From: Greg KH <gregkh@linuxfoundation.org>
To: George Nychis <gnychis@gmail.com>
Cc: linux-kernel@vger.kernel.org
Subject: Re: what determines how firmware is loaded? (Q. on request_firmware details)
Date: Mon, 23 Apr 2012 14:21:44 -0700 [thread overview]
Message-ID: <20120423212144.GA3378@kroah.com> (raw)
In-Reply-To: <CA+7oygfcQbOFdCFibTW0pqYQpcLwrqCM_jvKpr=GYFBMn9t3GQ@mail.gmail.com>
On Mon, Apr 23, 2012 at 04:18:56PM -0400, George Nychis wrote:
> Hi all,
>
> I notice in an older version of Ubuntu that when I plugin a USB
> wireless device its firmware is loaded via sysfs. For example, this
> would pop up in sysfs:
> /sys/devices/pci0000:00/0000:00:1d.7/usb2/2-1/compat_firmware/2-1/loading
How old are we talking about here? What version of the kernel?
> In newer versions, I'm now seeing that the firmware seems to be loaded
> directly via a Kernel thread that is spawned. It checks for the
> firmware in some firmware directory (e.g., /lib/firmware) and loads it
> to the device.
Yes.
> I see in documentation that one method is referred to as asynchronous.
> Is this the former or latter?
Depends on the device.
> Has the former method of loading firmware been removed as the default?
> Is there any way to request that the firmware load be done manually
> (the former method)?
Why? In the end, they do the same thing, right?
> It seems as though instead of calling request_firmware(), I could call
> _request_firmware() with "uevent" set to 0? This would force for
> former behavior?
>
> Does "nowait" also have to be 0? I don't quite understand the
> separation between uevent and nowait.
I don't understand the problem here, isn't the end-result the same?
What is wrong with newer kernels?
thanks,
greg k-h
next prev parent reply other threads:[~2012-04-23 21:21 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-04-23 20:18 what determines how firmware is loaded? (Q. on request_firmware details) George Nychis
2012-04-23 21:21 ` Greg KH [this message]
2012-04-23 21:28 ` George Nychis
2012-04-23 22:52 ` George Nychis
2012-04-23 22:56 ` Greg KH
2012-04-26 15:23 ` Mark Brown
2012-04-26 15:27 ` Greg KH
2012-04-26 15:48 ` Mark Brown
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