[Mesa-dev] [PATCH 1/3] egl/x11: fix use of EGL_BAD_NATIVE_WINDOW

[Frank Binns]

On 31/07/15 12:53, Emil Velikov wrote:
> On 31 July 2015 at 11:02, Frank Binns <frank.binns at imgtec.com> wrote:
>> Commit 4ed23fd590 introduced some calls to _eglError inappropriately
>> passing it EGL_BAD_NATIVE_WINDOW. This was actually harmless in two of the
>> cases as _eglError gets called later on with a more appropriate error code
>> but (just to be safe) switch these to _eglLog calls instead. In the
>> remaining case, change the error to EGL_BAD_ALLOC instead as this seems
>> more appropriate.
>>
> Hmm... EGL_BAD_NATIVE_WINDOW might not be the best, but EGL_BAD_ALLOC
> doesn't seem much better.
>
> There is no memory allocation happening there, so I'm not sure why you
> believe it more appropriate. I'm wondering about EGL_BAD_PARAMETER,
> yet it's very unlikely we'll ever get here. Did you see any uses that
> trigger this ?
>
> -Emil
The errors available to us, i.e. the ones mentioned in the EGL spec, are:
- EGL_BAD_MATCH
- EGL_BAD_CONFIG
- EGL_BAD_NATIVE_WINDOW
- EGL_BAD_ALLOC

I believe there are two possible ways we can end up going down this path:
1) xcb_get_setup fails due to a previous error on the connection. The
error that appears most in the xcb code is XCB_CONN_CLOSED_MEM_INSUFFICIENT.

2) The 'rem' field of xcb_screen_iterator_t is 0.

In both cases EGL_BAD_ALLOC seems like the most appropriate error.

I've not actually hit this error path but spotted it when making the
fixes in patches 2 and 3.

Thanks
Frank