usbh/ehci: Increase timeout for enumeration

PATCH Superseded Vipin Kumar 2 participants 3 messages Dec 13, 2012 – Dec 14, 2012

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Vipin Kumar

author

2012-12-13 10:55 UTC #0 lore raw

PATCH v3 1/1 usbh/ehci: Increase timeout for enumeration

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

Note: This 10 second timeout is based purely on several experiments done with the broken pen drives

Signed-off-by Vipin Kumar <[email protected]>

Acked-by Igor Grinberg <[email protected]>

---
Changes in v3
Added comment (in patch comment as well as code) for the reasons for choosing 10 seconds as timeout

 common/usb_hub.c | 33 ++++++++++++++++++++++++++++-----
 1 file changed, 28 insertions(+), 5 deletions(-)

common/usb_hub.c +28 -5

index e4a1201..4d75b90 100644
@@ -396,14 +396,37 @@ 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);
+
+		/*
+		 * Wait for (whichever finishes first)
+		 *  - A maximum of 10 seconds
+		 *    This is a purely observational value driven by connecting
+		 *    a few broken pen drives and taking the max * 1.5 approach
+		 *  - connection_change and connection state to report same
+		 *    state
+		 */
+		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);

Signature · 1 line

1.8.0

Marek Vasut

2012-12-13 13:11 UTC #1 lore raw

PATCH v3 1/1 usbh/ehci: Increase timeout for enumeration

Dear Vipin Kumar,

Quoted 16 lines

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.

Quoted 8 lines

It enhances the set of pen drives which can eventually be detected by u-boot
Note: This 10 second timeout is based purely on several experiments done with the broken pen drives
Signed-off-by Vipin Kumar <[email protected]>
Acked-by Igor Grinberg <[email protected]>

Applied, tested. Thanks

Best regards,
Marek Vasut

Vipin Kumar

author

2012-12-14 08:58 UTC #2 lore raw

PATCH v3 1/1 usbh/ehci: Increase timeout for enumeration

Quoted 21 lines · Marek Vasut

Dear Vipin Kumar,
Quoted 19 lines
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

Quoted 8 lines

Quoted 5 lines
Note: This 10 second timeout is based purely on several experiments done with the broken pen drives
Signed-off-by Vipin Kumar<[email protected]>
Acked-by Igor Grinberg<[email protected]>
Applied, tested. Thanks

Thanks Marek

Quoted 3 lines

Best regards,
Marek Vasut