[igt-dev] [PATCH i-g-t] tools/intel_gpu_frequency: fix device opening

[Zbigniew Kempczyński]

On Mon, Oct 16, 2023 at 03:17:52PM +0200, Kamil Konieczny wrote:
> High-level device open cleans device cache before running a test
> by using debugfs. This may be a problem when using a tool to
> change GPU frequency as there are systems with debugfs turned off
> or protected, as seen in bug report:
> 
> (intel_gpu_frequency:14896) igt_debugfs-CRITICAL: Test assertion failure function igt_drop_caches_set, file ../lib/igt_debugfs.c:1142:
> 
> [ 3553.930373] Lockdown: intel_gpu_frequ: debugfs access is restricted; see man kernel_lockdown.7
> none [integrity] confidentiality
> 
> intel_gpu_frequency is the tool, not a test, so fixed this by
> using more suitable device opening function.
> 
> Closes: https://gitlab.freedesktop.org/drm/igt-gpu-tools/-/issues/146
> Cc: Tvrtko Ursulin <tvrtko.ursulin at linux.intel.com>
> Signed-off-by: Kamil Konieczny <kamil.konieczny at linux.intel.com>
> ---
>  tools/intel_gpu_frequency.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/tools/intel_gpu_frequency.c b/tools/intel_gpu_frequency.c
> index 3ed331ab4..de0c6ddba 100644
> --- a/tools/intel_gpu_frequency.c
> +++ b/tools/intel_gpu_frequency.c
> @@ -283,7 +283,7 @@ int main(int argc, char *argv[])
>  	bool write, fail, targets[MAX+1] = {false};
>  	int i, fd, try = 1, set_freq[MAX+1] = {0};
>  
> -	fd = drm_open_driver(DRIVER_INTEL);
> +	fd = __drm_open_driver(DRIVER_INTEL);
>  	devid = intel_get_drm_devid(fd);
>  	device = igt_device_get_card_index(fd);
>  	close(fd);

Ok. Makes sense for me. I see no reason to call drop caches
path on process exit.

Reviewed-by: Zbigniew Kempczyński <zbigniew.kempczynski at intel.com>

--
Zbigniew

> -- 
> 2.42.0
>