[igt-dev] [PATCH i-g-t] tests/i915/i915_pm_dc: Changing sysfs open attribute to O_RDONLY

[Bhatt, Jigar]

-----Original Message-----
From: Latvala, Petri <petri.latvala at intel.com> 
Sent: Thursday, September 30, 2021 6:07 PM
To: Bhatt, Jigar <jigar.bhatt at intel.com>
Cc: igt-dev at lists.freedesktop.org; Varide, Nischal <nischal.varide at intel.com>
Subject: Re: [igt-dev] [PATCH i-g-t] tests/i915/i915_pm_dc: Changing sysfs open attribute to O_RDONLY

On Thu, Sep 30, 2021 at 05:50:50PM +0530, Jigar Bhatt wrote:
> Opening /sys/module/drm_kms_helper/parameters/ in read only mode to 
> avoid permission issue in dc9-dpms test.
> 
> Signed-off-by: Jigar Bhatt <jigar.bhatt at intel.com>
> ---
>  tests/i915/i915_pm_dc.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/tests/i915/i915_pm_dc.c b/tests/i915/i915_pm_dc.c index 
> d70ee060..4c9b871c 100644
> --- a/tests/i915/i915_pm_dc.c
> +++ b/tests/i915/i915_pm_dc.c
> @@ -419,7 +419,7 @@ static void setup_dc9_dpms(data_t *data, int 
> dc_target)  {
>  	int prev_dc, sysfs_fd;
>  
> -	igt_require((sysfs_fd = open(KMS_HELPER, O_RDWR)) >= 0);
> +	igt_require((sysfs_fd = open(KMS_HELPER, O_RDONLY)) >= 0);
>  	kms_poll_saved_state = igt_sysfs_get_boolean(sysfs_fd, "poll");
>  	igt_sysfs_set_boolean(sysfs_fd, "poll", KMS_POLL_DISABLE);
>  	close(sysfs_fd);
> @@ -449,7 +449,7 @@ static void kms_poll_state_restore(int sig)  {
>  	int sysfs_fd;
>  
> -	sysfs_fd = open(KMS_HELPER, O_WRONLY);
> +	sysfs_fd = open(KMS_HELPER, O_RDONLY);
>  	if (sysfs_fd >= 0) {
>  		igt_sysfs_set_boolean(sysfs_fd, "poll", kms_poll_saved_state);

Shouldn't this stay WRONLY?


--
Petri Latvala

Hi Petri,
Here since we are opening a directory, it needs to open as read-only.
This is the same scenario with other test cases too example,
igt_aux.c     igt_require((power_dir = open("/sys/power", O_RDONLY)) >= 0);


thanks and regards, 
Jigar Bhatt
>  		close(sysfs_fd);
> -- 
> 2.25.1
>