, GRSTCTL, GRSTCTL_CSFTRST, 50)) {
+ if (dwc2_hsotg_wait_bit_clear(hsotg, GRSTCTL, GRSTCTL_CSFTRST, 10000)) {
dev_warn(hsotg->dev, "%s: HANG! Soft Reset timeout GRSTCTL GRSTCTL_CSFTRST\n",
__func__);
return -EBUSY;
--
2.17.1