Occasionally it was observed that on Intel MinnowMax board, with a USB 2.0 device connected to the bottom port, when doing 'usb start' on the xHCI controller:
scanning bus 0 for devices... cannot reset port 3!?
But neither of the two USB ports is routed to xHCI root port 3. Adding some debug information shows that xHCI port 3 PORTSC register mysteriously reports both CCS = 1 and CSC = 1.
This is not seen every time. After increasing the timeout to wait for power to become stable, the issue is gone. So this indicates current default USB power-on delay (20ms) might be at a critical region where power is stable/unstable. U-Boot provides a mechanism to have a environment variable to override the default one. Add one for MinnowMax.
Signed-off-by: Bin Meng bmeng.cn@gmail.com Reviewed-by: Simon Glass sjg@chromium.org Reviewed-by: Stefan Roese sr@denx.de Tested-by: Stefan Roese sr@denx.de ---
Changes in v4: None Changes in v3: None Changes in v2: None
include/configs/minnowmax.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/include/configs/minnowmax.h b/include/configs/minnowmax.h index ae95485..6ea607d 100644 --- a/include/configs/minnowmax.h +++ b/include/configs/minnowmax.h @@ -20,7 +20,8 @@
#define CONFIG_STD_DEVICES_SETTINGS "stdin=usbkbd,serial\0" \ "stdout=vidconsole,serial\0" \ - "stderr=vidconsole,serial\0" + "stderr=vidconsole,serial\0" \ + "usb_pgood_delay=40\0"
#define CONFIG_SCSI_DEV_LIST \ {PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_VALLEYVIEW_SATA}, \