[SeaBIOS] EHCI boot problems

Dave Frodin dave.frodin at se-eng.com
Tue Sep 9 21:15:04 CEST 2014

I'm seeing a problem booting from USB thumbdrives with commit ab9d771ce
    ehci: Update usb command timeouts to use usb_xfer_time()

I'm not quite sure what the problem is other than it not liking the new
I couldn't see any problems with the ehci_control() calls to ehci_wait_td().
But the ehci_send_bulk() only allows the system to boot if I change
    int ret = ehci_wait_td(pipe, td, end);
    int ret = ehci_wait_td(pipe, td, timer_calc(5000));

One potential problem is that the "end" value is calculated once and reused
multiple times in the functions. Prior to the commit the timeout value was
to the ehci_wait_td() function. Now the final "end" time is passed. So it
looks like
once the end timeout is reached in one of the loops that calls
ehci_wait_td() the
timer will always be expired for any other calls from that function.

One solution might be to get rid of the "end" variable and change the calls
    ret = ehci_wait_td(pipe, td, end);
    ret = ehci_wait_td(pipe, td, timer_calc(usb_xfer_time(p, datasize)));

Making the above change didn't have any impact on my booting problem until
I forced the ehci_send_bulk() timeouts to 5000.

Thanks in advance for any advice anyone can offer,
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