Messages in this thread |  | | | Date | Wed, 29 Sep 2004 15:16:01 +0100 | | From | Christoph Hellwig <> | | Subject | Re: New DRM driver model - gets rid of DRM() macros! |
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On Wed, Sep 29, 2004 at 03:12:03PM +0100, Keith Whitwell wrote: > Thinking about it, it may not have been a problem of crashing, but rather that > the behaviour visible from a program attempting to read (or poll) was > different with noop versions of these functions to NULL versions, and that was > causing problems. This is 18 months ago, so yes, I'm being vague. > > The X server does look at this file descriptor, which is where the problem > would have arisen, but only the gamma & maybe ffb drivers do anything with it.
Indeed, for read you're returning 0 now instead of the -EINVAL from common code when no ->read is present. I'd say the current drm behaviour is a bug, but if X drivers rely on it.
Similar in poll your return 0 now while the generic code return (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM) for fds without ->poll, and again I'd say current drm behaviour could be considered a bug. for ->flush there's no behaviour change of not supplying it.
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