Re: 2.6.36/2.6.37: broken compatibility with userspace input-utils ?

[Dmitry Torokhov]

On Tue, Jan 25, 2011 at 12:07:29AM -0500, Mark Lord wrote:
> On 11-01-25 12:04 AM, Mark Lord wrote:
> > On 11-01-24 11:55 PM, Dmitry Torokhov wrote:
> >> On Mon, Jan 24, 2011 at 11:37:06PM -0500, Mark Lord wrote:
> > ..
> >>> This results in (map->size==10) for 2.6.36+ (wrong),
> >>> and a much larger map->size for 2.6.35 and earlier.
> >>>
> >>> So perhaps EVIOCGKEYCODE has changed?
> >>>
> >>
> >> So the utility expects that all devices have flat scancode space and
> >> driver might have changed so it does not recognize scancode 10 as valid
> >> scancode anymore.
> >>
> >> The options are:
> >>
> >> 1. Convert to EVIOCGKEYCODE2
> >> 2. Ignore errors from EVIOCGKEYCODE and go through all 65536 iterations.
> > 
> > or 3. Revert/fix the in-kernel regression.
> > 
> > The EVIOCGKEYCODE ioctl is supposed to return KEY_RESERVED for unmapped
> > (but value) keycodes, and only return -EINVAL when the keycode itself
> > is out of range.
> > 
> > That's how it worked in all kernels prior to 2.6.36,
> > and now it is broken.  It now returns -EINVAL for any unmapped keycode,
> > even though keycodes higher than that still have mappings.
> > 
> > This is a bug, a regression, and breaks userspace.
> > I haven't identified *where* in the kernel the breakage happened,
> > though.. that code confuses me.  :)
> 
> Note that this device DOES have "flat scancode space",
> and the kernel is now incorrectly signalling an error (-EINVAL)
> in response to a perfectly valid query of a VALID (and mappable)
> keycode on the remote control
> 
> The code really is a valid button, it just doesn't have a default mapping
> set by the kernel (I can set a mapping for that code from userspace and it works).
> 

OK, in this case let's ping Mauro - I think he done the adjustments to
IR keymap hanlding.

Thanks.

-- 
Dmitry
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