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Re: [Patch] [bug #26237] multiple problems with usb devices

From: Vladimir 'φ-coder/phcoder' Serbinenko
Subject: Re: [Patch] [bug #26237] multiple problems with usb devices
Date: Sun, 09 May 2010 15:50:04 +0200
User-agent: Mozilla-Thunderbird (X11/20091109)

Aleš Nesrsta wrote:
>>> Additionally, specification says that bit 31 (FIT) should be set to one
>>> if any change of FRAME_INTERVAL occurs - but I think it is necessary
>>> only if OHCI is in operational state - which is not in our case.
>> It can be done. Thanks.
> As I wrote, it is most probably not our case, (GRUB is setting controller
> in STOP state and nobody takes care about immediate impact of such
> setting,
> there are delays between set of FRAME_INTERVAL register and real
> start of first communication transaction) so don't hurry with such
> change...:-)
> (Because if you set FIT bit, you should also wait for FRT bit in register
> FRAME_REMAINING to be set by OHCI controller as the reaction.
> But it should happen in next start of frame, i.e. max. after 1ms.)
Ok, let's just keep it in mind but since it doesn't create any real
problems keep it the simple way.
>>   ...
>> I think the real problem are channels. I have suspicion that only first
>> channel of UHCI works. Another possible problem are the legacy support
>> bits in EHCI controller.
> It looks like good idea. I also told myself that I have to first
> discover how are
> GRUB modules usb and usbms working with USB ports of USB controller,
> how are they looking for connected USB mass storage device.
> So I try first to more study actual related source code.
> Another source of problem could be not only legacy support itself but
> EHCI set up made by BIOS. If I good understood leading part of EHCI
> specification, if EHCI is enabled - working, all USB 2.0 capable devices
> are not "seen" on UHCI/OHCI but on EHCI only. So, if BIOS enables EHCI
> to be working, none USB mass storage device will be reported on UHCI
> or OHCI ports. And all USB mass storage that I have are USB 2.0
> capable...
> If it is in this way, I don't see any simple way how to avoid it
> (maybe except
> disabling USB 2.0 support in BIOS if it is possible).
> But maybe it is my misunderstanding only.
Perhaps we can shutdown EHCI somehow? Do you know of reliable way to
completely reset all USB controllers?
Currently on Yeeloong ohci partially works but is able to retrieve
string only from webcam. I suppose that webcam wasn't used by pmon so
grub was able to assign an address to it itself. But maybe webcam is
simply on another controller (one of controller is Geode which differs a
bit from normal OHCI).
When I run grub without pmon detect_dev is correct but it's not possible
to send or receive anything and frame number stays 0xffff. I guess I
need to launch OHCI somehow.
> (If you will be find something sooner than me, inform me, please,
> thanks in advance.)
I also had to add old way of end detection because otherwise it hanged
Also in few places you had:
grub_le_to_cpu32 (&var)
instead of
grub_le_to_cpu32 (var)
> Best regards
> Ales
> _______________________________________________
> Grub-devel mailing list
> address@hidden

Vladimir 'φ-coder/phcoder' Serbinenko

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