Messages in this thread | | | Date | Fri, 23 May 2008 13:20:50 +0100 | From | "Tom Spink" <> | Subject | Re: [PATCH 1/1] UIO: Add a write() function to enable/disable interrupts |
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2008/5/23 Hans J. Koch <hjk@linutronix.de>: > Am Fri, 23 May 2008 13:00:17 +0100 > schrieb "Tom Spink" <tspink@gmail.com>: > >> My initial idea was just a thought anyway, just to >> maintain a bit of extensibility if .write is ever needed for something >> else. :-) > > Hi Tom, > thanks for your contribution, but for me it's just the other way round: > I'm glad write() gets a defined purpose before people do something > stupid with it. It's good to remember that all data exchange with the > device has to be done through the mapped memory. If this is not > possible, the hardware is no candidate for a UIO driver. > > BTW, I wait for the first UIO driver which abuses this write() > function to write many different values to trigger different actions. > I wonder if I should restrict write() to the value 0 and 1... > > Thanks, > Hans
Hi Hans,
Thanks for your explanation. Another thing, I noticed then, is that in your return statement, you blindly return the the value of irqcontrol if it's non-zero, and if it's zero, then the length of the data written. However, if irqcontrol returns a value that's > 0, it could potentially confuse writers. I guess it's up to the implementer of irqcontrol to ensure they stick to -EXXX and 0, but it's just a thought (while you were on the subject of input validation!)
-- Tom Spink
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