On Fri, Apr 13, 2012 at 09:26:14PM -0300, Eugeni Dodonov wrote: > On Fri, Apr 13, 2012 at 17:18, Chris Wilson <chris at chris-wilson.co.uk>wrote: > > > On Fri, 13 Apr 2012 17:08:41 -0300, Eugeni Dodonov < > > eugeni.dodonov at intel.com> wrote: > > > Prevent a NULL pointer exception when we are trying to retrieve EDID data > > > from non-existent adapter. > > > > This just means that a HDMI with a garbage ddc_bus is never detected. > > Since we control ddc_bus entirely, it means that the initialisation is > > completely bogus. Please fix the root cause and not paper over > > programming bugs. > > > > Sorry, I think I wasn't clear in my cover letter about this one.. I am not > hitting any issue with this current branch I sent; but the nature of the > code we have after the gmbus refactoring made me a bit paranoid about > accessing properties of something that could potential be NULL. > > As far as I can see, we should not hit this with any combination of outputs > on any hardware that is already covered by the wikipedia :). So I am fine > with dropping this patch if you also think that it does not adds anything > relevant to us. Or perhaps I should refactor it into adding some WARN's > instead? If you're uneasy about a NULL deref add a BUG_ON (because the NULL-deref will lead to an oops anyway) or add a WARN_ON and try to bail out. But if the condition is truely (or at least should be) impossible, a BUG_ON to document it is imo better (if we can't bail out in a sensible way). -Daniel -- Daniel Vetter Mail: daniel at ffwll.ch Mobile: +41 (0)79 365 57 48
