[Adding Martyn to Cc] [VME: devices not removed after commit 050c3d52cc7] On 13/01/2017 (Fri 11:03) Stefano Babic wrote:
> Hi, > > I have updated a custom VME device driver (mainly based on vme_user.c) > to 4.9 (previously it was for 3.14-). > > I see that VME device drivers cannot be loaded and unloaded due to this > commit: > > commit 050c3d52cc7810d9d17b8cd231708609af6876ae > Author: Paul Gortmaker <paul.gortma...@windriver.com> > Date: Sun Jul 3 14:05:56 2016 -0400 > > vme: make core vme support explicitly non-modular I've gone back and looked at this, and vme_user.c and I'm not yet 100% convinced this is the right conclusion. But perhaps, and I've put Martyn on the Cc, in the hopes that he can clarify as well, if needed. > > > In fact, this drops the remove function, that scans all devices attached > to the bus and call their remove function. So I guess my confusion here is between removal of a VME device, vs. the removal of a complete VME bus. The above commit you reference was based on the premise that removal of a VME bus is not supported. Which is not to say that a VME device removal is not supported. > > That means that "remove" entry points in VME device driver (let see in > drivers/staging/vme/devices/vme_user.c) are now dead code and the > required cleanup code is not called at all (devices and class are not > removed). Reloading the same driver cause errors due to the missing > cleanup by unloading. This does not let build VME device drivers as > module, as it is supposed to be done. Again, I don't think this analysis is 100% right, but I can't be sure because your driver is out of tree and I don't know what it does precisely. Looking at vme_user.c example, it has its own .remove function that should be executed at module unload, and that would do all the cleanup (see vme_user_remove). > > Paul, what do you mind ? For sure, we can restore the .remove and vme_bus_remove portions of that commit if it is a real regression against a correct use of the infrastructure, but I'm still not clear how you'd be triggering the vme_bus_remove unless the vme device driver was going up into its parent's bus struct directly. Maybe Martyn can spot where I've misunderstood the bus vs. device separation here. Paul. -- > > Best regards, > Stefano Babic > > > -- > ===================================================================== > DENX Software Engineering GmbH, Managing Director: Wolfgang Denk > HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany > Phone: +49-8142-66989-53 Fax: +49-8142-66989-80 Email: sba...@denx.de > =====================================================================
