[Intel-gfx] [PATCH i-g-t v4 3/6] tests/kms_ccs: Prevent segfault if pipe is not supported

[Arkadiusz Hiler]

On Wed, Sep 27, 2017 at 03:34:16PM -0300, Gabriel Krisman Bertazi wrote:
> for_each_plane_on_pipe() indexes bad memory when iterating over an invalid
> pipe.  Make sure the pipe exists before trying to use it.  This prevents
> the crash below:
> 
> root at ideacentre:~# igt-gpu-tools/tests/kms_ccs --r pipe-D-crc-sprite-planes-basic
> IGT-Version: 1.19-g59f0e3d182a8 (x86_64) (Linux: 4.13.0-rc6.intel-boxes+x86_64)
> Received signal SIGSEGV.
> Stack trace:
>  #0 [fatal_sig_handler+0x185]
>  #1 [killpg+0x40]
>  #2 [__real_main485+0x2de]
>  #3 [main+0x3f]
>  #4 [__libc_start_main+0xf1]
>  #5 [_start+0x2a]
>  #6 [<unknown>+0x2a]
> Subtest pipe-D-crc-sprite-planes-basic: CRASH (0.004s)
> 
> Signed-off-by: Gabriel Krisman Bertazi <krisman at collabora.co.uk>
Reviewed-by: Arkadiusz Hiler <arkadiusz.hiler at intel.com>