From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Brownell Subject: Re: [RFC / PATCH] [SPI] get_module while using it. Date: Tue, 15 Apr 2008 11:09:43 -0700 Message-ID: <200804151109.43278.david-b@pacbell.net> References: <20080414194549.GA1363@www.tglx.de> <200804141623.36838.david-b@pacbell.net> <20080415070723.GA18303@www.tglx.de> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: Sebastian Siewior To: spi-devel-general-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Return-path: In-Reply-To: <20080415070723.GA18303-Hfxr4Dq0UpYb1SvskN2V4Q@public.gmane.org> Content-Disposition: inline List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: spi-devel-general-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Errors-To: spi-devel-general-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: linux-spi.vger.kernel.org On Tuesday 15 April 2008, Sebastian Siewior wrote: > * David Brownell | 2008-04-14 16:23:36 [-0700]: > > >On Monday 14 April 2008, Sebastian Siewior wrote: > >> Without this it is possible to unload the SPI-driver while an > >> spidev user open()ed the spidev device. > > > >Does that misbehave in any way? That sort of unloading of > > Yes. Unload, read() -> Ooops. What's the oops, and with which controller driver? If the adapter is unloaded it's *supposed* to first complete all pending transfers (and prevent submission of new ones). And removing the subsidiary devices is supposed to unbind them ... though looking at it quickly, I suspect that the "spidev" driver doesn't check for unbound devices in its various I/O paths. So this sounds like a bug in the controller driver, or else in how spidev handles unbind. - Dave > >adapter code is possible with USB and I2C and hasn't been > >perceived as much of a problem. I'm not sure I see a strong > >reason for SPI to act very different. > > True. usb returns with -ENODEV after read/whatever. We could add > something like this to spi/spidev. This might also fit better into > hot-plugging. ------------------------------------------------------------------------- This SF.net email is sponsored by the 2008 JavaOne(SM) Conference Don't miss this year's exciting event. There's still time to save $100. Use priority code J8TL2D2. http://ad.doubleclick.net/clk;198757673;13503038;p?http://java.sun.com/javaone