linux-kernel - Re: bluetooth related firmware loader spew on resume.

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Date:	Wed, 26 Nov 2014 15:16:35 +0100
From:	Oliver Neukum <oneukum@...e.de>
To:	Marcel Holtmann <marcel@...tmann.org>
Cc:	Takashi Iwai <tiwai@...e.de>, Dave Jones <davej@...hat.com>,
	Linux Kernel <linux-kernel@...r.kernel.org>,
	pgynther@...gle.com, linux-bluetooth@...r.kernel.org
Subject: Re: bluetooth related firmware loader spew on resume.

On Wed, 2014-11-26 at 23:05 +0900, Marcel Holtmann wrote:
> Hi Oliver,
> 
> >> In order to paper over this, we may also remember the failing firmware
> >> and avoid loading it.  This might be an easer way than the endless
> >> fight against UMH race...
> > 
> > 
> > the full fix would be to implement reset_resume() for btusb.
> > It seems to me that setup() should be split in two methods,
> > one to request the firmware from user space and the second
> > to transfer it to the device. reset_resume() would just need
> > to repeat the second operation.
> 
> so when you do hci_register_dev, then hdev->setup is only called once. I really mean only once per lifetime of the hci_dev. So you would need to unregister the hci_dev first before hdev->setup will ever be called again. So I am not sure this is actually the problem here. The problem here is entirely within request_firmware() unless of course we run through the USB probe handlers again. Which I do not see happening here.

It seems most likely to me that probing is indeed done again.
btusb does not implement reset_resume(). If power goes away
as is usual on S3/4 the device is reenumerated. The original
trace has a call to btusb_setup_bcm_patchram().
What else could be happening?

	Regards
		Oliver



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