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From: Peter Korsgaard <jacmet@sunsite•dk>
To: "Grant Likely" <grant.likely@secretlab•ca>
Cc: David Brownell <david-b@pacbell•net>,
	linuxppc-dev@ozlabs•org, linux-usb@vger•kernel.org
Subject: Re: [patch v4 0/4] Cypress c67x00 (EZ-Host/EZ-OTG) support
Date: Mon, 28 Jan 2008 22:01:30 +0100	[thread overview]
Message-ID: <87ir1dfyvp.fsf@macbook.be.48ers.dk> (raw)
In-Reply-To: <fa686aa40801281240s5af3272bg7953e6a3d6022531@mail.gmail.com> (Grant Likely's message of "Mon\, 28 Jan 2008 13\:40\:25 -0700")

>>>>> "Grant" == Grant Likely <grant.likely@secretlab•ca> writes:

Hi,

 Grant> I've now merged the driver into my tree and tested it.

 Grant> The good news is that using only one device node is absolutely
 Grant> no problem.  It works without error or complaint and sysfs
 Grant> looks sane.

Great.

 Grant> The bad news is that I discovered a race condition on
 Grant> initialization.  The problem is that IRQs are enabled before
 Grant> the SIEs are configured.  The interrupt handler is firing
 Grant> immediately and tries to get the status of each SIE.  Since
 Grant> the SIE probe has not yet occured, sie->dev is NULL and we get
 Grant> a kernel oops when c67x00_ll_get_siemsg() tries to dereference
 Grant> it.

Not so great. I unfortunately don't see it here.

 Grant> However, register_irq() cannot be easily moved to after the
 Grant> SIE probe because the current probe code depends on interrupts
 Grant> being enabled.  Below is an ugly workaround that solves the
 Grant> problem to me, but there is probably a better solution.

Wouldn't it be simpler to just add a if (sie->dev) check to
_ll_get_siemsg()? Or doesn't the hcd init properly reinitialize the
device?

-- 
Bye, Peter Korsgaard

  reply	other threads:[~2008-01-28 21:01 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-01-21 10:34 [patch v4 0/4] Cypress c67x00 (EZ-Host/EZ-OTG) support Peter Korsgaard
2008-01-21 10:34 ` [patch v4 1/4] USB: add Cypress c67x00 low level interface code Peter Korsgaard
2008-01-21 10:34 ` [patch v4 2/4] USB: add Cypress c67x00 OTG controller core driver Peter Korsgaard
2008-01-21 10:34 ` [patch v4 3/4] USB: add Cypress c67x00 OTG controller HCD driver Peter Korsgaard
2008-01-21 10:34 ` [patch v4 4/4] USB: add Cypress c67x00 OTG controller gadget driver Peter Korsgaard
2008-01-21 17:11 ` [patch v4 0/4] Cypress c67x00 (EZ-Host/EZ-OTG) support Grant Likely
2008-01-21 20:16   ` Peter Korsgaard
2008-01-21 20:51     ` David Brownell
2008-01-21 20:53       ` Grant Likely
2008-01-21 20:01 ` David Brownell
2008-01-21 20:14   ` Grant Likely
2008-01-21 21:13     ` Peter Korsgaard
2008-01-21 21:16     ` Peter Korsgaard
2008-01-23 17:12       ` Grant Likely
2008-01-23 17:53         ` David Brownell
2008-01-23 21:20           ` Peter Korsgaard
2008-01-28 20:40           ` Grant Likely
2008-01-28 21:01             ` Peter Korsgaard [this message]
2008-01-23 21:18         ` Peter Korsgaard
2008-01-21 21:08   ` Peter Korsgaard

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