On Mon, 26 Nov 2007 13:39:41 -0800 (PST) Aaron Young <[EMAIL PROTECTED]> wrote:
> > > Konstantin, some comments: > > 3. Why can't you use the HID URB? Locking? Using the HID URB seems > to work fine for OHCI and EHCI. This is the reason that > seems to cause so much complication in your code. Back > in the 2.4 timeframe, Intel did a UHCI KDB implementation > that used the HID URB. Perhaps it would be useful to dig up that > old code and compare it? I can possibly pass that code on to you > if you want... > > Also, does enqueing two URBs for the same device cause any > problems (is it "legal")? > > > -Aaron > > I explained it earlier: http://oss.sgi.com/archives/kdb/2007-11/msg00003.html KDB Poll driver should not depend on USB kernel code because (in case when KDB driver uses the same code with kernel USB driver) if CPU0 executes kernel USB driver and, in the same time, CPU1 hits breakpoint, CPU0 would be frozen in kernel USB driver. USB spinlocks would be locked by CPU0, so KDB USB code couldn't get lock and deadlock would occur. Or, if we don't use lock, kernel USB driver data can't be corrupted. --------------------------- Use http://oss.sgi.com/ecartis to modify your settings or to unsubscribe.
