[U-Boot] [PATCH v2] usbh/ehci: Increase timeout for enumeration

Vipin Kumar
2012-12-07T08:58:37Z

The current logic reads the port status just once after usb_hub_power_on and
expects the portstatus and portchange to report the connection status
immediately and correctly.

Few pen drives are not able to report both of them immediately ie. those pens
report the connection change but not the connected state after the first read.
This opportunity once lost is gone for ever because the u-boot, unlike linux or
any other OS, works in polling mode.

This patch modifies the logic to read the port status continuously until the
portstatus and portchange both report a connection change as well as a connected
state or no connection change and no connection. This logic is placed in a
timeout of 10 sec. At the end of it, the pen drive would have either reported a
ONE or a ZERO in bit 1 of portstatus as well as portchange.

It enhances the set of pen drives which can eventually be detected by u-boot

Signed-off-by: Vipin Kumar <vipin.kumar@st.com>
---
Hello Marek, Igor,

I found another way to handle it. Please let me know if it is OK from the USB
stack poit of view. The fact is that a few pens do not report a connected status
in portstatus while they report a connection change in portchange after a
usb_hub_power_on.

In this patch, I have tried to compare the connection bit from portstatus and
portchange for a timeout of 10 seconds. The situation is asumed to be stable
once both of them report the same. This seems to have increased the set of pens
supported by u-boot without any apparent side effect

Please let me know if this is OK from your side

Regards
Vipin

common/usb_hub.c | 25 ++++++++++++++++++++-----
1 file changed, 20 insertions(+), 5 deletions(-)

diff --git a/common/usb_hub.c b/common/usb_hub.c
index e4a1201..3a66b0e 100644
--- a/common/usb_hub.c
+++ b/common/usb_hub.c
@@ -396,14 +396,29 @@ static int usb_hub_configure(struct usb_device *dev)
for (i = 0; i < dev->maxchild; i++) {
ALLOC_CACHE_ALIGN_BUFFER(struct usb_port_status, portsts, 1);
unsigned short portstatus, portchange;
+ int ret;
+ ulong start = get_timer(0);
+
+ do {
+ ret = usb_get_port_status(dev, i + 1, portsts);
+ if (ret < 0) {
+ USB_HUB_PRINTF("get_port_status failed\n");
+ break;
+ }
+
+ portstatus = le16_to_cpu(portsts->wPortStatus);
+ portchange = le16_to_cpu(portsts->wPortChange);
+
+ if ((portchange & USB_PORT_STAT_C_CONNECTION) ==
+ (portstatus & USB_PORT_STAT_CONNECTION))
+ break;
+
+ mdelay(100);
+ } while (get_timer(start) < CONFIG_SYS_HZ * 10);

- if (usb_get_port_status(dev, i + 1, portsts) < 0) {
- USB_HUB_PRINTF("get_port_status failed\n");
+ if (ret < 0)
continue;
- }

- portstatus = le16_to_cpu(portsts->wPortStatus);
- portchange = le16_to_cpu(portsts->wPortChange);
USB_HUB_PRINTF("Port %d Status %X Change %X\n",
i + 1, portstatus, portchange);

--
1.8.0