[Intel-gfx] [PATCH v4 i-g-t] tests/kms: increase max threshold time for edid read

[Lofstedt, Marta]

> -----Original Message-----
> From: Taylor, Clinton A
> Sent: Thursday, August 10, 2017 8:50 PM
> To: intel-gfx at lists.freedesktop.org
> Cc: Taylor, Clinton A <clinton.a.taylor at intel.com>; Vetter, Daniel
> <daniel.vetter at intel.com>; Lofstedt, Marta <marta.lofstedt at intel.com>
> Subject: [PATCH v4 i-g-t] tests/kms: increase max threshold time for edid
> read
> 
> From: Clint Taylor <clinton.a.taylor at intel.com>
> 
> Current 50ms max threshold timing for an EDID read is very close to the
> actual time for a 2 block HDMI EDID read. Adjust the timings base on
> connector type as DP reads are at 1 MBit and HDMI at 100K bit. If an LSPcon is
> connected to device under test the -l option should be passed to update the
> threshold timing to allow the LSPcon to read the EDID at the HDMI timing.
> The -l option should be used when LSPcon is on the motherboard or if a
> USB_C->HDMI converter is present
> 
> V2: Adjust timings based on connector type, EDID size, and Add an option to
> specify if an LSPcon is present.
> V3: Add bugzilla to commit message
> V4: remove edid_size check from HDMI multiplier. Fixes DVI on HDMI.
> 
> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=100047
> 
> Cc: Daniel Vetter <daniel.vetter at intel.com>
> Cc: Marta Lofstedt <marta.lofstedt at intel.com>
> Signed-off-by: Clint Taylor <clinton.a.taylor at intel.com>
> ---
>  tests/kms_sysfs_edid_timing.c | 74
> +++++++++++++++++++++++++++++++++++--------
>  1 file changed, 60 insertions(+), 14 deletions(-)
> 
> diff --git a/tests/kms_sysfs_edid_timing.c b/tests/kms_sysfs_edid_timing.c
> index 1201388..0382610 100644
> --- a/tests/kms_sysfs_edid_timing.c
> +++ b/tests/kms_sysfs_edid_timing.c
> @@ -26,21 +26,46 @@
>  #include <fcntl.h>
>  #include <sys/stat.h>
> 
> -#define THRESHOLD_PER_CONNECTOR	10
> -#define THRESHOLD_TOTAL		50
> -#define CHECK_TIMES		15
> +#define THRESHOLD_FOR_EMPTY_CONNECTOR	10
> +#define THRESHOLD_PER_EDID_BLOCK		5
> +#define HDMI_THRESHOLD_MULTIPLIER		10
> +#define CHECK_TIMES				10
> 
>  IGT_TEST_DESCRIPTION("This check the time we take to read the content of
> all "
>  		     "the possible connectors. Without the edid -
> ENXIO patch "
> 
> "(http://permalink.gmane.org/gmane.comp.video.dri.devel/62083), "
> -		     "we sometimes take a *really* long time. "
> -		     "So let's just check for some reasonable
> timing here");
> +		     "we sometimes take a *really* long time. So
> let's check "
> +		     "an approximate time per edid block based on
> connector "
> +		     "type. The -l option adjusts DP timing to
> reflect HDMI read "
> +		     "timings from LSPcon.");
> +
> +/* The -l option has been added to correctly handle timings when an
> +LSPcon is
> + * present. This could be on the platform itself or in a USB_C->HDMI
> converter.
> + * With LSPCon EDID read timing will need to change from the 1 Mbit AUX
> + * bus speed to the 100 Kbit HDMI DDC bus speed  */ bool
> +lspcon_present;
> 
> +static int opt_handler(int opt, int opt_index, void *data) {
> +	if (opt == 'l') {
> +		lspcon_present = true;
> +		igt_info("set LSPcon present on DP ports\n");
> +	}
> 
> -igt_simple_main
> +	return 0;
> +}
> +
> +int main(int argc, char **argv)
>  {
>  	DIR *dirp;
>  	struct dirent *de;
> +	lspcon_present = false;
> +
> +	igt_simple_init_parse_opts(&argc, argv, "l", NULL, NULL,
> +				      opt_handler,
> NULL);

We can't have this lspcon as an argument to the test, it will not work with automated testing using piglit as we do for CI. 
Theoretically we could add a "has_lspcon" to debugfs, but I believe that this test has started to be over complicated.
The intention of the test is to do a sanity check so that we don't drift off here, so I actually prefer the V1.
Your detailed work could however be used in a benchmark, where the result would be the actually timing, I am sure there is a performance team who would like that.

