Messages in this thread | | | Date | Thu, 13 Nov 2008 20:15:13 -0800 | From | Greg KH <> | Subject | Re: [PATCH] Store the relevant miscdevice in file->private_data in misc_open() |
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On Thu, Nov 13, 2008 at 08:01:47PM -0800, Randy Dunlap wrote: > Greg KH wrote: > > On Fri, Nov 14, 2008 at 01:50:52PM +1100, Michael Ellerman wrote: > >> On Thu, 2008-11-13 at 16:18 -0800, Greg KH wrote: > >>> On Fri, Nov 14, 2008 at 10:54:41AM +1100, Michael Ellerman wrote: > >>>> On Thu, 2008-11-13 at 09:31 -0800, Greg KH wrote: > >>>>> On Thu, Nov 13, 2008 at 03:49:50PM +1100, Michael Ellerman wrote: > >>>>>> Currently it's not easy to share file_operations between multiple > >>>>>> instances of a miscdevice. In order to do this, the device code needs to > >>>>>> store a list of all it's miscdevice instances, and when fops->open() is > >>>>>> called, search the list and find the right device based on the minor > >>>>>> number. > >>>>>> > >>>>>> However the generic miscdevice code already has a list of miscdevices, > >>>>>> and uses this to find the right device in misc_open(). If misc_open() > >>>>>> would store the miscdevice it found in file->private_data, then the > >>>>>> device code wouldn't need to worry about storing it's own separate list > >>>>>> and searching that as well. > >>>>>> > >>>>>> The rest of the miscdevice code does not use file->private_data, so the > >>>>>> device code is still free to use file->private_data for something else > >>>>>> if it wants to. > >>>>>> > >>>>>> Signed-off-by: Michael Ellerman <michael@ellerman.id.au> > >>>>> Do you have a follow-on patch for some misc device using code that would > >>>>> take advantage of this change? > >>>> Ah, good point. I do, but not for upstream :/ > >>> Hm, then I have to ask why should we take this change? > >> Because it's seems like a good idea. > > > > You know we don't make changes to core code for drivers that aren't in > > the main tree, this is not a new thing... > > > >>> And why would the driver not be availble for upstream to take? > >> Because it's a hacky pile of crud, and it's for unreleased and > >> non-existent hardware. > > > > That's what the drivers/staging/ tree is for, send it on over to me and > > I'll add it to that location. > > for non-existent hardware?? that's not a good plan.
I read that as "not public yet" hardware. If that is incorrect, Randy is right, this isn't a good idea at all, sorry.
thanks,
greg k-h
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