> -----Original Message----- > From: Greg KH [mailto:greg@xxxxxxxxx] > Sent: Wednesday, July 06, 2011 11:02 AM > To: KY Srinivasan > Cc: gregkh@xxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; > devel@xxxxxxxxxxxxxxxxxxxxxx; virtualization@xxxxxxxxxxxxxx; Haiyang Zhang; Hank > Janssen > Subject: Re: [PATCH 15/77] Staging: hv: blkvsc: Add the appropriate > MODULE_ALIAS() line > > On Wed, Jul 06, 2011 at 02:55:12PM +0000, KY Srinivasan wrote: > > > > I think you mean MODULE_DEVICE_TABLE()? > > > > > > Yes, sorry for the typo. > > > > > > > I actually went down that path first > > > > adding code to file2alias.c for parsing the vmbus ID table. Given that this > > > approach > > > > would make it impossible to support auto-loading of these drivers > > > > on many of the released kernels, > > > > > > Wait, what? What is a "released kernel"? We are working on the > > > in-kernel patch, we don't care about older distros/releases for this > > > work at all. Also, it doesn't make sense at all, why would the change I > > > asked for make any difference on older distros/kernels? > > > > I understand we don't care here about older kernels and I will do what you > > have suggested. I just wanted to give you the rationale for choices I made: > > We are currently supporting older distros/kernels using these upstream bits. > > With the MODULE_ALIAS() approach, since I did not have to change any code > > outside the hv directory, this was possible. I was mostly concerned about > > having to make changes to code outside the hv directory and figuring out > > how to build and propagate these changes (file2alias.c) in older kernels. > > You create a patch like any other patch and give it to the people who > are stuck with those older kernels. It shouldn't be that hard, and it > also shouldn't be something that matters for this mainline work either. > > > > > I chose to go with the MODULE_ALIAS() macro that did not need any > > > > changes outside our drivers. In both methods, the formatting of the > > > > name is bus specific since I would be writing the code to parse the > > > > table in file2alias.c. > > > > > > Yes, that is what is needed to be done. > > > > > > > Granted, I have been quite unimaginative in my alias names, but I > > > > thought they were reasonably descriptive. If at all possible, for the > > > > reasons listed above, I would prefer to use the MODULE_ALIAS() macro > > > > (I could embed all or part of the guid in the alias). Let me know. > > > > > > Please do the correct thing and use MODULE_DEVICE_TABLE(). > > > > We have four drivers now excluding vmbus and soon we will have only three > > drivers with the merge of block and stor drivers. Would you still recommend I > use the > > full guid to name these drivers. > > Yes, why not? > > > Rather than embedding the entire 128bit guid in module aliases, I was > > thinking of setting up a more reasonable namespace for these drivers > > (like what virtio has done for instance). Let me know if this is ok > > with you if I took that route (mapping the guid to small integers and > > having these integers be used in alias strings). > > What's the big deal of having a large number as an alias? Is there some > constraint here that I am not aware of? It is certainly easier to deal with a small integer than with 128bit giud and there is no added benefit dealing with guids since the number of drivers we will support under vmbus will never exceed a very small number. Having said that, I will go ahead and embed full guids as you have suggested. So, the aliases for these drivers will be: vmbus:device guid. Regards, K. Y _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/devel
