Re: [igt-dev] [PATCH i-g-t v2 2/2] tests/i915/i915_pm_dc: Fix DC9 test

["Gupta, Anshuman" <anshuman.gupta@intel.com>]

> -----Original Message-----
> From: Bhatt, Jigar <jigar.bhatt@intel.com>
> Sent: Wednesday, September 22, 2021 11:23 AM
> To: igt-dev@lists.freedesktop.org
> Cc: Bhatt, Jigar <jigar.bhatt@intel.com>; Gupta, Anshuman
> <anshuman.gupta@intel.com>; Varide, Nischal <nischal.varide@intel.com>;
> Shankar, Uma <uma.shankar@intel.com>; Sharma, Swati2
> <swati2.sharma@intel.com>
> Subject: [PATCH i-g-t v2 2/2] tests/i915/i915_pm_dc: Fix DC9 test
> 
> V1:
> Currently, check_dc9 is being called with reference
> (previous) counter being read after dpms_off call.
> At this time, already the counter is 0.
> We need to read the counter before dpms_off is called so that it holds the
> previous value which had incremented while testing shallow states (DC5 or DC6).
> 
> V2:
> Bit cleaner code.[Imre]
> dump the i915_pm_runtime_status debugfs file in case of test
> failure.[Anshuman]
> 
> V3:
> Disabling the polling during DC9 test “echo 0 >
> /sys/module/drm_kms_helper/parameters/poll”.[Anshuman]
> 
> V4:
> passing right fd to igt_sysfs_get_boolean() function, moving save and get part of
> polling to setup_dc9_dpms().
> 
> Signed-off-by: Jigar Bhatt <jigar.bhatt@intel.com>
> ---
>  tests/i915/i915_pm_dc.c | 45 ++++++++++++++++++++++++++++-------------
>  1 file changed, 31 insertions(+), 14 deletions(-)
> 
> diff --git a/tests/i915/i915_pm_dc.c b/tests/i915/i915_pm_dc.c index
> 04acf839..4efe3206 100644
> --- a/tests/i915/i915_pm_dc.c
> +++ b/tests/i915/i915_pm_dc.c
> @@ -40,6 +40,7 @@
>  #define CHECK_DC3CO	(1 << 2)
> 
>  #define PWR_DOMAIN_INFO "i915_power_domain_info"
> +#define RPM_STATUS "i915_runtime_pm_status"
> 
>  typedef struct {
>  	double r, g, b;
> @@ -393,42 +394,58 @@ static bool support_dc6(int debugfs_fd)
>  	return strstr(buf, "DC5 -> DC6 count");  }
> 
> -static bool check_dc9(uint32_t debugfs_fd, int prev_dc, bool dc6_supported,
> int seconds)
> +static bool dc9_wait_entry(uint32_t debugfs_fd, int dc_target, int
> +prev_dc, int seconds)
>  {
>  	/*
>  	 * since we do not have DC9 counter,
>  	 * so we rely on dc5/dc6 counter reset to check if display engine was in
> DC9.
>  	 */
> -	return igt_wait(dc6_supported ? read_dc_counter(debugfs_fd,
> CHECK_DC6) <
> -			prev_dc : read_dc_counter(debugfs_fd, CHECK_DC5) <
> +	return igt_wait(read_dc_counter(debugfs_fd, dc_target) >
>  			prev_dc, seconds, 100);
>  }
> 
> -static void setup_dc9_dpms(data_t *data, int prev_dc, bool dc6_supported)
> +static void check_dc9(data_t *data, int dc_target, int prev_dc)
>  {
> +	igt_assert_f(dc9_wait_entry(data->debugfs_fd, dc_target, prev_dc,
> 3000),
> +			"DC9 state is not achieved\n%s:\n%s\n", RPM_STATUS,
> +			data->debugfs_dump = igt_sysfs_get(data-
> >debugfs_fd, RPM_STATUS)); }
> +
> +static bool setup_dc9_dpms(data_t *data, int dc_target, int sysfs_fd,
> +const char *kms_poll) {
> +	int prev_dc;
> +	bool buf = true;
> +
> +	if (sysfs_fd >= 0) {
> +		buf = igt_sysfs_get_boolean(sysfs_fd, kms_poll);
> +		igt_sysfs_set_boolean(sysfs_fd, kms_poll, 0);
> +	}
> +	prev_dc = read_dc_counter(data->debugfs_fd, dc_target);
>  	setup_dc_dpms(data);
>  	dpms_off(data);
> -	igt_skip_on_f(!(igt_wait(dc6_supported ? read_dc_counter(data-
> >debugfs_fd, CHECK_DC6) >
> -				prev_dc : read_dc_counter(data->debugfs_fd,
> CHECK_DC5) >
> +	igt_skip_on_f(!(igt_wait(read_dc_counter(data->debugfs_fd, dc_target)
> +>
>  				prev_dc, 3000, 100)), "Unable to enters shallow
> DC states\n");
>  	dpms_on(data);
>  	cleanup_dc_dpms(data);
> +	return buf;
>  }
> 
>  static void test_dc9_dpms(data_t *data)  {
> -	bool dc6_supported;
> +	int prev_dc, dc_target, sysfs_fd;
> +	bool buf;
> +	const char *kms_poll =
> "/sys/module/drm_kms_helper/parameters/poll";
Better to use macro for path string.
> 
> +	sysfs_fd = open(kms_poll, O_WRONLY);
Error condition need to be check for open.
>  	require_dc_counter(data->debugfs_fd, CHECK_DC5);
> -	dc6_supported = support_dc6(data->debugfs_fd);
> -	setup_dc9_dpms(data, dc6_supported ? read_dc_counter(data-
> >debugfs_fd, CHECK_DC6) :
> -			read_dc_counter(data->debugfs_fd, CHECK_DC5),
> dc6_supported);
> +	dc_target = support_dc6(data->debugfs_fd) ? CHECK_DC6 :
> CHECK_DC5;
> +	buf = setup_dc9_dpms(data, dc_target, sysfs_fd, kms_poll);
> +	prev_dc = read_dc_counter(data->debugfs_fd, dc_target);
>  	dpms_off(data);
> -	igt_assert_f(check_dc9(data->debugfs_fd, dc6_supported ?
> -				read_dc_counter(data->debugfs_fd,
> CHECK_DC6) :
> -				read_dc_counter(data->debugfs_fd,
> CHECK_DC5),
> -				dc6_supported, 3000), "Not in DC9\n");
> +	check_dc9(data, dc_target, prev_dc);
>  	dpms_on(data);
> +	if (sysfs_fd >= 0)
> +		igt_sysfs_set_boolean(sysfs_fd, kms_poll, buf);
This need to restore in an igt exit hander, when test will fail control flow will not reach here and
It will not restore the value.
Check igt_install_exit_handler().
Br,
Anshuman Gupta.

>  }
> 
>  IGT_TEST_DESCRIPTION("These tests validate Display Power DC states");
> --
> 2.25.1