Messages in this thread | | | Date | Wed, 05 Nov 2014 09:48:49 +0000 | From | Ian Abbott <> | Subject | Re: [PATCH 0/2] staging: comedi: per-file read/write subdevice choice |
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On 04/11/2014 18:44, Hartley Sweeten wrote: > On Tuesday, November 04, 2014 11:09 AM, Ian Abbott wrote: >> This series of patches adds a couple of ioctl codes to the Comedi core >> to allow the current "read" and "write" subdevice to be changed after >> opening the comedi device. The current read and write subdevice >> information is stored in file private data allocated for the lifetime of >> the file object, so the notion of current "read" and "write" subdevice >> is local to the file object and does not alter anything in the main >> control structure for the comedi device. An extra level of indirection >> is now required to access the main control structure. >> >> I've tested the multiple "read" subdevice case using a modified version >> of the "comedi_test" module (modifying it to clone the existing AI >> subdevice), and a modified version of the "comedi_test" application >> (part of the "comedilib" installation) modified to use the new ioctls. >> There isn't any support in comedilib itself yet. >> >> 1) staging: comedi: prepare support for per-file read and write >> subdevices >> 2) staging: comedi: add ioctls to set per-file read and write subdevice >> >> drivers/staging/comedi/comedi.h | 2 + >> drivers/staging/comedi/comedi_compat32.c | 2 + >> drivers/staging/comedi/comedi_fops.c | 217 +++++++++++++++++++++++++++---- >> 3 files changed, 196 insertions(+), 25 deletions(-) > > Ian, > > If I understand this correctly, the user can now open the "comediX" > device which will give then access to the default dev->read_subdev > and dev->write_subdev. They can then use the new ioctls to change > the read/write subdevice and use them without having the open the > "comediX_subdY" devices. > > If this is correct it seems like a good idea.
That's correct.
> Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Thanks for the review!
> Also, does this mean we can get rid of comedi_alloc_subdevice_minor() > and the "comediX_sudbY" stuff?
That would be a bit premature at this stage. Maybe in a year or two.
-- -=( Ian Abbott @ MEV Ltd. E-mail: <abbotti@mev.co.uk> )=- -=( Web: http://www.mev.co.uk/ )=-
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