Messages in this thread | | | Date | Wed, 15 Jan 2014 18:30:40 -0800 | From | Greg KH <> | Subject | Re: [PATCH v4] Staging: comedi: convert while loop to timeout in ni_mio_common.c |
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On Wed, Jan 15, 2014 at 06:29:21PM +0000, Hartley Sweeten wrote: > On Tuesday, January 14, 2014 8:59 PM, Greg KH wrote: > > Sleep for at least 10, as I think that's the smallest time delay you can > > sleep for anyway (meaning it will be that long no matter what number you > > put there less than 10, depending on the hardware used of course.) > > A bit off topic here but I have a somewhat related question about timeouts. > > There are a number of comedi drivers that do a "wait for end-of-conversion" > as part of the (*insn_read) for an analog input subdevice or (*insn_write) for > an analog output subdevice. These functions return an errno if a timeout occurs. > > Currently either -ETIME or -ETIMEDOUT is returned. This errno ends up getting > returned to the user as the result of the unlocked_ioctl file operation. What is > the more appropriate errno? Or is there is better one that should be used?
I think they should all be -ETIMEDOUT, -ETIME is used for something else, and shouldn't be sent to userspace as I don't think it knows what to do with it.
thanks,
greg k-h
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