/Marta

> +
> +	igt_skip_on_simulation();
> 
>  	dirp = opendir("/sys/class/drm");
>  	igt_assert(dirp != NULL);
> @@ -49,17 +74,34 @@ igt_simple_main
>  		struct igt_mean mean = {};
>  		struct stat st;
>  		char path[PATH_MAX];
> -		int i;
> +		char edid_path[PATH_MAX];
> +		char edid[512]; /* enough for 4 block edid */
> +		unsigned long edid_size = 0;
> +		int i, fd_edid;
> +		unsigned int threshold = 0;
> 
>  		if (*de->d_name == '.')
>  			continue;;
> 
>  		snprintf(path, sizeof(path),
> "/sys/class/drm/%s/status",
>  				de->d_name);
> +		snprintf(edid_path, sizeof(edid_path),
> "/sys/class/drm/%s/edid",
> +				de->d_name);
> 
>  		if (stat(path, &st))
>  			continue;
> 
> +		fd_edid = open(edid_path, O_RDONLY);
> +		if (fd_edid == -1) {
> +			igt_warn("Read Error EDID\n");
> +			continue;
> +		}
> +
> +		edid_size = read(fd_edid, edid, 512);
> +		threshold = THRESHOLD_PER_EDID_BLOCK *
> (edid_size / 128);
> +		if (lspcon_present || !strncmp(de->d_name,
> "card0-HDMI", 10))
> +			threshold *=
> HDMI_THRESHOLD_MULTIPLIER;
> +
>  		igt_mean_init(&mean);
>  		for (i = 0; i < CHECK_TIMES; i++) {
>  			struct timespec ts = {};
> @@ -76,22 +118,26 @@ igt_simple_main
>  		}
> 
>  		igt_debug("%s: mean.max %.2fns, %.2fus,
> %.2fms, "
> -			  "mean.avg %.2fns, %.2fus,
> %.2fms\n",
> +			  "mean.avg %.2fns, %.2fus,
> %.2fms, "
> +			  "edid_size %lu, threshold %d\n",
>  			  de->d_name,
>  			  mean.max, mean.max / 1e3,
> mean.max / 1e6,
> -			  mean.mean, mean.mean / 1e3,
> mean.mean / 1e6);
> +			  mean.mean, mean.mean / 1e3,
> mean.mean / 1e6,
> +			  edid_size, threshold);
> 
> -		if (mean.max > (THRESHOLD_PER_CONNECTOR
> * 1e6)) {
> +		if (edid_size == 0 &&
> +		   (mean.max >
> (THRESHOLD_FOR_EMPTY_CONNECTOR * 1e6))) {
>  			igt_warn("%s: probe time exceed
> 10ms, "
>  				 "max=%.2fms,
> avg=%.2fms\n", de->d_name,
>  				 mean.max / 1e6,
> mean.mean / 1e6);
>  		}
> -		igt_assert_f(mean.mean < (THRESHOLD_TOTAL
> * 1e6),
> -			     "%s: average probe time
> exceeded 50ms, "
> -			     "max=%.2fms, avg=%.2fms\n",
> de->d_name,
> +		if (edid_size > 0)
> +			igt_assert_f(mean.mean <
> (threshold * 1e6),
> +			     "%s: average probe time
> exceeded %dms, "
> +			     "max=%.2fms, avg=%.2fms\n",
> de->d_name, threshold,
>  			     mean.max / 1e6, mean.mean /
> 1e6);
> 
>  	}
>  	closedir(dirp);
> -
> +	igt_exit();
>  }
> --
> 1.9.1