From: Greg KH <greg@kroah.com>
To: Lucas Tanure <tanure@linux.com>
Cc: kernelnewbies@kernelnewbies.org
Subject: Re: request_firmware in DMA region
Date: Wed, 18 Mar 2020 18:09:37 +0100 [thread overview]
Message-ID: <20200318170937.GA3110553@kroah.com> (raw)
In-Reply-To: <52f381bd-d2cf-c109-6258-c73b06d4b113@linux.com>
On Wed, Mar 18, 2020 at 04:55:47PM +0000, Lucas Tanure wrote:
> On 2020-03-18 14:46, Greg KH wrote:
> > On Wed, Mar 18, 2020 at 02:29:24PM +0000, Lucas Tanure wrote:
> > > Hi,
> > >
> > > I'm sending firmware to usb device with this code:
> > > But it`s falling because the request firmware call didn't put my firmware in
> > > a DMA capable area. That's my guess.
> > >
> > > So how to request firmware in DMA capable area?
> > kmalloc your buffer used for USB transfers.
> Thanks, worked.
> >
> > Do you have a pointer to your driver anywhere? The code you show below
> > isn't in any kernel source that I can see.
>
> I`m working to get permission for that.
It will have to happen eventually, might as well do it now so that you
can get help with it :)
> Quick question: Why my usb driver doesn't unload after I disconnected it ?
Who knows, we can't see the code, odds are there is a bug somewhere.
> This driver is meant to load a new firmware into the board only. And after
> the bootloader finished the download the board with show it self with a
> different vendor and product id.
>
> All the firmware download in done in probe, so there is no need for this
> driver after that. Can my driver unload it self ?
Why do you need a kernel driver at all, you can do all of that from
userspace using libusb today.
And no, a driver can not unload itself, but it does not have to bind to
a device if you don't want to, which should keep it from ever actually
sticking to a device after the probe call has returned.
thanks,
greg k-h
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prev parent reply other threads:[~2020-03-18 17:10 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-18 14:29 request_firmware in DMA region Lucas Tanure
2020-03-18 14:46 ` Greg KH
2020-03-18 16:55 ` Lucas Tanure
2020-03-18 17:09 ` Greg KH [this message]
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