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From: "Aleš Nesrsta" <starous@volny.cz>
To: The development of GNU GRUB <grub-devel@gnu.org>
Subject: Re: Missing USB devices.
Date: Sat, 31 Aug 2013 20:10:56 +0200	[thread overview]
Message-ID: <522231B0.8080106@volny.cz> (raw)
In-Reply-To: <BBCDB0B9B472124D9EED8CB900AA04CA1F91C35E@corpappl747.corp.saab.se>



28.8.2013 08:59, Melki Christian (consultant) wrote:
> I'm thinking of the EHCI hand-over. In the case of EHCI handover beeing successful within the timeout, you never clear the USBLEGCTLSTS register (SMI's). You do that in the other cases however. Why? I can not think of any case of a successful handover with SMI's still enabled. To what purpose? A buggy BIOS would maybe act upon such stuff? Maybe thats a case for lost devices etc?
Ok, I made a short look into Linux USB source code and I saw there is 
USBLEGCTLSTS register reset in any case.
(What is maybe more interesting, Linux driver DOES NOT handover on some 
(broken) devices, only reset SMI...)

So I prepared simple "SMI" patch (attached).

BR,
Ales


  reply	other threads:[~2013-08-31 18:11 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-08-07  8:16 Missing USB devices Melki Christian (consultant)
2013-08-07 16:11 ` Andrey Borzenkov
2013-08-08  7:22   ` Melki Christian (consultant)
2013-08-09 18:27     ` Aleš Nesrsta
2013-08-09 22:24       ` Aleš Nesrsta
2013-08-27 11:37         ` Melki Christian (consultant)
2013-08-27 20:21           ` Aleš Nesrsta
2013-08-27 21:38             ` Vladimir 'φ-coder/phcoder' Serbinenko
2013-08-30 22:07               ` Aleš Nesrsta
2013-09-02  7:01                 ` Melki Christian (consultant)
2013-09-02 21:33                   ` USB controller hand-back (original thread: Missing USB devices.) Aleš Nesrsta
2013-09-02 22:52                     ` Vladimir 'φ-coder/phcoder' Serbinenko
2013-09-03  6:52                     ` Melki Christian (consultant)
2013-08-28  6:59             ` Missing USB devices Melki Christian (consultant)
2013-08-31 18:10               ` Aleš Nesrsta [this message]
2013-08-31 18:14                 ` [PATCH] " Aleš Nesrsta
2013-08-31 21:12                   ` Aleš Nesrsta
2013-09-02  7:17                     ` Melki Christian (consultant)
2013-09-23 12:47                     ` Vladimir 'φ-coder/phcoder' Serbinenko
2013-09-23 18:38                       ` Aleš Nesrsta

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