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Date: Tue, 19 May 2015 19:13:14 +0200
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From: Takashi Iwai <tiwai@suse.de>
To: Alan Stern <stern@rowland.harvard.edu>
Cc: Laura Abbott <labbott@redhat.com>,
	Marcel Holtmann <marcel@holtmann.org>,
	Laura Abbott <labbott@fedoraproject.org>,
	"Gustavo F. Padovan" <gustavo@padovan.org>,
	Johan Hedberg <johan.hedberg@gmail.com>,
	"David S. Miller" <davem@davemloft.net>,
	"bluez mailin list (linux-bluetooth@vger.kernel.org)" <linux-bluetooth@vger.kernel.org>,
	netdev <netdev@vger.kernel.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Ming Lei <ming.lei@canonical.com>,
	"Rafael J. Wysocki" <rafael.j.wysocki@intel.com>,
	<linux-usb@vger.kernel.org>
Subject: Re: [RESEND][PATCH] Bluetooth: Make request workqueue freezable
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	<Pine.LNX.4.44L0.1505191017460.1453-100000@iolanthe.rowland.org>
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At Tue, 19 May 2015 10:26:46 -0400 (EDT),
Alan Stern wrote:
> 
> > > >  Of just have request_firmware()
> > > > actually sleep until userspace is ready. Seriously, why is
> > > > request_firmware not just sleeping for us.
> 
> It won't work.  The request_firmware call is part of the probe 
> sequence, which in turn is part of the resume sequence.  Userspace 
> doesn't start running again until the resume sequence is finished.  If 
> request_firmware waited for userspace, it would hang.

Note that the recent request_firmware() doesn't need the user-space
invocation (unless the fallback is explicitly enabled) but loads the
file directly.  And, request_firmware() for the cached data is valid
to be called in the resume path.


Takashi