[U-Boot] USB2.0 device timeout issue.

[Terry Zhou]

Hi all,
This is Terry from Marvell BSP team in ShangHai China.
We got one issue in USB like below:


1)      When reading large files(larger than 32M ) from USB2.0 u-disk, two of the disks got the timeout error like below:
Marvell>> fatload usb 0:1 0x1000000 got.mkv 0x2000000
reading got.mkv
EHCI timed out on TD - token=0x1e008d80
EHCI timed out on TD - token=0x1e008d80
EHCI timed out on TD - token=0x1e008d80
Error reading cluster
** Unable to read file got.mkv **

2)      I did some research on this issue and found that this issue disappear if we set "USB_MAX_XFER_BLK" to a smaller value.
/common/usb_storage.c
@@ -145,7 +145,7 @@ struct us_data {
  * limited to 65535 blocks.
  */
#elif defined(CONFIG_USB_EHCI)
-#define USB_MAX_XFER_BLK  65535
+#define USB_MAX_XFER_BLK  8000


3)      We also did some test in linux, it works in linux, we found that linux set the max_sectors to 240, and even we set them to a larger value,

The maximum value is 512, which is safe compares to the 8000 in Uboot.

Reference link for linux: http://www.linux-usb.org/FAQ.html#i5


4)      I found in Uboot forum, other guys met the same problem with us, see the link below:

https://lists.denx.de/pipermail/u-boot/2016-February/246405.html

and there is also some patches to find the optimal value of USB_MAX_XFER_BLK

https://www.mail-archive.com/u-boot@lists.denx.de/msg215952.html
But these patches have not been pushed to the mainline code.

Could you please share your ideas, why we didn't merge the patches and how should we fix this issue?
Thanks.

Best Regards,
Terry